[Campbell Biology P.549] Which of the following best defines balancing selection? | Practice Question
Which of the following best defines balancing selection?
A: A type of natural selection that maintains two or more phenotypic forms in a population.
B: Selection that eliminates all unfavorable alleles from a population.
C: Selection that leads to a continuous shift in allele frequencies towards one extreme.
D: Selection that only occurs when heterozygous individuals have the lowest fitness.
D: Selection that only occurs when heterozygous individuals have the lowest fitness.
Explanation
The text defines balancing selection as a process that 'may preserve variation at some loci, thus maintaining two or more phenotypic forms in a population. Known as balancing selection, this type of selection includes frequency-dependent selection and heterozygote advantage.'