Post-Mendelian Genetics Flashcards

Flashcards covering key vocabulary and concepts from a lecture on Post-Mendelian Genetics.

Linked Genes

Genes located on the same chromosome that tend to be inherited together.

Gene Recombination

The process by which alleles of linked genes can be separated, leading to new combinations of alleles.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Recombinants

Offspring with new combinations of traits not seen in the parental types, resulting from crossing over or independent assortment.

Lethal Genes

Genes that are essential for survival, but have alleles that can cause death when present in certain combinations.

Recessive Lethal Allele

An allele that causes death of the organism when present in a homozygous condition.

Dominant Lethal Allele

An allele that causes death of the organism in both homozygous and heterozygous conditions.

Multiple Alleles

Genes that have more than two allelic forms within a population.

ABO Blood Group System

A blood group system in humans controlled by a single gene with three alleles (IA, IB, IO).

Discontinuous Variation

Individuals show clear-cut differences with no intermediates between them; characteristics controlled by one or two major genes.

Continuous Variation/Polygenic Inheritance

One character is controlled by many genes (polygenes) working together to bring about the phenotype.

Epistasis

Interaction between two different genes where one gene hides the expression of another gene.

Hypostatic Gene

The gene whose expression is masked or hidden by another gene.

Epistatic Gene

A gene that masks or hides the expression of another gene.

Hypostasis

A situation in which a (hypostatic) gene is hidden by another (epistatic) gene.

Pleiotropy

The multiple phenotypic effects of a single gene.

Complementary Genes

Genes interact together to produce an effect which is different from that given by either of them separately.