Mendel and the Gene Idea

Flashcards covering key vocabulary and concepts related to Mendelian genetics.

Gregor Mendel

A scientist known for his work on the laws of inheritance through experiments with garden peas.

Law of Segregation

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

Law of Independent Assortment

Mendel's law stating that genes for different traits can segregate independently during the formation of gametes.

True-breeding

Plants that produce offspring of the same variety when they self-pollinate.

Homozygous

An organism having two identical alleles for a character.

Heterozygous

An organism having two different alleles for a character.

Phenotype

The physical appearance or visible traits of an organism.

Genotype

The genetic makeup or composition of an organism.

Allele

Different forms of a gene that can exist at a specific locus.

Hybridization

The process of mating two contrasting, true-breeding varieties.

Monohybrid cross

A cross between individuals concentrating on only one trait.

Dihybrid cross

A cross between individuals examining two traits.

Codominance

A genetic scenario in which both alleles contribute to the phenotype.

Incomplete dominance

A genetic scenario where the phenotype of a heterozygote is intermediate between that of the two homozygotes.

Pleiotropy

The ability of a single gene to affect multiple traits.

Epistasis

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

Polygenic inheritance

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

Pedigree analysis

A family tree diagram that traces the inheritance patterns of specific traits.

Probability laws

Statistical rules that predict the likelihood of genetic traits being passed on to offspring.

Test cross

Breeding an organism of unknown genotype with a homozygous recessive organism to determine the unknown genotype.

Cystic fibrosis

A genetic disorder caused by a recessive allele leading to severe respiratory and digestive problems.

Sickle-cell disease

A genetic disorder caused by a specific mutation in the hemoglobin gene, leading to sickle-shaped red blood cells.