Answer:
Darwin used multiple lines of evidence to support his theory of evolution by natural selection -- fossil evidence, biogeographical evidence, and anatomical evidence.
Explanation:
Answer: reproductive cells are haploid
Explanation: mammals are diploid. In sexual reproduction each paren contributes a haploid set, which is what each reproductive cell
Lets say the plant that formed nodules is Species A, and the one who didn't is Species B.
If the nitrogen is concentrated in one area but at a low concentration, then Species A may have formed nodules because it is closer to the concentrated nitrogen. Species B didn't because the nitrogen that is active is being taken by Species A.