Mendel and the Gene Idea

These flashcards cover key vocabulary and concepts related to Mendelian genetics as discussed in the lecture notes.

P Generation

The parental generation that consists of true-breeding parents.

F1 Generation

The first filial generation, which consists of the hybrid offspring of the P generation.

Dominant Trait

A trait that appears in the F1 generation, masking the effect of the recessive trait.

Recessive Trait

A trait that is masked by the dominant trait and does not appear in the F1 generation.

Alleles

Alternative versions of a gene that account for variations in inherited characters.

Homozygous

An organism with two identical alleles for a character.

Heterozygous

An organism that has two different alleles for a gene.

Phenotype

The physical appearance or observable traits of an organism.

Genotype

The genetic makeup or allele combinations of an organism.

Law of Segregation

Mendel's law stating that the two alleles for a heritable character separate during gamete formation.

Testcross

A breeding experiment used to determine an individual's genotype by crossing it with a homozygous recessive individual.

Dihybrid Cross

A cross between two organisms that differ in two characters.

Incomplete Dominance

A type of inheritance where the phenotype of heterozygotes is intermediate between the phenotypes of the two homozygotes.

Codominance

A type of inheritance where both alleles are expressed in the phenotype of the heterozygote.

Pleiotropy

The ability of a single gene to have multiple effects on an individual's phenotype.

Polygenic Inheritance

A type of inheritance in which multiple genes influence a single trait.

Epistasis

A genetic interaction where one gene affects the expression of another gene.

Environmental Impact on Phenotype

The influence of environmental factors on the expression of genes in determining phenotype.

Recessively Inherited Disorder

A genetic disorder that occurs only in individuals who are homozygous for the recessive allele.

Dominantly Inherited Disorder

A genetic disorder caused by a dominant allele, often rare.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Aneuploidy

A condition in which an individual has an abnormal number of chromosomes.