genotype	alleles contained in an organis's cells
phenotype	visual characteristics of organism determined by genotype and environment
dominant allele	allele affecting the phenotype of heterozygous as much as for homozygous
recessive allele	allele which only affect the phenotype when dominant allele is not present
codominant alleles	both alleles affect phenotype of heterozygous organism
locus	position of a gene on the chromosome
carrier	healthy individual carrying copy of a recessive gene causing genetic disease for homozygotes
test cross	testing a suspected heterozygote by crossing it with a known recessive homozygote
genome	all of genetic information of organism
allele	variety of a gene having the same locus
homologous chromosomes	chromosomes of the same pair, the sames genes in the same sequence, not the same alleles