Actin, a protein found in almost all eukaryotic cells, is expressed in most cell types at a fairly constant level. Thus, the gene that codes for actin can be considered a(n) gene.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

Diagram of the evolution of land plants?

How does the nervous system affect the excretory system?