Recessive lethal

Definition

A recessive lethal allele is a type of genetic mutation that results in the death of an organism when present in a homozygous recessive state. Heterozygous individuals carrying one copy of the lethal allele typically survive and can pass the allele to their offspring.

5 Must Know Facts For Your Next Test

1. Recessive lethal alleles often result in embryonic or early postnatal death.
2. These alleles usually remain hidden in heterozygous carriers.
3. Gregor Mendel's experiments laid foundational work, but he did not specifically identify lethal alleles.
4. Recessive lethal alleles can be identified through breeding experiments and pedigree analysis.
5. In some populations, these alleles can persist due to the survival advantage conferred by the heterozygous state.

Review Questions

• What is the outcome for an organism that is homozygous for a recessive lethal allele?
• How can recessive lethal alleles be maintained in a population?
• Why might heterozygous individuals with a recessive lethal allele survive?

Related terms

Homozygous: An individual having two identical alleles of a particular gene.

Heterozygous: An individual having two different alleles of a particular gene.

Pedigree Analysis: A diagrammatic method to study inheritance patterns over several generations within families.