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717 Cards in this Set
- Front
- Back
Darwin's Two Observations |
1. Members of a population vary in their inherited traits. 2. all species can produce more offspring than their environment can support, and many of these offspring fail t survive and reproduce. |
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Homology |
Traits shared by common descent from a common ancestor
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Fossil Record |
shows the evolutionary changes that have occurred in different groups of organisms |
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Biogeography |
evidence from the geographic(spatial) distributions of species. |
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analogy |
natural selection can cause similar traits to appear in unrelated groups. this is termed CONVERGENT evolution. |
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population |
group of interbreeding individuals in space and time.(individuals of the same species) |
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drift |
result of random processes. important in small populations. |
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migration |
gene flow between pops. can pring new alleles and thus traits. |
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gene flow |
the transfer of alleles into or out of a pop due to the movement of fertile individuals or their gametes. |
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speciation |
the process by which a species arises from an ancestral species |
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biological species concept |
a species is a group of pops whose members have the potential to interbreed in nature and produce viable offspring but do not produce fertile offspring with members of other groups. |
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allopatric speciation |
gene flow is interrupted when a pop is divided into geographically isolated subpops. |
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sympatric speciation |
rare. occurs within a pop, gene flow is reduced btw individuals by such factors as sexual selection and habitat differentiation. |
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taxonomy |
how organisms are named and classified. |
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binomial nomenclature |
the two part format of the scientific name for living organisms. |
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the order of hierarchical classification |
domain, kingdom, phlyum, class, order, family, genus, species. |
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phylogeny |
the evolutionary history of a species or group of species. based on shared HOMOLOGIES |
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shared ancestral characters |
homologies shared with distant ancestors. ex: mammals have vertebrae and jaws |
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derived characters |
homologies that are evolutionary novelties of particular clades. ex: mammals have hair and mammary glands. we rely on this to infer evolutionary relationships |
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prokaryotes |
split into archaea and bacteria. give info about original forms of life. tells us about evolutionary transition to eukaryotes. |
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the 3 shapes of prokaryotes. |
cocci, bacilli, spiral. all surrounded by cell wall composed of PEPTIDOGLYCAN(sugars linked by proteins). |
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gram-positive |
simple walls with a lot of peptidoglycan. stains purple. |
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gram-negative |
complex, outer membrane with less peptidoglycan. tends to be more toxic. stains pink. |
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capsule |
sticky coat of polysaccharide or protein |
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fimbriae |
attachment pili. proteinaceous spines. |
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taxis |
actively moving toward or away from stimulus. positive phototaxis: moving towards light. |
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endospore |
resting state of prokaryote locomotion. can remain dormant but viable for centuries. |
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prokaryotes |
do not have a nucleus. has a nucleoid region. may have accessory dna...plasmids(replicate indep. of chromosome). |
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ways of recombination in prokaryotes |
transformation- pick up DNA from environ. transduction- viruses(phages) carry bacterial DNA conjugation- one way transfer of DNA horizontal gene transfer- recombination btw species.
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conjugation process |
donor and receiver connected by SEX PILUS(mating bridge). F PLASMIDS is passed (f+ to F- site), which carries the F FACTOR and the plasmid genes. Hfr cell: F factor on chromosome: high frequency recomb. chromosome passed and recombined. |
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photoautotroph |
energy source: light carbon source: CO2, HCO3 or related compound |
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chemoautotroph |
energy source: inorganic chemicals(NH3, Fe2) carbon source: CO2 HCO3 or related compoud |
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photoheterotroph |
energy source: light carbon source: organic compounds |
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chemoheterotroph |
energy source: organic compounds carbon source: organic compounds |
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exotoxins |
proteins secreted by certain bacteria and other organisms |
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endotoxins |
are lipopolysaccharide components of the outer membrane for gram negative bacteria. are only release when the bacteria dies and the cell wall breaks down. |
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types of symbiosis |
mutualism(both benefit) commensalism(one benefits as other remains the same) parasitism(one benefits as one is harmed) |
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r plasmids |
have genes for enzymes that destroy antibiotics. increasingly common due to selection |
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bioremediation |
using bacteria to breakdown sewage, chemical spills, etc. |
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genetic engineering |
use cellular machinery to make chemicals we can use such as vitamins and antibiotics. |
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4 major clades of archaea |
extremophiles-lovers of extreme conditions halophiles- high saline and salt environ. thermophiles- high temp environ. methanogens- use CO2 and H2, species in anaerobic marshes. produces energy and methane waste.
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protists |
single celled eukaryotes (mostly). primary and secondary endosymbiosis.have contractile vacuoles to expel water. can be autotrophs, heterotrophs, or mixotrophs. |
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endosymbiosis |
way in which eukaryotes arose. |
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plastid |
in secondary endosymbiosis. acquired by engulfing photsynthetic eukaryote. proof with NUCLEOMORPH (remnant of eukaryote genome within 3rd membrane). |
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four main protist lineages |
excavata alveolates, stramenopiles, rhiziaria (SAR) archaeplastida unikonta |
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excavates |
protist lineage. mostly parasitic. most are flagellated. broken down into DIPLOMONADS + PARABASALIDS, and then EUGLENOZOANS. |
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euglenids |
mostly free living mixotrophs. in the excavates lineage and euglenozoans branch. |
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kinetoplastids |
free living predators and parasites. in the excavates lineage and eulenozoans branch. |
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stramenopiles |
protist lineage. hairy flagella. consist of DIATOMS, GOLDEN ALGAE, and BROWN ALGAE. |
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diatoms |
stramenopiles lineage. photosynthetic algae, with silica(glass) wall around cell. |
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golden algae |
stramenopiles lineage.unicelluar or colonial mixotrophs. many species form protective cysts that can survive for decades. |
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brown algae |
stramenopiles lineage. all multicelluar seaweeds and kelp. |
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alveolates |
protist lineage. grouped together based upon shared presence of alveoli beneath the cell membrane. Lineages are CILIATES, APICOMPLEXANS, and DINOFLAGELLATES. |
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ciliates |
alveolate lineage. cell covered in many short cilia rather than few long flagella. |
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apicomplexans |
alveolate lineage. parasites with complex life cycles. ex: plasmodium, which causes malaria. |
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dinoflagelates |
alveolate lineage. cellulose plates, with 2 flagella in groves. can cause neurotoxic shellfish poisoning. |
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dinoflagellate |
protist lineage. crimson tide. causes crimson tide due to high concentrations of carotenoids. |
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rhizarians |
protist lineage. amoeboid pseudopodia: cytoplasmic for locomotion, prey, capture. made up of FORAMINIFERANS, RADIOLARIANS, and CERCAZOANS. |
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foraminiferans |
lineage of rhizarians. shell of calcium carbonate. |
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radiolarians |
lineage of rhizarians. shell of silica, planktonic |
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cercazoans |
lineage of rhizarians. most are parasites and predators. most important consumers of bacteria in aquatic and soil ecosystems. |
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archaeplastida |
lineage of protists. includes the plants and related algae. what we study most in this class. consists of RED ALGAE, GREEN ALGAE, CHLOROPHYTES, AND CHAROPHYCEANS( and land plants) |
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unikonts |
lineage of protists. composed of two major groups, based upon general dna. includes AMOEBOZOANS(slime molds), OPISTHOKONTS(unicellular and mulitcellular flagellate heterotrophs)(including fungi and animals) |
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ecological role of dinoflagellates |
live in tissues of organisms in coral reefs, including coral and giant clams. |
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ecological role of parabasalids |
symbionts in termite guts to break down cellulose. |
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alternations of generations |
each generation gives rise to the other. |
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plants |
cell walls of cellulose evolved from single celled CHAROPHYTES kingdom plantae= Embryophytes |
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key features of plants |
alternation of generations sporopollenin walled spores made in sporangia multicellular gametangia apical meristems(areas of growth on shoot and root tips) |
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sporopollenin |
what makes the walls of plant spores tough and resistant to harsh environments. |
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stomata |
specialized pores that allow exchange of carbon dioxide and oxygen btw the atmosphere and the plant |
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vascular tissue |
specialized cells that transport water, nutrients, etc. |
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bryophytes |
non-vascular plants. liverworts, hornworts, and mosses. dominated by gametophyte but with prominent sporophyte. |
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protonemata |
one cell thick. produced by spores by germination. |
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in bryophytes |
sperm must swim through water to fertilize eggs in which plants? also, the sporophytes in this plant are dependant on parental gametophytes. |
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sporangium |
capsule on a stalk. opens via peristome. releases spores gradually: spread by wind. |
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sporophylls |
modified leaves bearing sporangia in vascular plants. |
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seedless vascular plants (ferns) |
sporangia organized into sori on the sporophylls. sporophyte stage larger than gametophyte stage. sporophyte not dependent upon gametophyte. leaves, roots, vascular tissue(xylem, phloem).
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the two extant phyla of seedless vascular plants |
lycophyta(more ancient) pterophyta(horsetails, ferns, more closely related to vascular plants).
they formed the first forests. |
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fungi |
multicelluar heterotrophs(absorb nutrients without ingestion unlike animals) can be parasitic or mutualistic. secretes enzymes that breakdown compounds. single celled is yeast. multicelled has filaments called hyphae. |
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cell structure of fungi |
filaments form masses: mycelia, increase surface area for uptake. cell wall of chitin. divided by septa and undivided, coenocytic fungi. |
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hyphae |
the network of tiny filaments in fungi that make up the body. |
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septa |
the hyphae in fungi is separated by this. generally has large pores to allow ribosomes, mitochondria,a and even nuclei to flow from cell to cell |
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mycelium |
fungal hyphae form and interwoven mass that infiltrates the material on which the fungus feeds. |
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huastoria |
some fungal species have specialized hyphae in which the fungi use to extract nutrients from or exchange nutrients with their host plants. |
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mycorrhizae |
mutualism with roots. fungi provides phosphorus, other nutrients, plant provides carbohydrates. all vascular plants have this. |
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ectomycorrhizae |
type of mycorrhizae. form sheaths around roots. and typically grow into the extracellular spaces of the root cortex. |
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arbuscular mycorrhizae |
extend branching hyphae through the root cell wall and into tubes formed by invagination of the root cell plasma membrane. haustoria. |
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ways of sexual reproduction in fungi |
plasmogamy: fusion of cytoplasm heterokaryon/dikaryon: 2 parental nuclei in 1 cytoplast( n+n ) karyogamy: fusion of nuclei (2n). spores(n) produced by meiosis. |
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unikonts |
where fungi evolved from. furthermore, the opisthokonts. |
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ascomycetes |
the clade in which there is the most fungal diversity. aslo called sac fungi, members of this group are common to many marine, freshwater, and terrestrial habitats. the defining feature is the production of spores (asci) during their sexual stage, most develop fruiting bodies, called ascocarps. they can also produce asexually by producing spores called conidia. |
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basidiomycetes |
the clade with the 2nd highest fungal diversity. important as decomposers. basidium(a cell in which karyogamy occurs, followed immediately by meiosis). reproduce sexually with basidiocarps, which are commonly called mushrooms. |
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mycosis |
harmful fungi. the general term for an infection in an animal by a fungal parasite. ex: ringworm, athletes foot. |
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lichen |
a symbiotic association btw a photosynthetic microorganism and a fungus in which millions of photosynthetic cells are held in a mass of fungal hyphae. |
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endophytes |
fungi or bacteria that live inside leaves or other plant parts without causing harm. |
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tow types of seed plants |
gymnosperms(conifers)
angiosperms( 90% of the total plants)(flowering plants) |
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seedless plants |
these plants are homosporous: which produce one kind of spore that usually gives irse to a bisexual gametophyte. |
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seed plants |
these plants are heterosporous: which produce megaspores that give rise to female gametophytes, and microsporangia produce microspores that give rise to male gametophytes. each megasporangium has one megasport, as each microsporangium has many microspores. |
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integument |
layer of sporophyte tissue. envelops and protects the megasporangium. gymnosperms are surrounded by one, as angiosperms usually have 2. |
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seeds |
embryo+food supply in protective coat, desiccation resistant, long dispersal distance.
ovules and pollen. WATER NOT NEEDED. |
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seedless plants |
flagellated sperm swim from male gametophyte(antheridium) to female gametophyte(archegonium). |
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seed plants |
tiny male gametophyte transported to female gametophyte. microspore develops into pollen grain( male gametophyte in sporopollenin coat ) Pollination: transport by wind or animal to femal ovule. |
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what does an ovule consist of in gymnosperm? |
megasporangium+megaspore+integument |
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fertilization of female gametophyte in gymnosperm. |
sperm transported via pollen tube through micropyle. fertilization occurs and megaspore turns into female gametophyte, which produces the egg. |
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angiosperms |
have seeds, flowers, and fruit. |
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flowers |
sex organs made up of up to 4 rings of specialized leaves.
sepals, petals, stamens, carpels. sepals and petals are sterile as stamens(male part) and carpels(female part, key feature in determining angiosperms from gymnosperms) are fertile. |
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fruits |
mature OVARY. variation in form: fleshy, dry, ect. aid in dispersal: can be carried by animals. |
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stamen |
male flower-parts. anthers on filaments; produce pollen. |
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carpels |
female flower part, produce female gametophytes. container in which seeds are enclosed. sticky stigma binds pollen; style connects it to ovary(1+ovules). |
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complete vs incomplete flowers |
flowers with all four organs vs flowers that lack one or more of these organs. ex: some lack stamens and some lack carpels. |
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angiosperm life cycle |
female gametophyte has large central cell with 2 nuclei ( n+n ). male gametophyte (pollen) has two haploid cells (generative and tube cells). pollen adheres to stigma of carpal, pollen tube grows down within the style of carpal. tube penetrates through the micropyle and discharges two sperm cells into female gametophyte(embryo sac). food supply for the seed. pollen releases 2 sperm. 1 sperm fertilizes embryo, 1 fuses with 2 nuclei in central cell resulting in ENDOSPERM(3n). |
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double fertilization |
in angiosperm life cycle. one fertilization event produces a zygote and the other produces a triploid cell, which is unique to angiosperms. |
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endosperm |
is the food supply for the seed. |
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cross pollination |
egg and sperm usually from different plants |
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generative cell |
male gametophyte has 2 haploid cell in angiosperms. this cell divides and forms 2 sperm. |
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tube cell |
male gametophyte has 2 haploid cells in angiosperms. this cell produces a pollen tube. |
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co evolution |
animals are dependent on plants and vice versa. this of insects and flowering plants may explain their great diversity. |
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vegetative growth |
two main systems being root system and shoot system. |
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leaves |
main organs of photosynthesis composed of blade and petiole(stalk) veins: vascular tissue of these conifer needles are in this group can be modified for support, protection, etc. |
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roots |
anchor, absorb minerals and water, store carbohydrates. two main types. |
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taproot |
main vertical root from primary root, many lateral roots. good for tall plants. |
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fibrous root |
no main root; lots of little branches; small plants |
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root hairs |
increase surface area for absorption. extenstions of root epithelial(dermal) cells many diff kinds of modified roots to serve specialized purposes. |
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adventitious roots |
root tissue emanating from stems or leaves (shoot system) |
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shoot system |
functions above ground. reproduction and photosynthesis. stems, leaves, flowers. |
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stems |
grow to increase the above ground volume occupied by branching thus facilitates dispersal of pollen and fruit; orients the plant in a way that maximized photosynthesis. |
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stem parts |
alternating nodes (where leaves attach) internodes (stem segments btw nodes) primary growth via apical bud, with branches formed by axillary buds. |
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apical dominance |
axillary bud growth inhibited by proximity of apical bud. stems may be modified for storage, asexual reproduction, etc. |
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flowers |
part of the shoot system, but involved with reproductive growth as opposed to vegetative growth |
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tissue systems |
plants are made up of three __ __ which are continuous throughout the organ systems of the plant |
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dermal tissue system |
part of tissue system. external protective covering, first line of defense. epidermis with waxy cuticle. periderm: protective outer tissue of woody plants |
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vascular tissue system |
part of tissue system. internal transport btw shoot and root systems. physical support. xylem, phloem, stele. |
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xylem |
vascular tissue system component. transports water+minerals from roots up to the shoots |
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phloem |
vascular tissue system component. transports sugars from where they are made(leaves) to where they are needed(flowers, fruits, roots, etc.) |
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stele |
xylem+phloem. vascular tissue system component. arrangement varies in roots(cylinder) and shoots(bundles) |
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ground tissue system |
part of tissue system. various tissues that are neither vascular nor dermal; specialized, responsible for metabolic functions. cortex: btw vascular tissue and dermal tissue pith: w/in vascular tissue |
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determinate vs indeterminate |
vertebrate growth is generally ___. grow is limited to embryonic/juvenile phase.
plant growth is generally __. made up of embryonic, juvenile, and adult organs. can keep growing and living until killed. |
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annuals/biennials |
complete life cycles in 1 or 2 years
perennials: can live for years |
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meristems |
perpetually embryonic tissue. can differentiate into other cell types. what makes indeterminate growth possible. two types
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apical meristems |
responsible for primary growth(increase in length) in the tips of roots and the apical and axillary buds of shoots. most growth in herbaceous plants. located behind the root cap: protects tip against soil, secretes lubricant |
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lateral meristems |
cause secondary growth(increase in girth) in woody plants cyclinders of cells that extend through stems and roots. vascular cambium: adds 2 degrees vascular tissue-xylem cork cambium: replaces epidermis w/ periderm |
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stem cells, derivatives |
____ are new cells that retain role of cell division in meristems. ___ cells divide and differentiate into different kinds of tissues, it is from these cells that all plant tissues arise. |
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3 diff zones of development; older cells further from the tip |
1. zone of cell division: meristem and immediate derivatives 2. zone of elongation: cells elongate, pushing tip forward up to 10x original length 3. zone of differentiation: cells mature to specialized cell types |
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pericycle |
outer most layer of cells. lateral roots originate from the ___. keeps vascular cylinders continuous |
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axillary bud meristems |
areas of meristem left behind by leaf primordia |
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lateral stems |
arise from axillary bud meristems, not the vascular tissue as with lateral roots |
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dermal ground vascular |
__ tissue: upper and lower epidermis. stomata. guard cells.
__ tissue: mesophyll=photosynthetic cells(space btw mesophyll allows for exchanges of gas)
__ tissue: branches throughout mesophyll; continuous w/ stem vascular tissue. surrounded by protective bundle sheath. |
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morphogenesis |
specific tissues/organs must develop at specific places(pattern formation) |
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polarity |
root to shoot axis. changes in this tells determines the fate of the cells. |
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phyllotaxy |
how leaves arranged on stem. determines light capture. |
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apoplast |
way of transport of water and solutes through plants. connected spaces outside living cells. cells walls open mesh of cellulose. inside of dead tracheids and vessels( xylem ). |
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symplast |
way of transport of water and solutes through plants. connected spaces inside of cells. must get through selective barrier (plasma membrane). cells connected by plasmodesmata. includes phloem. |
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transmembrane |
way of transport of water and solutes through plants. repeatedly crossing cell membranes. moving between the apoplast and the symplast. |
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protoplast |
living part of the cell, including plasma membrane, that presses against the cell wall, creating turgor pressure. making pressure potential. |
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aquaporins |
transport proteins for water. water moves through plant membrane faster than just diffusion. |
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bulk flow |
movement of fluid by pressure, indep. of solute. larger diameter xylem and phloem. |
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casparian strip |
waxy barrier that blocks apoplastic route; solutes must go through selective membranes of endodermis and enter symplast. from here, endodermis and living vascular cells export minerals to the xylem. |
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translocation |
movement of photosynthetic products in the phloem sap through sieve tubes. |
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eudicot |
two cotyledons. seeds vary in cotyledon development.
hypocotyl: lower part, connects to radical(embryonic root)
epicotyl: upper part, with immature leaves(embryonic shoot) |
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monocot |
have only one cotyledon=scutellum coleoptile: sheath surrounding embryonic shoot coleorhiza: sheath protects embryonic root |
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imbibition |
germination begins with the uptake of water, ___. causes expansion, seed coat ruptures. |
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eudicots |
radical emerges first, then hypocotyl. hypocotyl leads epicotyl and cotyledons(seed leaves). |
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monocots |
coleoptile(protects shoot) leads way up. shoot grows through. |
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pericarp |
ovary wall becomes the __. thickened wall of fruit; other fruit parts shed. |
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simple fruits |
from single or multiple fused carpels |
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aggregate fruits |
from flowers with multiple flowers in an inflorescence. ovary walls fuse. |
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accessory fruits |
incorporate other floral parts besides the ovaries |
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abiotic vs biotic |
wind and water dispersed vs lots of fruits dispersed by animals |
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fragmentation |
parent plant severed leads to two individuals. embryonic meristems facilitate to asexual reproduction by this. |
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apomixis |
asexual reproduction. seeds produced by mitosis; no fertilization. ex: dandelions |
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dioecious |
one sex or the other. chronologically or physically separate male and female parts |
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etiolation |
modifications of growth form for the dark. ex: a potato in a cupboard or buried.
no leaves: a waste in the dark, and would probably get wrecked no chlorophyll energy put into elongation |
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de-etiolation |
switch to typical above-ground morphology green leaves "greening", roots. |
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phytochromes |
etiolation and de-etiolation are mediated by these. a pigment that plants use to detect light. |
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phototropism |
plant horomones developed from studies of __ in oat seedlings. |
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auxin |
hormone in plant cell responses. isolated to elongate dark-side. any compound that promotes elongation of shoots; controls pattern formation |
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cytokinins |
hormone in plant cells. works with auxin to promote division and differentiation. stimulates cytokinesis. controls apical dominance slow aging of organs (inhibit protein breakdown) |
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ethylene |
hormone in plant cells that are produced in response to stress, including mechanical pressure; also in fruit and cells that die at maturity. 1) triple response (curves stem) 2) senescence (programmed death) 3) leaf abscission (leaf loss when water low) 4) fruit ripening (increase sugar, cell walls broken) |
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photomorphogenesis |
change shape in response to light |
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phototropism |
positive __ is growth towards light. |
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phytochrome |
red light is especially important for seed germination, shading, activates __. |
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photoperiodism |
a physiological response to day and night length, influences flowering time. |
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gravitropism |
have statoliths to determine direction of gravity. |
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thigmotropism |
plants respond to touch. rubbing plants regularly inhibits growth. |
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blastula |
hollow ball of cells. internal cavity is a blastocoel |
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gastrulation |
the zygote turns into a gastrula and the performs __, which is the invagination of the blastopore to form the beginning of the gut. |
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direct development |
offspring looks like a little version of the parent. ex: mammals, some insects. |
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indirect development |
young offspring (larvae) morphologically and ecologically diff than adult. must go through metamorphosis. ex: butterflies, some mollusks |
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choanoflagellate |
animals most closely related to colonial __ protists. similar to choanocytes of sponges. |
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ediacaran biota |
earliest large animal fossils |
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oder of eras |
Paleozoic Era (Cambrian explosion) ended with extinction (end-permian extinction)
Mesozoic Era (age of dinosaurs) ended with wipeout (end cretaceous extinction)
Cenozoic Era (modern era) humans. |
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animals |
have specific body plans as plants do not |
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HOX gene |
animal development under control of this gene. |
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aspects of body plans that provide insight into early animal evolution |
symmetry tissue organization body cavities |
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sessile or planktonic |
animals that sit in one place or drift in water. usually have radial symmetry |
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bilaterlly symmetrical |
the symmetry of animals with dorsal, ventral, anterior, and posterior end.
cephalization: having a front end (head) typical of animals that move under own power. |
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gastrulation |
___ leads to tissue organization. asymmetrical animals lack tissues therefor don't have this. radial and bilateral symmetrical animals do. |
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archenteron |
embryonic gut in result of gastrulation |
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endoderm |
tissue lining gut in result of gastrulation |
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ectoderm |
outer layer of cells in the nervous system in result of gastrulation. |
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diploblasts |
radially symmetrical ___: only two tissue types. basically a fancy gastrula |
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triploblasts, mesoderm |
bilateral __ have a third germ layer: __.
forms all other organs btw gut and outer surface such as muscles, gonads, circulatory system. |
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coelom |
in triploblastic animals. fluid-filled body cavity. |
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coelomates |
in triploblastic animals. body cavity lined with mesoderm. |
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pseudocoelomates |
in triploblastic animals. not completely lined with mesoderm, includes tissue derived from endoderm. |
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acoelomates |
in triploblastic animals. lack a body cavity fluid filled body cavity serves as a hydrostatic skeleton to antagonize muscles. |
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protostomes |
type of coelomate. coelem forms solid masses of mesoderm; expand to filled blastocoel. zygote cleavage is determinate spiral cleavage. gut develop: blastopore becomes the mouth |
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deuterostomes |
type of coelomate. mesoderm buds of endoderm of archenteron. zygote cleavage is indeterminate radial cleavage. gut development: blastopore becomes anus |
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bilateria |
group in which most animals belong to |
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major groups of animal phyla |
porifera=sponges
cnidaria=jellyfish, sea anemones, coral
lophotrochozoa= flatworms, mollusks, segmented worms.
ecdysozoa=arthropods, nematodes
deuterostomia=echinoderms, chordates |
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cnicaria |
phylum __. fancy gastrulas. radially symmetrical diploblasts.
two phases: medusa (mouth down, swimming, sexual stage). polyp (mouth up, sedentary, asexual stage).
no mesoderm, so no true muscles
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4 classes of phylum cnidaria |
hydrozoa
scyphozoa
cubozoa
anthozoa |
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3 main groups of phyla around before the cambrian explosion. triploblastic. bilateral symmetry. |
lophotrochozoa
ecdysozoa
deuterostomia |
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lophotrochozoa |
one group of bilaterians. contains annelida, mollusca, ectoprocta, rotifera, platyhelminthes, brachiopoda. |
|
platyhelminthes |
flatworms. acoelomates. trochophore type larvae (ciliated larvae). lack through-gut so it has gastrovascular cavity. unlike cnidarians, has organs to maintain osmotic balance. protonephridia with cells called flame bulbs mostly hermaphroditic. |
|
mollusks |
include taxa such as clams, snails, octopuses. 8 classes: polyplacophora, gastropoda, bivalvia, cephalopoda.
shell (except octopus) radula foot mantle cavity gonochoristic (separate sexes) |
|
lophophorates |
inderterminate radial cleavage, blastopore becomes anus. suspension feeders. ex: ectoprocta, brachiopoda. |
|
ecdysozoa |
arthropods, nematodes. all taxa molt their outer covering (go through ecdysis) |
|
arthropods |
type of ecdysozoa. covered by a jointed skeleton. chitin. gonochoristic |
|
nematodes |
type of ecdysozoa. long and cylindrical but unsegmented. diverse round worms. |
|
deuterostomia |
echinoderms, chordates. triploblastic, bilateral symmetry. vertebrates and invertebrates united in this one. two phyla: echinodermata (starfish, sea urchins, sand dollars) chordata (vertebrates(fish, frogs,chickens, apes) and related invertebrates) |
|
echinoderms |
part of deuterostomia. spiny skin. tube feet. broadcast spawning reproduction |
|
chordates |
deuterostomia part. all share certain traits: Notochord (long flexible rod of cells) hollow dorsal nerve cord (central nervous system) pharyngeal slits (pharynx, gills, jaws) post-anal tail (muscular tail extends past anus) |
|
chordates that lack vertebrae |
lancelets
tunicates (suspension feeders) |
|
2 clades of jawless vertebrates |
hagfishes
modern lampreys |
|
conodants |
lacked jaws. internal skeleton of cartilage. mineralized dental hooks |
|
chondrichthyes |
vertebrate with jaws (gnathostomes). unmineralized skeletons. buoyancy by storing oil in its liver. |
|
tetrapods |
"four legs" amphibians, reptiles, including birds and mammals. evolved from sarcopterygians. |
|
amphibians |
oldest tetrapod lineage. |
|
amniotes |
tetrapods with water-proof eggs. major innovation that got tetrapods fully on to land
extant clades: 1)reptiles (diapsids) 2)mammals (synapsids) |
|
synapsid |
mammals are __ amniotes. |
|
monotremes |
extant clade of mammals. egg-laying mammals; only in australia; no nipples but milk |
|
marsupials |
extant clade of mammals. mammals with a pouch. only in australia, north and south america. ex: possum |
|
eutherians |
extant clade of mammals. placental mammals. global. HUMANS. |
|
hominins |
20 extince species closely related to humans and chimps diverged from a common ancestor. share 99% DNA. |
|
physiology |
biological function; how things work |
|
epithelial tissue |
epithelium. closely packed cells lining surfaces. barrier against injury, infection, dehydration. |
|
simple squamous |
type of epithelial tissue. thin and leaky. found: diffusion surfaces like blood vessels, lungs |
|
columnar |
type of epithelial tissue. tight cell-cell junctions. found: where absorption is important. line intestines. |
|
stratified squamous |
type of epithelial tissue. layers of cells. found: sloughed off as new cells arise. line abraded surfaces, mouth, vagina. |
|
pseudostratified columnar epithelium |
type of epithelial tissue. columnar cells w/ varying height of cilia; found: sweep mucus. esophogous. |
|
cuboidal |
type of epithelial tissue. built for secretion. found: glands, kidneys. |
|
connective tissue |
bind and support other tissues of the body. provide support matrix for organs. |
|
loose connective tissue |
connective tissue. binds epithelium, holds organs in place.
collagen and elastin |
|
cartilage |
connective tissue. collagen fibers in protein-carbohydrate matrix; secreted by chondrocytes. |
|
fibrous connective tissue |
connective tissue. dense collagen fibers; tendons (muscle to bone) and ligaments (bone to bone) |
|
adipose tissue |
connective tissue. fat for storage, cushioning, and insulation. |
|
blood |
connective tissue. liquid matrix composed of plasma, red and white blood cells, and platelets. |
|
bone osteoblasts |
connective tissue. secrete collagen matrix that becomes mineralized. |
|
muscle and nervous |
___ and ___ tissue are the basis of animal behavior. |
|
nervous tissue |
tissue that converts external stimuli to electronic impulses, conduct impulses. |
|
glia |
associated cells that protect and nourish neurons |
|
muscle tissue |
contractile cells with actin and myosin filaments; most abundant, uses most energy. 3 types: skeletal= voluntary movements; striated smooth= involun. movements; not striated cardiac= involun. movements; striated |
|
nervous and endocrine |
__ and __ systems coordinate the actions of organ systems. |
|
nervous system vs endocrine system |
sends point to point messages, short duration. immediate responses, coordinating movement.
broadcast molecular signals, tissues respond, and longer duration. regulation of growth, development, reproduction, metabolism, digestion.
both maintain homeostasis. |
|
hypothalamus |
body's thermostat |
|
thermogenesis |
make more heat through muscle contraction in endotherms |
|
countercurrent exchange |
reduce heat loss through this process. fish use it. cooled blood of extremities flows back past warm arteries. |
|
acclimitization |
changing anatomy/physiology to better suit environment; reversible. ex: moose up a mountain. |
|
bioenergetics |
how animals allocate energy for different functions |
|
basal metabolic rate |
minimum metabolic rate. at rest, no stress. for non growing endotherms |
|
torpor |
physiological state of decreased activity and very low metabolic rates. ex: hibernation (during winter), estivation (during summer), daily (hummingbirds let temp. drop when inactive). |
|
essential nutrients |
whatever an animal can't synthesize. amino acids, fatty acids, vitamins, minerals |
|
vitamins |
two types. water-soluble and fat-soluble. organic compounds |
|
minerals |
any inorganic elements needed in various amounts. |
|
undernourishment |
shortage of food energy. body begins to break down own proteins, etc. once the sugars/fats exhausted. |
|
4 stages of food processing |
ingestion=eating
digestion=break down food to usable molecules.enzymatic hydrolysis.
absorption=cells take up digestive product
elimination= removal of unassimilated waste |
|
bulk feeders |
eat large pieces of food. most animals. humans. |
|
fluid feeders |
eat other organisms' body fluids; mosquitos |
|
filter feeders |
filter particles from water; whales |
|
substrate feeders |
ingest substrate, eliminate most of it; earthworms. |
|
accessory glands |
salivary glands, pancreas, liver, gall bladder are __ __. |
|
peristalsis |
waves of smooth muscle contraction |
|
sphincters |
segments isolated by __: muscular closures |
|
amylase |
enzyme that hydrolyzes starch and glycogen (carbohydrates) in mouth. |
|
mucin |
glycoprotein lubricant in mouth that protects lining of oral cavity and facilitates swallowing. protects against tooth decay. |
|
pharynx |
__ opens to 2 passage ways: trachea and esophagus. |
|
epiglottis |
cartilage flap that closes flap during swallowing |
|
esophagus |
connects the oral cavity to the stomach.
striated muscle: upper part; voluntary swallowing
smooth muscle: lower part; involuntary peristalsis |
|
HCl |
lowers pH of stomach to 2 (acidic) denatures proteins |
|
pepsin |
protease (breaks peptide bonds) |
|
parietal cells |
secrete H+ and Cl- separately |
|
chief cells |
secrete pepsinogen (inactive pepsin) |
|
small intestine sections |
duidenum, jejunum, and ileum |
|
duodenum |
site of digestion in the small intestine, receives secretions from the pancreas, liver and gall bladder. pancreas: neutralizes acidic chyme, secretes proteases, amylases and nucleases liver: produces bile; stored in gall bladder (lipid digestion) |
|
jejunum and ileum |
sites of absorption in small intestine. villi and microvilli increase surface area. nutrients move through epithelial cells. |
|
hepatic portal vein |
capillaries lead to the __ __ __ for processing by liver: controls chemical composition |
|
lacteals |
fat (triglycerides) components are too large to go through microvilli. they are processed in cells and sent to lymphatic system via __. |
|
large intestine |
recovers water in the alimentary canal. colon+cecum+rectum. connects to small intestine at T-junction: colon one way, cecum the other (pouch for fermenting unassimilated material)
appendix: extension of human cecum |
|
colon |
water reapsorption. ions pumped out of colon to draw out water. |
|
carnivores |
better developed incisors and canines |
|
herbivores |
broad molars for grinding. also have longer alimentary canals than carnivores. |
|
omnivores |
unspecialized teeth |
|
cellulase |
most animals lack this enzyme that breaks down cellulose of plant cell walls. some herbivorous vertebrates have mutualistic organisms in their guts. |
|
ruminants |
cows, sheet, etc.: 4 chambered stomach |
|
pancreas and liver |
___ and ___ control negative feedback |
|
circulatory systems |
facilitate exchange with the environment. |
|
open circulatory systems |
anthropods, most mollusks. circulatory fluid (hemolymph) in direct contact with organs; same as interstitial fluid. advantages: lower pressures, can use fluid as hydrostatic skeleton, body movements help circulate. |
|
closed circulatory systems |
annelids, cephalopods, vertebrates. circulatory fluid (blood) in vessels, separate from interstitial fluid. advantages: high blood pressure, faster delivery of O2, nutrients |
|
cardiovascular system |
composed of pumping heart with 2+ chambers atrium: receives blood ventricle: pumps blood away |
|
pulmonary circuit |
right side: to lungs, oxygen-poor blood to lungs
|
|
systemic circuit |
left side: to body |
|
atrioventricular valve (AV): semilunar valves: heart murmur: |
between chambers btw ventricles and arteries defective valve leads to back-flow |
|
sinoatrial node: |
cause atria to contract, empty into ventricles |
|
atrioventricular node |
after .1s delay, ventricles contract |
|
lumen, endothelium |
all vessles (capillaries, arteries and veins) have and open __ lined by __. |
|
arteries |
layer of smooth muscle, then layer of elastic connective tissue. |
|
veins |
layer of smooth muscle and connective tissue. |
|
precapillary sphincters |
close off paths thru capillary beds |
|
lymphatic system |
network of small vessels that drains excess interstitial fluid: lymph eventually returned to circulatory system moves by smooth muscle contraction |
|
plasma |
90% water with dissolved salts, proteins, gases, wastes, horomones |
|
erythrocytes |
red blood cells. O2 transporter. lack nuclei, mitochondria, full of hemoglobin (oxygen transport protein) |
|
leukocytes |
white blood cells. perform various immune functions. |
|
platelets |
cell fragments involved in blood clotting |
|
clotting |
___: damage plugged by platelets and reinforced by fibrin protein |
|
partial pressure |
the fraction of the total pressure exerted by air. |
|
countercurrent exchange |
___ ___ of respiratory medium maintained by ventilation. Capillaries flow in opposite direction. removes 80% of dissolved O2. |
|
tracheal system |
insects. series of air tubes that branches throughout body. gas exchange does not involve circulatory system. |
|
lungs |
vertebrates. air in through nostrils (filtered, warmed, moistened), to larynx and into trachea. branches into 2 bronchi, which continue to branch into bronchioles, tiniest bronchioles end in alveoli (terminal sacs where gas exchange happens |
|
positive pressure breathing |
amphibians. push air in by shrinking oral cavity |
|
negative pressure breathing |
mammals. pull air in by expanding thoracic cavity with muscles and diaphragm (skeletal muscle) controlled by breathing control centers in brain by negative feedback |
|
Why is hemoglobin necessary? |
Necessary because O2 has low solubility in water. |
|
pathogens |
foreign invaders that try to co-opt organismal resources; cause disease. prokaryotes, eukaryotes, viruses. |
|
immune system |
necessary to avoid/limit infection. keep foreign invaders out. recognize self vs nonself once invaders inside. detection of non-self accomplished by molecular recognition. |
|
innate immunity |
active all the time. non-specific. found in all animals and plants. inhibit/detect broad range of pathogens first defense only line of defense in invertebrates |
|
acquired immunity |
adaptive immunity: response enhanced by previous infection, highly specific. only vertebrates responds mostly strongly to pathogens it recognizes. slower but more specific. |
|
humoral response |
antibodies defend against infection in body fluids |
|
cell-mediated response |
cytotoxic lymphocytes defend against infection in body cells |
|
lysozyme |
digest bacterial cell walls of microbes |
|
hemocytes |
__ in hemolymph: phagocytosis and various chemical protections. |
|
antimicrobial peptides |
disrupt pathogen plasma membranes of fungi and bacteria. |
|
toll-like receptor |
receptors that recognize pathogen bits in innate immunity. activation triggers innate immune response. |
|
neutrophils |
phagocytic cell. circulate the blood |
|
macrophages |
phagocytic cell. some migrate throughout the body, others reside permanently in organs and tissues |
|
dendritic cells |
found in tissues that contact the environment (skin). phagocytic cell. |
|
eosinophils |
phagocytic cells. located beneath mucosal surfaces. |
|
antimicrobial proteins |
include interferons and the complement system |
|
interferons |
antimicrobial protein. produced by cells infected by viruses; signal other cells to produce anit-viral compounds |
|
complement system |
antimicrobial protein. proteins in blood plasma, activated by microbial substances; leads to bursting of cells. also part of inflammatory response. |
|
inflammatory response |
release of signaling molecules following infection/injury. innate immunity |
|
mast cells |
__ __ release histamine, a signaling molecule. causes vessels to dilate, becoming more permeable. |
|
macrophages |
activated __ also release signaling molecules, cytokines, that promote blood flow |
|
systemic vs local inflammatory responses |
increase production of white blood cells (macrophages+lymphocytes)
fever: accelerate repair? kill invading cells? |
|
natural killer cells |
innate immunity response. inflammatory response. can recognize and chemically-destroyed destroy diseased cells. normal body cells produce class 1 MHC surface proteins. infected or cancerous do not NK cells look for such cells and kill them |
|
immunological memory |
vertebrates: acquired immunity involves ___ __. |
|
B cells |
mature in bone marrow. type of lymphocyte. |
|
T cells |
move from bone to the thymus. type of lymphocyte. |
|
antigen receptors |
lymphocytes activated by binding to specific antigens displayed on the cell surfaces, using __ __. Causes lymphocytes to divide: one daughter used now and one saved for later (memory cell) |
|
antigen receptors (antibodies) |
B cells secrete __ __ (__): bind to foreign molecule. some t cells detect and kill infected cells. other t cells "help" activate other lymphocytes |
|
antigens |
foreign molecules recognized by lymphocytes. typically proteins or polysaccharides. may be on surface of pathogens. T and B lymphocytes have them in plasma membrane |
|
plasma cells |
some b lymphocytes (__ __) produce antigen receptors= antibodies (immunoglobulin) |
|
epitope |
small part of antigen that is recognized by and bound to antigen receptor. one antigen can have many of these. |
|
Y-shaped |
B cell receptors are this shape. 4 polypeptides. 2 heavy, 2 light. linked by sulfide bonds. heavy chains "transmembrane"
c trans-membrane, with sulfide bonds V at tips: forms 2 asymmetrical antigen binding sites. |
|
T cell receptor |
has a and B chains linked by sulfide bonds. C and V regions, but with 1 antigen binding site.
|
|
free antigens |
b cell receptors bind __ __. |
|
"presented" antigens |
T cells only bind __ __. |
|
effector cells |
activated B or T cells divide many times. A type of daughter cell. short-lived, attack antigen/pathogen. innate immunity. |
|
memory cells |
activated B or T cells divide many times. A type of daughter cell. long-lived, with same antigen receptor. innate immunity. |
|
adaptive immunity |
primary and secondary immunity responses. |
|
primary immune response |
adaptive immunity. production of effectors (plasma cells) peaks 10-17 days.
production of memory cells leads to immunological memory |
|
secondary immune response |
second exposure. peaks faster (2-7 days) and higher. |
|
helper t cells |
enhance humoral and cell-mediated responses. binds to antigen presenting macrophage, dendritic cell, or b cell: class II MHC, TCR (T cell receptor) and accessory protein (holds complex together). cells exchange signaling molecules (cytokines): stimulates B cells (humoral response) and cytotoxic T cells (cell-mediated response) |
|
humoral immune response |
activation and clonal selection of effector B cells. "antibody mediated response" secrete antibodies that circulate in blood and lymph. defend against extracellular pathogens |
|
cell-mediated |
cytotoxic T cells= effector T cells activated by binding class I MHC, TCR and accessory protein on infected cell and cytokines from helper T secretes proteins that rupture cell membrane and initiate apoptosis. |
|
MHC proteins (major histocompatibility complex) |
___ ___ on the surface of cells presents antigens to T cells. This complex makes the proteins that present antigens on cell surface. |
|
Class I MHC |
In (almost) all cells bind foreign peptides synthesized in cell recognized by cytotoxic T cells |
|
Cass II MHC |
in macrophages, B cells, dendritic cells (antigen-presenting cells) bind foreign fragments acquired through phagocytosis recognized by helper T cells: influence activities of B and cytotoxic T cells |
|
B cell |
activated _ __ produces memory cells and plasma cells that release antibodies. |
|
neutralization |
antibodies interfere with pathogen function. binds to virus, bacterium or toxin. |
|
opsonization |
antibodies interfere with pathogen function. binding sites for macrophages. |
|
activation of complement system |
antibodies interfere with pathogen function. form "membrane attack complex" with __ __, cell lyses. |
|
osmoregulation |
concentration of body fluids similar to surrounding environment: no specializations for __. |
|
osmosis |
water moves from low solute to high solute concentration. sea water is hyperosmotic, blood hypoosmotic. |
|
osmoconformer |
body fluid isoosmotic with environment |
|
osmoregulator |
body fluid regulated many marine invertebrates most tolerate narrow range of temps (stenohaline) a few can tolerate wide range (euryhaline) |
|
ammonia |
protein/nucleic acid metabolism results in __. highly toxic but highly soluble. aquatic organisms can let it diffuse from body surface. |
|
urea |
many vertebrates convert ammonia and CO2 to __. lower toxicity. |
|
uric acid |
reptiles + birds, terrestrial invertebrates convert ammonia to __ __: lower toxicity. nonsoluble (little water needed). most costly to produce. |
|
urine |
__ is produced in 4 steps in the excretory system. built on a tubular theme. |
|
transport epithelium |
some surface specialized to move solutes/water into/out of circulatory fluid. |
|
filtration |
first step of urine production. body fluid forced through semi-permeable membrane (water, ions pass: proteins, etc. do not). |
|
reabsorption |
2nd step of urine production. water and ions selectively taken back. |
|
secretion |
3rd step of urine production. wastes, etc, actively added to filtrate. |
|
excretion |
4th step of urine production. remaining filtrate (urine) leaves the body through urethra. |
|
protonephridia |
___ of flatworms: beating cilia inside flame bulb draw body fluid into tubules, filtrate excreted. function: osmoregulation rather than excretion metabolic waste diffused across body surface or eliminated through the mouth. excretory system of flatworms |
|
metanephridia |
___ of annelids: beating cilia draw body fluid in the tubes. reabsorption in with capillaries. function: osmoregulation and excretion. excretory system or annelids. |
|
malpighian tubules |
__ __ of insects: immersed in hemoplymph. solutes secreted by transport epithelium from hemolymph. water reabsorbed, nitrogenous waste/uric acid excreted. excretory system of insects |
|
kidney, ureter, urinary bladder, urethra |
each __ served by renal artery and renal vein. fluid leaves each kidney via __. each ureter drains to common __ __. drains to outside via __; controlled by sphincter muscles. |
|
renal cortex, renal medulla |
kidney is composed of out __ __ and inner __ __; lots of blood vessels and excretory tubules. |
|
nephron, bowman's capsule, glomerulus. |
in kidney. functional unit of kidney. one long tubule; begins with __ __ surrounding cluster of capillaries (__). |
|
proximal tubule, loop of henle, distal tubule, collecting duct, renal pelvis |
path of filtrate within nephron
Bowman's capsule to __ __. then to __ of __; in mammals extends into renal medulla. then to __ __, then to common __ __. collecting ducts join to form __ __ which drains to ureter. |
|
afferent and efferent arterioles, peritubular capillaries, vasa recta. |
each nephron served by circulatory system. __ and __ __ lead to and from glomerulus. __ __ around tubules __ __ associated with loop of Henle |
|
proximal tubule |
filtration step. first stage of concentration of wastes. |
|
descending loop of henle |
filtration process. reabsorption of water. permeable to water but not salts |
|
ascending loop of henle |
filtration process. reabsorption of NaCl. permeable to NaCl but not water. active and passive transport. |
|
distal tubule |
filtration process. regulates NaCl out K+ in. |
|
collecting duct |
filtration process. further concentrates filtrate. moves down gradient. loses water, actively reabsorbs NaCl. in inner medulla, permeable to urea: water diffuses out to contribute to high osmolarity. |
|
antidiuretic hormone (ADH) |
released in response to high blood osmolarity. made in hypothalamus, stored in pituitary. increases water permeability, concentrates urine. |
|
Renin-angiotensin-aldosterone system (RAAS) |
hormone that maintains blood pressure. when blood pressure is low (dehydration), initiates enzyme cascade resulting in arterial construction. |
|
endocrine signaling |
hormones circulate in blood/hemolymph and activate target cells |
|
paracrine and autocrine signaling |
__ and __ signaling: secrete molecules, "local regulators", that act over short distances, reach target cells by diffusion. |
|
synaptic and neuroendocrine signaling |
__ and __ signaling: network of neurons transmit chemical signals (neurotransmitters) to other cells across synapses.
specialized neurosecretory cells secrete molecules, NEUROHORMONES, that diffuse from nerve cell endings into the bloodstream. |
|
pheromones |
chemicals released outside the body to affect another organism. ex: warning, attracting mates. |
|
water-soluble hormones |
cell membrane receptors initiate signal transduction and response. |
|
lipid-soluble hormones |
move across cell membrane, receptors within cell/nucleus. receptor hormone complex interacts directly with DNA. |
|
insulin and glucagon |
ex of antagonistic pair: __ and __. both hormones produced in pancreas. increased blood glucose leads to release of insulin. decrease in blood glucose leads to release of glucagon (targets liver to convert glycogen to glucose) |
|
type I diabetes |
autoimmune disorder kills cells that make insulin. lots of glucose in blood, but cells not taking it up. |
|
type II diabetes |
mostly the result of life style (overweight, lack of exercise). insulin produced but target cells don't take up glucose.
|
|
hypothalamus |
vertebrate __: endocrine gland in brain; important for nervous/endocrine coordination. |
|
pituitary gland |
neurosecretory signals from hypothalamus travel to the __ __ (actually 2 fused together) |
|
posterior pituitary: |
stores two hormones from hypothalamus. Antidiuretic hormone, oxytocin |
|
anterior pituitary |
makes several hormones that are released upon stimulation from hypothalamus. acts on a wide variety of targets. tropic hormones: those that regulate other endocrine glands. |
|
adrenal glands |
involved in stress behavior. on kidneys (renal organs) with 2 parts, adrenal cortex and adrenal medulla. |
|
epinephrine and norepinephrine |
stress leads to the release of these 2 amines from the adrenal medulla. prepares body for short-term excitement. |
|
ACTH |
stress leads hypothalamus to release tropic hormone (____) that stimulates adrenal cortex. |
|
mineralocorticoids and glucocorticoids |
ACTH released from the hypothalamus in response to stress, releases two main types of steroids for long-term stress response: __ and __. |
|
sexual reproduction |
fusion of haploid (n) gametes to form dipoid (2n) zygote |
|
internal fertilization |
games mingle in female's reproductive tract |
|
fission |
one individual splits into two of similar size |
|
budding |
one individual grows from another. ex: hydra, colonial corals |
|
gragmentation |
breakage, followed by regeneration. ex: starfish |
|
parthenogenesis |
offspring develop from unfertilized eggs. |
|
gonads |
the sex of an individual is determined by its __. males have testes that produce sperm.
females have ovaries that produce ova (eggs) |
|
external fertilization |
can occur in aquatic environments. spawning: both sperm and eggs released to water.
some species synchronize based upon environmental cues. |
|
gametogenesis (oogenesis) |
production of gametes. must be coordinated with systems to support fertilized embryo. eggs relatively large: DNA+nutrients for embryo
sing meiotic egg produced. much of process completed b4 birth. mature gametes produce until 50. long pauses in meiotic divisions |
|
spermatogenesis |
males. production of sperm is simple. lots all the time. sperm is small: DNA+little else.
all four products become gametes meiotic division timing occurs throughout adulthood meiotic divisions: sperm produced in continuous sequence from precursors to mature gametes. |
|
key ways spermatogenesis differs from oogenesis. |
1) number of gametes formed by meiosis 2) timing of meiotic division 3) pace of meiotic divisions |
|
penis |
external sex organ. urethra and erectile tissue. relies on hydrostatic pressure (blood) during copulation other mammals have a bone (baculum) to maintain rigidity |
|
scrotum |
external sex organ. contains testes outside the body. spermatogenesis happens at lower temp than body testicles: testis within a scrotum. |
|
testes |
internal sex organ. composed of highly coiled SEMINIFEROUS TUBULES. |
|
seminiferous tubules |
inside testes. produces sperm.
leydig cells (endocrine): located btw tubules, make testosterone, etc. |
|
epididymis |
internal sex organ. highly coild, 6m tube. sperm take 3 WEEKS to mature. |
|
ejaculation |
the process of getting sperm form the inside to the outside.
from epididymis to muscular VAS DEFERENS, and around the bladder.
ejaculatory duct: opens to urethra. |
|
seminal vesicles |
most of the volume of semen; contains mucus, sugar, ascorbic acid, and prostaglandins. |
|
prostate gland |
adds more fluid to semen, including anticoagulant enzymes and nutrients. |
|
bulbourethral gland |
secretes mucus to neutralize any urine (acidic) in urethra. this gland releases this to add to semen. |
|
spermatogonium |
diploid stem cells within testes.
primary spermatocyte: 2n secondary spermatocytes: nx2 products of meiosis 1 spermatids: nx4...products of meiosis II sperm cells: nx4...mature in seminiferous tubules |
|
GnRH (gonadotropin-releasing hormone) |
hormone from hypothalamus, stimulates anterior pituitary to secrete FSH and LH (the gonadotropin molecules) |
|
FSH (follicle stimulating hormone) and LH (luteinizing hormone) |
hormones from pituitary. tropic hormones that target gonads and regulate sex hormone reproduction.
__: acts on sertoli cells in seminiferous tubules __: acts on leydig cells btw seminif. tubules |
|
gonads |
produce sex hormones
males: androgens, like testosterone
females: estrogen, like estradiol and progesterone |
|
negative feedback |
hormonal control of spermatogenesis is based on __ __. |
|
sertoli cells |
what FSH acts on. nourish developing sperm. promote spermatogenesis.
the cells produce INHIBIN, which regulates pituitary. |
|
leydig cells |
what LH acts on. secretes testosterone, which promotes spermatogenesis. |
|
testosterone |
inhibits both hypothalamus and anterior pituitary |
|
pvaries |
paired __ are the female gonads |
|
oocytes |
outer layer of follicles: __. partially developed eggs surrounded by support cells. 1-2mill follicles at birth. only 500 can mature btw puberty and menopause. |
|
ovulation |
after __ (release of ovum), follicle becomes CORPUS LUTEUM that makes estrogen |
|
corpus luteum |
what follicle becomes after ovulation. makes estrogens. degrades if not fertilized. |
|
oviducts |
fallopian tubes. leads to uterus (womb). connects to vagina via CERVIX. uterus lined by ENDOMETRIUM: many blood vessels to support developing fetus. |
|
oogonium |
___:diploid 2n stem cell withing follicle of ovary primary oocyte: 2n. present at birth secondary oocyte: n +polar body (one per month;stops mid meiosis II) fertilized egg: 2n +polar body ovulation + sperm initiates completion of meiosis II and develops into 2n zygote. follicle becomes corpus luteum. |
|
ovarian cycle |
reproductive cycle. procudes ovum. lasts about 28 days. under control of same hormones as spermatogenesis.
GnRH--FSH and LH released--FSH stimulates follicle growth--follicle secretes setradiol--low estradiol inhibits anterior pituitary--leads to spike in FSH and LH then estradiol then gonadotropins--follicle ruptures, releasing 2 oocyte (ovulation)--luteal phase follows; LH stimulates development of corpus luteum, which secretes estradiol and progesterone.--decrease in gonadotropin causes corpus luteum to degrade.--in the absense of pregnancy, the whole cycle starts again. |
|
uterine/menstral cycle |
synchronized with the ovarian cycle hormonally prepares the uterus to support a fetus. estradiol from follicles causes endometrium to thicken;proliferative phase--after ovulation, estrogens stimulate development of uterine lining, including arteries and glands;secretory phase.--when corpus luteum degrades, hormone levels drop and endometrium degrades, releasing blood. menstrual flow phase. coordination of ovarian and uterine cycles until menopause (46-54 years) |
|
menopause |
46-54 years of age. coordination of ovarian and uterine cycle stops. other mammals have seasonal or annual ESTROUS CYCLE ("in heat") when females are receptive. |
|
fertilization |
"conception". sperm fuses with mature oocyte in oviduct. 24 hours: first cleavage 2-3 days: zygote reaches uterus 1 week: blastocyst (hollow ball of cells), implants in endometrium develops into fetus. |
|
hGC (human chorionic gonadotropin) |
embryo produces ___. works like LH to keep corpus luteum from degrading. keeps progesterone levels up. can be detected in uring;pregnancy test |
|
preganncy |
one or more embryos in the uterus |
|
gestational period |
first 2-3 weeks: embryo nutrients from endometrium
placenta: forms from embryonic and material tissue; blood vessels from both exchange nutrients, gases, wastes, etc.
after 8 weeks of ORGANOGENESIS, embryo termed a fetus |
|
estradiol and oxytocin |
after 38 weeks, interaction btw these hormones and local regulators leads to labor. dilation of the cervix contraction of uterus to push fetus out more contraction to deliver placenta |
|
key stages to animal development |
fertilization cleavage gastulation organogenesis
|
|
vitelline layer |
extracellular matrix of egg |
|
jelly coat |
protects egg and attracts sperm. |
|
acrosomal reaction |
contact of sperm and egg cause this. |
|
acrosome |
vesicle at sperm tip with hydrolytic enzymes break down jelly |
|
acrosomal process |
structure with proteins that bind receptors on eggs. |
|
depolarization |
fusion of sperm and egg leads to change in membrane potential. fast block to polyspermy. not in mammals |
|
cortical reaction |
fusion also initiates __ __. vesicles in cortex (outer part) fuse with plasma membrane. contents (enzymes) lead to fertilization envelope and SLOW block to polyspermy. |
|
cleavage |
earliest divisions of life, rapid. cells divide by mitosis, but don't grow in size.
blastomeres: individual (smaller) cells |
|
blastula |
hollow ball of cells with a BLASTOCOEL. |
|
cytoplasmic determinants |
proteins, mRNA, etc. in various places. yolk: stored nutrients (vegetal axis) and non yolk side is animal pole
frogs |
|
yolk |
presence of __ influences shape of blastula |
|
gastrulation |
the process by which adult germ tissues are formed. the ball of cells turns into a structure with 2-3 tissue layers and a gut (gastrula) |
|
sea urchin gastrulation |
3 tissues (germ layers) are ectoderm, endoderm, and mesoderm
starts at vegetal pole. vegetal plate forms. vegetal plate invaginates and becomes archenteron.
digestive tubes form, lined by endoderm |
|
archenteron in sea urchin |
vegetal plate invaginates and becomes ___. opening is the blastopore (future anus)
|
|
gastulation in frog |
blastopores form on dorsal side at dorsal tip; extends around blastula.
future endoderm and mesoderm expand by INVOLUTION; shrinks blastocoel
end of gastrulation, blastopore surrounds YOLK PLUG. |
|
organogenesis |
once germ layers present, cells differentiate to form organs. formation of notochord and so on |
|
notochord |
condensation of dorsal cells above archenteron |
|
neural plate |
cells curve inward to form a neural tube (becomes CNS) |
|
neural crest cells |
cells that migrate to form other nerves. |
|
cell differentiation and morphogenesis |
organogenesis continues into __ and __. (leads to adult organs). |
|
blastocyst |
mammalian blastula
trophoblast: outer epithelium (forms placenta) inner mass cells: embryonic stem cells |
|
trophoblast |
initiates implantation. secretes enzymes to break down endometrium. thickens, send extensions to maternal blood vessels.
inner mass cells form epiblast and hypoblast |
|
morphogenesis |
when cells change shape and move relative to each other. |
|
cell adhesion molecules (CAMs) |
morphogenesis. cells form stable tissues using __ __ __. usually glycoproteins on cell surfaces. allow cells to recognize others and bind them with specific receptors. |
|
extracellular matrix |
migration of cells also mediated by __ __: mesh of macromolecules outside of cells. |
|
induction |
changes in gene expression based upon intercellular interactions |
|
developmental potential |
as cell lines develop, cells lose their __ __: they can become fewer different types of cells |
|
pattern formation |
__ __ is controlled by induction by induction providing positional info. (limb development in a chick). |
|
apical ectodermal ridge (AER) |
organizer region. at tip of bud. secretes growth factor that extends limb bud, proximal-distal. |
|
zone of polarizing activity (ZPA) |
organizer region. posterior, proximal location. organizes anterior-posterior of development: furthest become anterior. |
|
peripheral nervous system |
sensory input gets integrated into the central nervous system. response is transmitted by the __ __ __. |
|
structural neurons |
neurons that transmit info from eyes and other sensors that detects external stimuli or internal conditions |
|
interneurons |
neurons that form the local circuits connecting neurons in the brain |
|
motor neurons |
neurons that transmit signals to muscle cells, causing them to contract. |
|
glial cells |
nourish, insulate, and regulate neurons. |
|
cell body |
part of neuron that houses most of cytoplasm. nucleus. |
|
axon hillock |
where axon joins cell body, where signals are generated |
|
sodium potassium pump |
brings k in and send Na out. |
|
ion channels |
channels that let ions move down their gradient |
|
voltage potential |
net movement of charge is what creates __ __. |
|
hyperpolarization |
membrane potential more negative |
|
depolarization |
less negative of membrane potential activates voltage gated Na channels |
|
refractory period |
time btw action potentions, Na closed, AP not possible. |
|
glial cells |
speed of propagation increases with "insulation" by __ __. |
|
oligodendrocytes |
glial cell. in CNS. |
|
schwann cells |
glial cell. in PNS |
|
nodes of Ranvier |
voltage gated Na channels limited to gaps in myelin sheath: __ __ __. depolarization jumps from node to node. |
|
excitatory vs inhibitory postsynaptic potentials |
depolarize membrane a little vs hyperpolarize membrane a little |
|
temporal summation |
series of potentials from same synapse |
|
spatial summation |
potentials from diff. synapse on cell. |
|
inhibitory, excitatory |
__ potentials can cancel our __ potentials |
|
nerve net |
cnidarians have a diffuse __ __ instead of nerves. networks of neurons vary in complexity among the animals. |
|
Central Nervous System peripheral nervous system |
brain+nerve cord running body length. ganglia (cell bodies) and nerves outside CNS |
|
brain |
CNS. where all stimulus and voluntary (and involuntary) behavior is processed. gray on outside |
|
spinal cord |
CNS. carries impulses to and form brain. mediates reflexes both brain and this are made of gray matter (non-myelin) and white matter (myelin) white on outside. |
|
cerebrospinal fluid |
brain and spinal cord filled with this fluid. diffusion of resources and waste. cushion glial cells create tight blood-brain barrier |
|
radial glia |
embryonic glia that form tracks along which newly formed neurons migrate from the neural tube, the structure that gives rise to the CNS |
|
astrocytes |
glia that facilitate info transfer at synapses and sometimes release neurotransmitters; initiates formation of the blood-brain barrier during embryonic development. |
|
radial glia and astrocytes |
__ and __ can act as stem cells, generating new neurons in glia |
|
microglia |
immune cells that protect against pathogens in neurons |
|
ependymal cells |
line ventricles and promote circulation of cerebrospinal fluid |
|
cranial nerves |
connect brain with head |
|
spinal nerves |
connect spinal cord to rest of body |
|
afferent neurons |
bring information to the CNS (sensory) |
|
efferent neurons |
carry information away from CNS motor system autonomic nervous system sympathetic division parasympathetic division enteric division
|
|
motor system |
skeletal muscles; voluntary and reflexes. respond to external stimuli |
|
autonomic nervous system |
smooth and cardiac muscle, glands, etc.; involuntary. sympathetic, parasym, enteric. |
|
sympathetic division |
arousal, "fight or flight" |
|
parasympathetic division |
calming, "rest and digest" |
|
enteric division |
digestion. |
|
brainstem cerebellum
|
hindbrain and midbrain __: midbrain+pons+medulla homeostasis, coordination of movement, sharing info among other brain centers and PNS. attention, alertness, motivation. __: coordinates movement, hand-eye coordination |
|
forebrain |
__: diencephalon: thalamus+hypothalamus+epithalamus. functions in homeostasis, coordination sensory info. circadian rhythms. cerebrum: center for learning, emotion, memory, perception. 80% of brain.outer cortex of gray matter. connected by corpus callosum. |
|
reticular formation |
sleep and arousal are controlled by __ __, diffuse network of neurons in the cor of the brain stem. filters info and determines what reaches cerebellum. |
|
pons and medulla |
__ and __ also regulate sleep. biological clock regulates sleep cycles. |
|
limbic system |
borders the brainstem, responsible for emotions, includes amygdala, hippocampus, and thalamus. |
|
cortex |
__ has 4 lobes: frontal, parietal, occipital, temporal |
|
broca's area |
controls muscles in the face, active during speech generation. |
|
wernicke's area |
active when speech is heard, facilitates comprehension of speech. |
|
lateralization |
two hemisphere's not identical in function. left:math, logic language right: spatial patters, non-verbal thinking |
|
3 processes that determine structure of the nervous system during embryonic development |
1) gene expression, signal transduction 2) huge neuron die-off 3) synapse reconfiguration |
|
long-term potentiation |
ex. of how synaptic connections changed. frequent excitation of a synapse can make the postsynaptic neuron more sensitive to the presynaptic neuron. |
|
different receptors |
chemoreceptors mechanoreceptors photoreceptors
|
|
reception |
1st step of stimulus to brain. sensory cell detects stimulus. stretching of mechanoreceptor opens ion channels |
|
transduction |
2nd step of stimulus to brain. conversion of stimulus to receptor potential. change in magnitude of action potentials is graded: magnitude varies with intensity of stimulus. |
|
transmission |
3rd step of stimulus to brain. if receptor potential initiates action potential. receptor cell: axon or neurotransmitter
|
|
perception |
4th step of stimulus to brain. CNS processing of input from sensory neurons. all perceptions are coded by the paths their action potentials travel. |
|
amplification |
transduction modification. strengthening the stimulus; adding energy. |
|
adaptation |
not to be confused with other adaptation. transduction modification. become unresponsive to constant stimulation. |
|
chemoreceptors |
bind molecules, initieates change in membrane potential. taste, smell.
|
|
mechanoreceptors |
deformed or moved to sense pressure, stretch, motion. touch, hearing, balance.
|
|
electromagnetic receptors |
detect light, electricity, magnetism. eyes to detect light. |
|
thermoreceptors |
detect heat and cold. membrane proteins change shape under diff. temps. |
|
nociceptors |
detect "pain", like extreme pressure, chemicals. highest density in skin. |
|
gustation |
taste; detection of tastants in solution. taste-buds on tongue. |
|
olfaction |
smell; detection of odorants in air. |
|
tympanic membrane |
outer ear "eardrum" vibrates middle ear: 3 tiny bones transmit vibrations
|
|
cochlea |
inner ear. receives vibrations. |
|
vestibular canal |
waves flow down __ __ in ear that cause vibrations that stimulate hair cells. |
|
lateral line system |
mechanoreceptors for detecting low-frequency vibrations perceive the direction and velocity of water, predators, and prey. |
|
statocysts statoliths |
many animals have __ to sense gravity. chamber surrounded by ciliated cells. __ move around as body moves |
|
utricle saccule otoliths |
balance associated with ears. inner ear has __ (horizontal) and __(verticle) chambers lined with hair cells and little stones (otoliths) |
|
rods and cones |
__ and __ change light energy into chemical energy, which is transmitted to the brain. |
|
rhodopsin |
visual pigment in rods. active __ leads to signal transduction
|
|
ganglion cell |
axons receive info from rods and cones, and form the optic nerves that transmit impulses to the brain. |
|
sarcomere |
basic contractile unit of myofibril (made of actin and myosin filaments) |
|
z lines |
sarcomere. ends of actin fibers line up at ends called __ __. |
|
m line |
sarcomere. middle of myosin fibers lined up called __ __. |
|
tropomyosin troponin complex |
two sets of regulatory proteins are bound to the thin (actin) filaments. Ca2 and regulatory proteins. __: coils around actin __: arranged along tropomyosin. Ca2 in cytoplasm binds this, results in exposure of myosin binding sites.
proteins block myosin binding sites.
|
|
motor unit |
___: all fibers controlled by one neuron. all contract together.
one muscle may be controlled by hundreds of neurons |
|
fixed action patterns |
sequence of unlearned acts linked to a simple stimulus. |
|
communication |
the transmission and reception of signals btw animals |
|
innate behavior |
traits that are fixed by genotype. individuals with the same genotype can have diff behavioral phenotypes.
learning: modifying behavior based upon experience |
|
imprinting |
formation at a specific stage in life of a long-lasting behavioral response to an individual or object, includes a sensitive, critical, period.
necessary for bonding btw parents and offspring. |
|
how to determine magnitude of environmental effects. |
1) behavior the result of complex interactions of environment and genotype 2)raise the same/similar genotypes in diff environs. |
|
cross-fostering studies |
offspring of one species raised by another. same/similar genotypes in diff environs. |
|
twin studies |
look at identical twins placed with diff foster families. useful for demonstrating effects of environment on identical genotypes. |
|
associative learning |
associate one stimulus with another. ex: classical conditioning, operant conditioning. |
|
classical conditioning |
arbitrary stimulus leads to certain response. ex: Pavlov's dog and bell |
|
operant conditioning |
trial and error learning. ex: rat obtaining food |
|
spatial learning |
maintaining an internal "map" ex: digger wasps use visible landmarks to find nest |
|
cognition |
reasoning, awareness. ex: honybees can be trained to recognize "same" and "diff" colors in maze experiments |
|
problem-solving |
devising solutions to proceed past obstacles. ex: the raven and the string. social learning: many animals can learn by observing conspecifics. |
|
3 ex. of expectations of natural selection to refine behaviors to maximize survival and reproduction. |
optimal foraging mate choice and parental care sexual selection
|
|
optimal foraging |
maximize benefit, minimize cost. ex: fruit fly larval foraging: rovers and sitters have different foraging alleles.
|
|
mating system |
__ __'s are related to the parental roles. length and # of relationships btw males and females. diff species, different ways. |
|
monogamous |
mating type. long-term pair bonding |
|
polygamous |
mating type. multiple mates. polygyny: one male, multiple females polyandry: one femal, multiple males (uncommon) |
|
promiscuous |
mating type. no pair-bonding. |
|
sexual selection |
__ __ has behavioral effects. a type of natural selection; result of differential mating success when there is competition for mates.
Males compete to attract females (sing, dance)
males physically compete. ex: sheep. |
|
sexual dimorphism |
sexual selection leads to __ __ in phenotypic traits: appearance and behavior |
|
altruism |
__ presents a problem for evolutionary theory. it means to do something that lowers your own fitness but increases fitness of other individuals. ex: squirrel gives alarm call when sees predator. group gets a warning, caller attracts the predator....nonreproductive mole rats take care of reproductive ones |
|
genes |
in parent-offspring relationship, parent is actually looking after their __. the fitness of the child, affects fitness of parent. |
|
inclusive fitness |
this idea solves the problem of altruism in evolutionary theory. fitness (representation of your genes in the next generation) depends on your reproduction and that of your close relatives. |
|
Hamilton's Rule |
rB>C weigh the cost/benefit of an "altruistic"act C(cost) is the # of offspring that an action might cost the "altruist" B(benefit) is the # of offspring that an action will gain the recipient r (coeff. of relatedness): average # of genes shared by the 2. as long as rB>C, then the benefit outweighs the cost. |
|
the ways organisms interact with other organisms and their environments on diff scales are |
individual, populations, communities, ecosystems, landscapes, global. |
|
populations communities ecosystems landscapes global |
__: groups of the individuals of the same species __: groups of pops __: groups of communities __: groups of ecosystems __: the Earth: biosphere |
|
evolutionary time |
populations change to adapt to their environments. |
|
ecological time |
response of organisms, populations, etc. to their environments. |
|
ecology vs environmentalism |
science vs advocacy. |
|
dispersal |
movement of individuals to new areas. barriers can explain species distributions. ex: no kangaroos in NA even though they could survive there. |
|
habitat selection |
when animals choose to avoid a livable habitat: psychological barrier. ex: antbirds won't fly across water ever. |
|
biotic factors |
species distributions are often limited by other species, which is termed __ __.
species absent because other species are absent/present
herbivore can limit distribution of food species: sea urchins and kelp
|
|
physiological tolerance |
species distributions are also limited by their __ __. physical/chemical properties= ABIOTIC FACTORS. |
|
abiotic factors |
physical/chemical properties=__ __.
temp: too hot, too cold water: too wet, too dry sunlight: too much or little geology: inorganic parts of habitat (minerals, rocks, physical structure of land, pH) |
|
abiotic factors biotic factors. |
Earth is not homogeneous for __ __:
leads to variation in __ __, etc. many abiotic factors can be summarized as CLIMATE. |
|
surface curved |
results in broad climates. areas away from equator get less intense sunlight. |
|
axis of rotation tilted 23.5 |
results in broad climates. seasonal variation in sunlight. |
|
pattern of heating/evaporation |
results in broad climates. variation in precipitation |
|
rotation of the Earth |
results in broad climates. circulation of air/water currents. |
|
local variations |
proximity to water: moderates temps and humitiy
mountains (shadow to sunlight, altitude, temp, rain shadow)
tilt of earth results in predictable seasonality: leads to variation in day length, sunlight, temp. |
|
long-term global variation in climate |
some periods are warmer/cooler/wetter/drier than others.
until 15-20000ya: northern latitudes coverd by glaciers.
species continue to move north (away from equator) as global climate continues to warm. |
|
characteristic biomes |
biotic and abiotic factors combine to create __ __. |
|
biomes |
major habitat types, determined by both biotic and abiotic factors. |
|
ecotones |
areas of transition btw biomes |
|
disturbance |
__ leads to community variation, patchiness. ex: fire, hurricanes. |
|
salinity and depth |
Aquatic biomes are characterized by __ and __. there are several aquatic biomes since 75% earth surface is aquatic.
freshwater vs marine pelagic(open water) vs benthic(bottom) |
|
photic vs aphotic |
most photosynthesis occurs near the surface. light filtered out quickly: __ vs __. |
|
population |
chance over time. conspecific individuals occurring in a particular area. live in same environ. use same resources interact/breed with each other. |
|
populations |
__ are dynamic: changing
gain individs from births gain individs from immigration lose individs from deaths lose individs from emigration |
|
3 characteristics to describe populations |
density: # of invids per unit area (or volume) mark recapture method. dispersion clumped uniform random demographics: age and sex structure of the pop. |
|
life table |
age specific summaries of survival in population. usually divided by sex. useful way to summarize population demography.
constructed by following a single COHORT from birth to death. |
|
surivorship curves |
__ __ are a graphical way to summarize population demography. number alive plotted vs each age.
|
|
life history |
species have characteristic survivorship curves, depending on the __ __: pattern of reproduction and survival.
Type 1: put energy into caring for a few offspring (humans) Type 3: high death rates early on, low for survivors (oysters) Type 2: beldings gournd squirrel. many relatively small offspring. |
|
reproductive tabel=fertility schedule |
rates of birth are just as imp as rates of death. generally pay attention only to females in pop. follow reproductive output of cohort
|
|
cost of reproduction |
energy spent on offspring not spent on parent. |
|
iteroparity |
repeated reproduction. multiple reproductive periods. ex: belding's ground squirrel. variation in life history |
|
semelparity |
big-bang reproduction: all reproduction concentrated in a single effort. favored in unpredictable environs: low probability of adult survival. variation in life histories. |
|
trade offs |
cant maximize all reproductive patterns at same time. more offspring means smaller offspring with less care. variation in life histories. |
|
change in pop |
__ __ __= births during time interval+deaths during time interval. (ignore migration). |
|
exponential pop growth |
this model is unrealistic in most circumstances. |
|
feeback |
population growth is often regulated with __.
|
|
carrying capacity |
# of individs that a habitat can sustain. limiting factors such as energy, shelter, nutrients, territories, water. can vary over time limiting resources can lower b, raise d. |
|
logistic pop growth |
this model incorporates carrying capacity. characteristic S shaped curve. |
|
K-selection |
way to talk about life history trade-offs. for traits that are helpful at high densities. few relatively large offspring. (type 1 survivorship curve). |
|
r-selection |
way to talk about life history trade-offs. for traits that are helpful at low densities. many relatively small offspring; (type 2 survivorship curve). |
|
density dependent |
__ __ is ecological feedback. when birth or death rates change with pop size, they are this. too small, grows. too large, shrinks |
|
causes of density-dependent regulation |
competition disease predation accumulation of wastes intrinsic factors (physiological responses to crowding)(stress hormones that lower reproductive rate). |
|
density-independent |
change in population size from factors independent of density is __ __ regulation. ex: weather events (drought, tornado, etc.) |
|
dynamic |
population size is __. pops fluctuate over time. predation: increase in hares leads to increase in lynx; overexploitation by predators leads to low prey densities. |
|
space |
pops vary in __ as well as time. we have been focusing on r, not migration. |
|
metapopulation |
populations connected by dispersal in a __. sources: positive pop growth, lots of emigration to sinks. sinks: negative pop growth, lots of immigration from sources required to maintain pop.
pops blink in and out over space and time in a mosaic. |
|
metapopulation |
habitat fragmentation can yield a __ from what originally was a large continuous pop.
some species occur naturally in this structure : butterflies. |
|
the ways in which species interact within communities |
1)competition: -/- 2)predation: +/- one animal eats another cryptic coloration=camouflage aposematic coloration=brightly colored, warning batesian mimicry: harmless resembling venomous animal mullerian mimicry: 2 venomous resembling each other. 3)herbivory: special case of predation; animal east a plant/alga. |
|
niche |
competition results from species having overlapping __. sum of the biotic and abiotic needs of a species; its place/role in a habitat. |
|
outcomes of overlapping niches causing comp. |
competitive exclusion: weaker competitor eliminated from local area.
resource partitioning: species "realized niche" smaller than "fundamental niche" (2 barnacles competing for space).
character displacement:resource partitioning leads to morphological differences |
|
symbiosis |
relationship where close association btw species pairs, where at least one species always benefits. mutualism commensalism parasitism |
|
richness and abundance |
__ and __ are both aspects of community diversity. |
|
species richness |
number of different species |
|
relative abundance |
proportion of individuals that belongs to each species
|
|
shannon diversity index |
two communities can have same richness but different structures. ex: __ __ __. |
|
trophic structure |
feeding relationships among species. energy moves up from lower levels.
food chain: producers (plants) consumers(herbivores) consumers(carnivores) |
|
food web |
best way to show a trophic structure. multiple connections among levels. species occur at multiple levels. most have 6 or less levels. |
|
energetic hypothesis |
inefficiency of energy transfer btw levels in food web. |
|
dominant species |
most abundant or greates biomass(total mass of entire pop). determine existence of other species. |
|
keystone species |
key niches maintaining community structure; not necessarily dominant. ex: w/out starfish, mussels would take over. |
|
facilitators |
"ecosystem engineers". ex: beavers create habitat. |
|
communities |
__ have both top-down and bottom-up regulation. p-->h p<--h p<-->h |
|
bottom-up model |
p-->h-->c increasing p, increases h, which increases c
|
|
top-down model |
p<--h<--c trophic cascade. |
|
disturbance |
species richness is maintained by __. |
|
stable equilibrium |
most communities are not in a __ __, that is they are not static entities. |
|
nonequilibrium model |
better characterizes most communities, they are dynamic with shifts in the incidence and relative abundance of species over time. |
|
intermediate disturbance hypothesis |
some disturbance increases species diversity. low disturbance= dominant species exclude others high disturbance=high stress; slow-growing intermediate disturbance=allows for a mix; creates patches of diff habitats |
|
succession |
within communities, there is a characteristic pattern of species replacement over time: __. |
|
primary succession |
beginning without soil. ex: after a volcanic eruption, glacier recession. |
|
secondary succession |
with soil; ex: fire burns forest. takes less time. |
|
species-area curve |
larger areas have more species:seen in __ __ __. larger area, more habitats, support more diff species. |
|
latitudinal gradient |
more species closer to the equator; higher tropical diversity. historical: poles recently glaciated climate: warmer, wetter, so higher productivity (evaptranspiration=evaporation+transpiration) |
|
ecosystem |
sum of biotic and abiotic interactions in an area. ranges from microhabitat to whole earth. 2 abiotic processes central to ecology: flow of energy and cycling of nutrients |
|
flow of energy |
energy (usually sunlight) transformed to chemical energy by autotrophs, all eventually lost as heat |
|
cycling of nutrients |
elements continually recycles; move btw ecosystems. inputs: minerals from dust and rainwater outputs: gases lost to atmosphere water
generally in/outputs small relative to amount recycled |
|
trophic levels in ecosystem |
primary producers=autotrophs. plants primary consumers=herbivores that eat producers secondary consumers=carnivores that eat herbivores tertiary consumers=carnivores that eat carnivores detritivores/decomposers=get energy from detritus(nonliving animal) |
|
primary production |
production is ultimately limited by the amount of energy that enters the system. __ __: amount of light energy converted to chemical energy in a given span of time. |
|
gross primary production (GPP) |
total 1degree production for an ecosystem |
|
net primary production (NPP) |
part stored as organic matter. this is the energy available to higher trophic leves
|
|
secondary production |
new biomass added to consumers; amount of 1degree production converted to consumer. |
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% production efficiency |
=portion of assimilated 1degree production that is used for growth. endotherms have low efficiency ectotherms have high |
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trophic efficiency |
percent production transferred up to the next level. can express pyramid of net production. |
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biomass pyramid standing crop |
can also think of __ of __ (not production) |
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limiting nutrients |
if adding a nutrient increases productivity, then it is limiting.
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eutrophication |
increased algal production due to pollution (sewage, fertilizer) |
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biogeochemical cycles |
both abiotic and biotic. inputs/outputs. nutrients sometimes present but unavailable.
nutrients cycle through ecosystems. most imp: H2O, C, N, P |
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temperature |
___ affects leaf litter decomposition rates. ex: case study from Canadian ecosystems |
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hubbard Brook study |
cut down all the trees in the valley, noticed massive loss of nutrients by the ecosystem. lesson: standing plants control outputs. these long term studies are needed to understand the natural functioning of ecosystems.
humans have conducted accidental experiments: changed the biotic and abiotic interactions in ecosystems, resulting in altered function. |
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nitrogen cycle |
humans enrich the __ __ in agriculture.
farming removes N from soil. temperate grass land: lots of soil/N that lasts decades tropical forest: little soil/N lasts few years. crops grown: N removed. ends up in sewer. |
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critical load |
excess (amount that exceeds __ __, no longer limiting) runs off into rivers. extra N leads to algae blooms in gulf of mexico, which leads to O2 depletion: "dead zone" can be mitigated by using less fertilizer. |
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global human population size |
the human population growth is still a positive growth but is no long exponential |
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annual percent increase |
this percentage has decreased throughout the years. |
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human population growth in diff countries |
human pop growth and age structure varies by country depending on whether they are industrialized or developing. graph shows that the less developed countries have a higher birth rate, but higher death rate as well. developed countries, have a lower birth rate and maintain that rate throughout different ages. |
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demographic transition |
switch from high birth and death rates to low birth and death rates in a given country, tends to accompany industrialization and improved living conditions. undeveloped countries (aphighanistan) has rapid growth, US has slow growth, and italy has no growth. the chart for italy shows that the there are the most people in the middle age age range. |
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ecological footprint |
this measures human impact. calculates how much land and water resources we consume to grow food, support lifestyles, and assimilate waste; can also be measured as energy consumption. measured per capita. |
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conservation of biology |
the goal of this is to conserve biodiversity, and mitigate negative effects of humans on ecosystems. |
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anthropogenic |
human caused. ecosystem modification is causing increased extinction rates. always extinction but more species going recently. |
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why worry about biodiversity |
innate tie to nature: biophilia obligation to future generations provide us with useful services: ecosystem services (clean, detoxify waste, pollinate crops) |
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conservation biologists |
they are concerned with loss of biodiversity at multiple levels.
Endangered Species Act. 12% birds endangered worldwide 21% mammals 730 plant species extinction of freshwater animals. 5x worse than terrestrial.
preservation of species genetic diversity community and ecosystem diversity |
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community and ecosystem diversity |
fates of species interconnected. flying foxes hunted, but important pollinators and seed dispersers. protect habitats |
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threats to biodiversity |
1) Habitat loss and destruction biggest threat. 2) Introduced/Exotic Species increase in global travel led to this. 3) overexploitation fisheries and large mammals. harvested ^ than can reproduce. hunting of elephants, rhinos, whales. 4) global change acid rain, climate change, atmospheric chemistry. |
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human activities that cause habitat degradation and loss |
agriculture= primary cause of ecosystem change natural resource extraction= mining, logging, fishing urbanization and infrastructure development war and violent conflict pollution |
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consequences of pollution besides degradation |
toxins accumulate in top predators. humans add synthetic chemicals to ecosystem like pesticides (DDT), industrial chemicals (PCBs), which are not broken down by detritivores. mercury from plastic manufacture, coal burning. accumulates in predators, especially fishes. |
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biological magnification |
becomes more concentrated in higher trophic levels. |
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consequences of pollution |
DDT (insecticide), now banned. accumulated in birds of prey, like bald eagles. led to weak egg shells.
still use DDT in Africa for malaria. |
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invasive species |
an introduced species that establishes, expands its range, and has a substantial impact on native organisms and ecosystems. ex: fire ants. |
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invasive species can interact with natives in many ways |
as competitors, predators, and parasites. predators: ex., brown tree snake on Guams 9 of the island's 11 native forest dwelling bird species are now extirpated (extinct on Guam). these snakes have even caused electrical outages in Guam bc they coil around the power lines and break them. |
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overexploitation |
hunting fishing collecting for trade. leads to decrease in species abundance and ultimately extinction of the species. |
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fossil fuels |
burning __ __ creates acid rain. burning them release S and N. combines with water to make sulfuric and nitric acid.lowers pH of water bodies in areas with weakly buffered water (less bicarbonate to neutralize it) |
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chemicals |
__ we release can also alter abiotic factors. CFCs used in refrigeration, air conditioners. the layer of ozone in the atmosphere absorbs UV radiation bc CL released reacts with ozone. "hole" in ozone. mitigated by banning the production of CFCs in 1987. has helped a lot. |
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excess CO2 |
this excess in the atmosphere from burning fossil fuels results in increasing global temps. greenhouse effect. the global warming trend on Earth has had greatest effect at high latitudes. |
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extinction vortex |
small populations lead to smaller populations which leads to extinction. |
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minimum viable population (MVP) size |
number of individuals at which a species is able to sustain its numbers and not enter the extinction vortex. depends on the species. |
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effective population size |
# in pop. that breed. demographic modeling to predict how long population can last. |
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landscapes and habitats |
often more efficient to focus of __ and __ than on species. this way we can protect areas instead of multiple species. set aside large tracts of land to protect from fragmentation. (edges, edge effects, corridors) |
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edges |
boundaries btw communities are ecosystems |
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edge effects |
increase due to habitat fragmentation |
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corridors |
strips of habitat that connect otherwise isolated habitat fragments, facilitates movement and dispersal. |
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biodiversity hot spots |
smaller areas with lots of diversity |
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restoration ecology |
we need to restore when ecosystems are too far degraded= __ __. ex: turning open-pit mine into salt marsh. |
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bioremediation |
using plants, fungi, prokaryotes, etc. to detoxify an area. plant plants that can take up contaminants in contaminated areas. also use bacteria |
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biological augmentation |
use organisms to add compounds to ecosystem. ex: plant legumes to increase N in soils until native plants get established. |
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zoned reserves |
have surround by "buffers" that separate. protected areas with areas set aside for regulated human pop, limited logging. (in Costa Rica). |