6.) Natural selection is the process that determines which individuals within a species will reproduce and pass their genes to the next generation. Genes that are advantageous are more likely to be passed on. Death is part of the process of natural selection, species which fail die. The number of offspring, pass on the beneficial genes to the organism.
13.) Parasitism, mutualism and commensalism all have something in common; they all involve 2 species. As stated on page 91, “symbiosis is a close, long-lasting, physical relationship between two different species.” In parasitism, the parasite lives in another organism, known as the host and uses it’s nutrients. Commensalism, is when one organism is not affected while the other organism has benefits. Lastly, Mutualism is a symbiotic relationship and is beneficial to both species.
20.) During photosynthesis, carbon dioxide is formed hydrogen to …show more content…
Burning fossil fuels release nitric oxide which combine with other elements to form acid rain and also smog. Fertilizers put my nitrogen into the soil, which in the end add more nitrogen to the cycle. Lastly, deforestation is an issue because the nitrates in the soil can’t be absorbed by any plants.
24.) Phosphorous compounds are released by the erosion of rock and becoming dissolved in water. Producers (plants) use the dissolved phosphorous compounds to build the molecules they need. The consumer (animals) obtain the phosphorus they need when they eat plants of animals. Waste products of animals have significant amounts of phosphorous which can be used as a fertilizer. Lastly, when organisms die they excrete waste products which the decomposers recycle the phosphorus compounds back into the soil. Respiration is used by animals giving off C02 from