Genetics

Recessive

열성

Definition

A trait or allele that is expressed in the phenotype only when two copies are present in a homozygous individual.

Detailed Explanation

Recessive alleles can persist in populations at high frequency because natural selection cannot act on them when masked by a dominant allele in heterozygotes. Inbreeding increases the probability of individuals becoming homozygous for harmful recessive alleles — a major problem in small, isolated populations. Many hereditary diseases (cystic fibrosis, sickle cell in certain contexts) involve recessive alleles.

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