Monohybrid Inheritance and Mendelian Genetics Vocabulary

Vocabulary flashcards covering fundamental genetic terms, Mendel's first and second laws, codominance, multiple alleles, expressivity, and the Rh factor condition based on the lecture notes.

Gene

The basic unit of inheritance.

Character

A term used as a synonym for a hereditary property.

Allele

A form of expression of a gene.

Phenotype

The set of visible, measurable, or quantifiable characters of an organism.

Genotype

The composition of maternal and paternal alleles in an individual.

Homozygous Genotype

A pure breed genotype consisting of a pair of alleles of equal intensity (e.g., $AA$, $aa$, $RR$).

Heterozygous Genotype

A hybrid or carrier genotype consisting of a pair of alleles for the same character that have different intensities (e.g., $Aa$, $Bb$, $Rr$).

Dominant Allele

An allele (represented by a capital letter) that is always expressed whenever present, masking another allele of lower intensity.

Recessive Allele

A weak allele (represented by a lowercase letter) that is expressed only when paired with another allele of equal intensity in a homozygous state.

Lethal Allele

An allele that can cause death or diminish vital capacities, which can be dominant, recessive, complete, or incomplete.

Test Cross

A genetic cross between an individual with a dominant phenotype ($A\_$) and a homozygous recessive individual ($aa$) to determine the exact genotype of the dominant individual.

Backcross

A cross between a parental individual and a member of its offspring generation.

Filial Generation

The generation of offspring resulting from a cross, designated by the letter $F$.

First Law of Mendel (Law of Uniformity)

The principle stating that when crossing two pure breeds, all individuals in the first generation ($F_1$) have the same genotype and express the same phenotype.

Second Law of Mendel (Law of Independent Segregation)

The principle stating that alleles determining a character separate independently during meiosis.

Codominant Alleles

Alleles with equal intensity where neither is dominant nor recessive, resulting in a heterozygous genotype that is phenotypically distinct from the homozygous states.

Multiple Alleles

A condition where a gene has multiple potential alleles, allowing one phenotype to correspond to two or more genotypes, as seen in human ABO blood groups.

Expressivity

The variable degree or intensity with which a penetrant genotype is expressed in the phenotype.

Erythroblastosis Fetalis

A condition caused by anti-Rh antibodies crossing the placenta from maternal circulation, leading to the agglutination of fetal Rh-positive red blood cells.