DNA, Genese & Chromosomes terms

Vocabulary flashcards based on lecture notes about genetics, covering terms like gametes, DNA, chromosomes, genes, alleles, genotype, phenotype, and dominant/recessive traits.

Gamete

A sex cell; in humans, sperm and eggs.

DNA

A large and complex polymer made up of two strands forming a double helix that determines the characteristics of a living organism. Each person's DNA is unique (except for identical twins).

Chromosome

Found in pairs inside the cell's nucleus, these are long threads of DNA made up of many genes, with one chromosome inherited from each parent. They occur in pairs.

Gene

A small section of DNA on a chromosome that codes for a particular sequence of amino acids to make a specific protein; the unit of heredity.

Allele

Different versions of the same gene (e.g., blue eye color allele and brown eye color allele).

Homozygous

Having two identical alleles for a particular gene.

Heterozygous

Having two different alleles for a particular gene.

Genotype

The collection of alleles that determine characteristics.

Phenotype

The visible characteristics of an organism which occur as a result of its genes (e.g., blue eyes or brown hair).

Dominant Allele

An allele that is expressed in the heterozygote and is represented by a capital letter (e.g., A). Only one copy of this allele is needed for the trait to be expressed.

Recessive Allele

An allele that is only expressed if the individual has two copies and does not have the dominant allele of that gene. Represented by a lower-case letter (e.g., a).