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53 Cards in this Set
- Front
- Back
What are the majority of sugars synthesised by plants used for |
respiratory substances |
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What are the sugars synthesised by plants that aren't used in respiration used for |
biological molecules which make up the biomass of the plants |
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name the two ways biomass can be measured |
mass of carbon or dry mass of tissue per given area |
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what is the name of the piece of equipment that can be used to measure the chemical energy stored in the dry biomass |
a calorimeter |
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what is Gross Primary Production |
the chemical energy store in a given area or volume of plant biomass |
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what is Net Primary Production |
the chemical energy store in plant biomass after respiratory losses have been taken into account |
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what is the equation for Net Primary Production |
NPP = GPP - R |
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what is a trophic level |
a level within an ecosystem hierarchy |
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what are the three uses of NPP |
Plant growth Reproduction decomposers |
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What is the equation for net production of consumers |
N = I - (F + R) |
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How is primary and secondary productivity measured |
biomass in a given area in a given time |
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What is the role of saprobionts |
obtain nutrients from dead organic matter and animal waste using extracellular digestion |
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How does Mycorrhizae relationships work |
the fungi greatly increases the surface area of the roots so more ions are absorbed, also the amount of water absorbed is increased. |
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What is ammonification |
when nitrogen compounds form dead organisms are turned into ammonia by saprobionts |
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what is nitrification |
the process of ammonia ions in the soil being changed into nitrates. Ammonia ions, nitrites, nitrates |
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What is nitrogen fixation |
when nitrogen gas is turned into nitrogen containing compounds. nitrogen fixing bacteria on the plant convert nitrogen into ammonia |
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What is denitrification |
When nitrates in the soil are converted into nitrogen gas by denitrifying bacteria |
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What is the genotype |
its genetic constitution |
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What is a phenotype |
the characteristics of an organism as a result of its genes |
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What does a dominant allele mean |
A dominant allele is always expressed in the phenotype |
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What does codominance mean |
two alleles are expressed in the phenotype as neither are recessive |
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What does homozygous at that locus mean |
both chromosome have the same allele at a particular loci |
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What is monohybrid inheritance |
the inheritance of a characteristics of a single gene |
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Draw the genetic diagram for NN cross nn |
. |
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What is a dihybrid cross |
the inheritance of two different characteristics controlled by two different genes |
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Draw a punnett square for RrYy x RrYy |
. |
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draw the genetic diagram representing gender |
. |
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Why are men more likely to suffer from recessive alleles affecting sex linked genes
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Males only have one X chromosome and so the allele is always expressed even if faulty |
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what is an Autosome |
A chromosome which isn't a sex chromosome |
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Genes on the same chromosome are said to be linked, what makes a strong link |
the closer the genes the more closely linked they are |
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What are recessive epistatic alleles |
When two copies of there allele will block the expression of the other gene |
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What is a Dominant epistatic allele |
When having at least one of the alleles mean the expression of the other gene is blocked |
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What is the Chi-squared test |
a stats test used to see if the results of an experiment support a theory |
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What probability that the results are due to chance only is commonly accepted by biologists |
0.05 |
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What is a species |
A group of similar organisms that can reproduce to give fertile offspring |
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What is a population |
a group of organisms of the same species living in a particular area at a particular time |
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What is a gene pool |
the complete range of alleles present in a population |
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What is the Hardy-Weinburg principle |
a mathematical model that predicts the frequencies of alleles in a population wont change from one population to the next |
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What conditions is the Hardy-Weinburg principle only true under |
A large population no immigration, emigration, mutations or natural selection random mating |
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What can the Hardy-Weinbrug principle be used for |
test whether selection or any other factors are influencing allele frequencies |
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What is the equation |
p2 + 2pq + q2 = 1 |
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What does infraspecific variation mean |
individuals within a phenotype show a variety of of different phenotypes |
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What is the main cause of genetic variation |
different alleles |
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Apart from through mutation what else causes genetic variation |
meiosis and the random fertilisation of gametes during sexual reproduction |
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What is natural selection |
Where an allele becomes more common in a population because it codes for a characteristic that makes an organism more likely to survive reproduce and pass on its offspring |
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what is stabilising selection |
where individuals with alleles for characteristics towards the middle of the range are more likely to survive and reproduce. It occurs when the environment isn't changing |
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what is directional selection |
where individuals with alleles for a single extreme phenotype are more likely to survive and reproduce. |
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what is disruptive selection |
where individuals with allele for extreme phenotypes are more likely to survive and reproduce |
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what is the affect of evolution on the gene pool |
the frequency of different alleles changes |
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what is allopatric speciation |
when populations become separated geographically an these two environments have different conditions |
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what is sympatric speciation |
when random mutations within a population cause reproductive isolation |
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What is Genetic drift |
the change over time in allele frequency due to chance which dictates allele inheritance |
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Why is genetic drift only important in small populations |
in larger populations the chance factor is evened out across the whole population |