Why does an action potential only move in one direction?

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

What is the relationship between absorbance of light and the rate of photosynthesis?

Plz ! cattle ranchers and dairy farmers rarely allow all of their animals to reproduce instead they practice selective breeding and only encourage the reproduction of animals with specific features. which of the following cows would a dairy farm most likely choose to reproduce? a. a cow that makes a lot of milk. b. a cow that can run quickly. c. a cow with a think, soft fur. d. a cow with large, strong hooves.