Question

Frequencies of inversions and/or allele frequencies often vary regularly when examined over a geographic area changing in either latitude or climate. This type of regular change is called a ________.

1) cline

2) gradient

3) zonality

4) biome

Answer 1

A regular change in allele frequencies or phenotypic variation across geographic areas of differing climates or latitudes is called a cline.

Step-by-step explanation:

A cline represents a systematic and regular change in allele frequencies or phenotypic variation across a geographic area, typically associated with variations in latitude or climate. This phenomenon is a form of geographic variation where populations of a species exhibit gradual changes along an ecological gradient.

An illustrative example of a cline is the latitudinal cline observed in endothermic animals. In this scenario, the size of these animals tends to increase in cooler climates closer to the Earth's poles, reflecting adaptations to temperature variations. Additionally, altitudinal clines can be observed in flowering plants, where different blooming times are exhibited along a mountain slope in response to changes in altitude.

Clines provide valuable insights into how species adapt to diverse environmental conditions, emphasizing the role of natural selection in shaping the genetic and phenotypic characteristics of populations across geographical gradients.