Which of these is the smallest unit upon which natural selection directly acts?

Question

Quizplus · Accepted Answer

Natural selection acts directly on an individual's phenotype, which is the physical expression of their genotype. In other words, it is the observable trait or characteristic of an individual that influences their ability to survive and reproduce. The other options (A-C) refer to gene frequency at larger scales, and (D) refers to the specific genetic makeup of an individual, which can influence their phenotype but is not directly acted upon by natural selection.

Which of These Is the Smallest Unit Upon Which Natural