Question

Which statement is true about how phenotypic changes occur in a species in a variable environment?

A. The genotype must change in order for a phenotype to change.

B. The genotype does not have to change in order for the phenotype to change.

C. The genotype must change through mutation in order for the phenotype to change.

D. In order for a phenotype to change in a species, there must be very little genetic variation in the population.

Answer 1

The correct statement is that the genotype does not have to change for the phenotype to change, as environmental factors can lead to phenotypic variations without genetic alterations. Phenotypic variations also allow species to adapt to changing environments through natural selection.

Step-by-step explanation:

Which statement is true about how phenotypic changes occur in a species in a variable environment? The correct answer is B: The genotype does not have to change in order for the phenotype to change. While it is true that changes in genotype can result in changes in phenotype, phenotypes are also influenced by environmental factors. These environmental factors can cause phenotypic changes without altering the genetic makeup. For example, in some reptiles, sex is determined through temperature-dependent sex determination (TSD), where the incubation temperature can result in the development of males at one temperature range and females at another, all without genetic changes.

Moreover, a population's genetic variation plays a crucial role in its ability to adapt to changing environments. Phenotypic variation can shift due to natural selection where individuals best-suited to the environment more likely survive and reproduce, passing on their genes. Yet, this adaptation can occur without requiring mutations; simply the presence of genetic variability and environmental pressures can drive changes in phenotypic distribution.