Which is a phenomenon that can result from directional selection? a. There is an increase in the number of different breeds of dog. b. There is an increase in the number of giraffes with long necks in areas of Africa where low-growing trees have died. c. There is an increase in garter snakes with different coloration patterns found in backyard gardens.

B) There is an increase in the number of giraffes with long necks in areas of Africa where low-growing trees have died

Explanation:

The directional selection is one of the ways of the natural selection in which the natural selection selects or favours the most extreme trait of the species and the extreme trait show higher fitness than the normal or average trait.

In the given question, the case of Giraffe necks shows directional selection as the normal length of the neck is not favoured by the environment but the extreme trait that is long neck is favoured by the environment and the selection shifted to that level.

Thus, Option-B is the correct answer.

the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity

helicase, i think thats it