What is a homologous features/structure?

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

Which animal is a producer in this ecosystem

Based on her survey, which advertising mediums will work best to publicize leslie's in-store specials?