“Genes and environmental effects are often part of the explanation. “
“...disease-causing alleles of one gene may be suppressed by alleles of another gene elsewhere in the genome, or a person's overall health may influence the strength of a disease phenotype.”
https://www.khanacademy.org/science/high-school-biology/hs-classical-genetics/hs-non-mendelian-inheritance/a/polygenic-inheritance-and-environmental-effects
Answer is A.
Archaea requires neither sunlight for photosynthesis as do plants, nor oxygen. Archaea absorbs CO2, N2, or H2S and gives off methane gas as a waste product the same way humans breathe in oxygen and breathe out carbon dioxide. An example is chemosynthetic bacteria by sea drifts. They use chemical energy to produce vital processes to live.
When limiting factors increase, diversity in populations decreases. In this sense "limiting factors" can be anything from a lack of resources to a lack of food, meaning it's harder for the population to survive.
1.) everything that can be observed or explained scientifically. - natural phenomenon
2.) a well-supported explanation of all the evidence related to a natural phenomenon. - Theory
3.) the procedure of scientific inquiry used to investigate natural phenomena. -scientific method
glucose would be the answer because glucose is basically sugar