Badin Bio Genetics Review #2

Allele

The different forms of a gene

Dominant Allele

An allele whose trait always shows up in the organism when the allele is present

Recessive Allele

An allele that is masked when a dominant allele is present

Homozygous

Having two identical alleles for a trait

Heterozygous

Having two different alleles for a trait

Genotype

An organisms genetic makeup, or allele combinations

Phenotype

The physical traits that appear in an individual as a result of its genotype

Incomplete dominance

A blended phenotype. One allele is not completely dominant over the other

Codominance

both alleles of a gene are present in the phenotype

Sex linked

when traits are determined by alleles on the sex chromosomes

Genotypic ratio

The ratio of genotypes that could appear in offspring

Phenotypic ratio

the ratio of phenotypes that could appear in offspring

Gregor Mendel

The father of genetics - Experimented with pea plants

Law of segregation

Pairs of alleles for a trait separate when gametes are formed

Monohybrid cross

a genetic cross that involves one pair of contrasting alleles for a trait

Dihybrid cross

a genetic cross in which two characteristics are tracked

Pedigree

A chart recording a line of ancestors