Speciation can be driven by evolution, which is a process that results in the accumulation of many small genetic changes called mutations in a population over a long period of time.
There are a number of different mechanisms that may drive speciation.
Two of them to point out here.
1. natural selection
2. genetic drift
genetic drift describes random fluctuations in allele frequencies in populations, which can eventually cause a population of organisms to be genetically distinct from its original population and result in the formation of a new species.
c.The products of photosynthesis are the reactants of respiration.
Explanation:
Photosynthesis and Respiration can be thought of as opposites. Photosynthesis is taking in CO2 and energy and releasing O2, while Respiration is taking in O2 and energy to release CO2.
The only independent variable in this experiment is the amount of nitrogen Sarah uses. All of the other variables are dependent on other factor and processes, but Sarah controls the amount of nitrogen that she uses for each plant.