You have a yellow pea, but you do not know if it is heterozygous (Yy) or homozygous. When you perform a test cross to a green recessive pea (yy), you observe that half the offspring have yellow peas and half have green peas. What can you conclude?

a. The original, parental yellow pea plant was homozygous (YY).
b. The original, parental yellow pea plant was heterozygous (Yy).
c. Half of the yellow pea offspring are heterozygous (Yy).
d. All the yellow pea offspring are homozygous (YY).

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Read the following scenario to answer the following question. over the past 60 years, many amphibian species have experienced significant population declines, and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. when most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that a. the founder effect becomes increasingly important b. microevolution no longer occurs c. gene flow between populations is reduced d. artificial selection becomes a greater factor in microevolution

What two fields of study provide the core information that is used to classify organisms?