Two theories together account for color vision. in stage one, the helmholtz trichromatic theory shows that the eye contains while in stage two, hering's theory accounts for the nervous system's which are activated by one color light, and inhibited by the opposite color light.

Rank the three variables in terms of how strongly they affect the "species" composition of the bacterial communities. place the variable with the weakest effect on the left and the variable with the strongest effect on the right.

Why did mendel use pea plants in his experiments? a. they have no alleles. b. they are haploid organisms. c. they reproduce quickly. d. they are all male.

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food