A population of finches experiences a drought where all of the normal food types disappear leaving only ant hills that certain finches with thin beaks can access. Over time, almost all of the population has a similar long sharp beak. This is an example of:

This question lacks options; the options are:

A) Artificial selection

B) Stabilizing selection

C) Disruptive selection

D) Directional selection

The answer is D) Directional selection

Explanation:

Changes in the environmenal condition affects the distribution of organisms phenotypes. Via this change, organisms with certain traits are naturally selected. The types of natural selection are; stabilizing, disruptive and directional.

Based on the description of the selection in this question, the type of selection is DIRECTIONAL. Directional mutation is that in which one of the two extreme phenotypes in a population is selected against while the other is favored by the occurrence of a natural environmental hazard. The distribution gradually shifts to favour one extreme over the other until the other unselected extreme gets extincted.

This is the case regarding a population of finches affected by drought caused by flood causing all their food source to disappear leaving only ant hills that certain finches with thin beaks can access. This environmental change favorably selects one extreme phenotype (finches with long thin beaks). Hence, a type of DIRECTIONAL selection

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.