Mendel and the Gene

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

Phenotype

The physical appearance or observed behavior of an organism.

Genotype

The genetic makeup of an organism.

Dominant

The allele that determines the organism's appearance when present.

Recessive

The allele that has no noticeable effect on appearance when a dominant allele is present.

Homozygous

An organism with two identical alleles for a character.

Heterozygous

An organism that has two different alleles for a gene.

Law of Segregation

The law stating that the two alleles for a heritable character separate during gamete formation.

Punnett Square

A diagram used to predict the results of a genetic cross.

Monohybrid Cross

A cross between individuals that are heterozygous for one character.

Dihybrid Cross

A cross between individuals differing in two characters.

Polygenic Inheritance

Inheritance of a trait that is controlled by multiple genes.

Pleiotropy

The ability of a single gene to affect multiple phenotypic traits.

Epistasis

A phenomenon where one gene affects the expression of another gene.

Complete Dominance

A form of dominance where the phenotype of the heterozygote is the same as that of the homozygous dominant.

Incomplete Dominance

A type of inheritance in which the phenotype of heterozygotes is intermediate between the two homozygotes.

Codominance

A condition in which both alleles at a gene locus are expressed in the phenotype.

Testcross

Breeding a mystery individual with a homozygous recessive individual to determine the genotype of the mystery individual.

Carriers

Heterozygous individuals who carry a recessive allele but are phenotypically normal.

Phenotypic Ratio

The ratio of different phenotypes in the offspring of a genetic cross.

Genetic Linkage

When genes are located close to each other on the same chromosome and tend to be inherited together.