Genes and Selective Breeding – Vocabulary Review

Vocabulary flashcards summarizing key genetic inheritance terms and the concept of selective breeding from the lecture notes.

Gene

A region of DNA that codes for a protein.

Allele

An alternative version of the same gene.

Dominant allele

An allele that is expressed in the phenotype whenever it is present.

Recessive allele

An allele expressed only when two copies are present (no dominant allele is present).

Multiple alleles

A situation where more than two allele forms exist for a single gene within a population.

Incomplete dominance

An inheritance pattern in which the heterozygote shows an intermediate phenotype because neither allele is fully dominant.

Co-dominance

An inheritance pattern in which both alleles in a heterozygote are fully expressed, producing a combined phenotype.

Heterozygous

Having two different alleles for a particular gene.

Homozygous

Having two identical alleles for a particular gene.

Sex chromosomes

The pair of chromosomes (X and Y in humans) that determine biological sex.

X chromosome

The larger sex chromosome; females have two (XX), and it carries many genes.

Y chromosome

The smaller sex chromosome; found only in males (XY) and contains fewer genes.

Selective breeding

The process of choosing parents with desired traits and breeding them over several generations to enhance those traits.