Which mechanism(s) are responsible for introducing new alleles into a population's gene pool? a) gene flow b) emigration c) niche shift d) natural selection

The right answer is -

A) Gene flow

Explanation:

Gene flow is a process of gene migration or the transfer of gene variant (also called allele, which is responsible for genetic variation in population) from one population to another population.

As a consequence of gene migration, new alleles are introduced or added in the already existing population, thereby increasing genetic diversity.

Thus, option A) is the right answer.

"a scientist studying a whale and its surroundings would need to understand the structure of atoms in case something was negatively affecting the whale or its surroundings."

explanation:

this was from the link provided:

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.