genotype to phenotype

gene

unit of heredity; sequence of DNA that codes for a functional product

allele

specific version of a gene

genotype

genetic makeup of an organism

phenotype

observable physical & physiological traits of an organism

homozygous

having 2 identical alleles for a given gene

heterozygous

having 2 different alleles for a given gene

dominant allele

allele that is fully expressed in the phenotype of a heterozygote

recessive allele

allele whose phenotype effect is not observed in a heterozygote

law of segregation

2 alleles for a heritable character separate during gamete formation & end up in different gametes

law of independent assortment

genes for different traits assort independently of one another during gamete formation

test cross

crossing an individual of unknown genotype (but dominant phenotype) with a homozygous recessive individual to determine the unknown genotype