If you decide to buy a purebred puppy, you would have many different dog breeds to choose from. the wide variety of dog breeds is the result of hundreds of years of
a) random mating.
b) gene sequencing.
c) selective breeding.
d) genetic engineering.

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. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Which of the following is a common danger of commercial fishing?

During a fierce storm a large number of tall trees on an island are uprooted by the wind and die. most of the trees on the island are now short trees and produce seeds that grow into short trees. what concept is shown in this example? question 5 options: natural selection artificial selection genetic engineering gene splicing