Question

how often a coin will land on \heads\ when flipped is 0.5.
natural selection
variation
genetic drift
evolution
frequency
gene flow

Explanation:

The question is about identifying the term that matches the description of how often a coin lands on "heads" (0.5). "Frequency" refers to how often something occurs, which fits the description of the probability (or frequency) of a coin landing on heads. Natural selection, variation, genetic drift, evolution, and gene flow are concepts related to biology/evolution and do not relate to the frequency of a coin flip outcome.

Answer:

frequency