New genetic traits upon which natural selection can act usually arise from
A)mutations and crossover.
B)increases in cell size and shape.
C)the need to become adapted to a new environment.
D)the demands of the environment.

Question

Quizplus · Accepted Answer

New genetic traits usually arise from mutations and crossover during the process of DNA replication and cell division. These mutations can lead to changes in the DNA sequence, resulting in new traits or variations that may be advantageous or disadvantageous, upon which natural selection can act. Increases in cell size and changes in shape are not genetic changes and therefore, do not result in new traits. While adaptations to a new environment may result in the selection of existing traits, they do not create new ones. Similarly, the demands of the environment may select for existing traits but do not create new ones.

New Genetic Traits Upon Which Natural Selection Can Act Usually