The Stomach Is Bounded on Both Ends by a Sphincter

question 20

True/False

The stomach is bounded on both ends by a sphincter.

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Definitions:

Balanced Polymorphisms

A genetic equilibrium where two or more alleles persist in a population because they each confer some selective advantage that promotes survival.

Frequency-Dependent Selection

Natural selection in which a trait’s adaptive value depends on its frequency among members of a population.

Recessive Allele

An allele that produces its characteristic phenotype only when its paired allele is identical, often masked by a dominant allele in a heterozygote.

Dominant Allele

An allele that expresses its phenotype even in the presence of a recessive allele within a diploid organism.