Inheritance key terms Flashcards
What is diploid?
an organism with a pair of homologous chromosomes - it has 2 alleles of each gene
What is a gene?
a sequence of DNA that codes for a protein
What is an allele?
a version of a gene e.g. A or B or O
What is a genotype?
the combination of alleles that an organism has e.g. AA, BB, AB, Ao, Bo
What is a phenotype?
the physical expression of the genotype and its interaction with the enviroment e.g. skin colour
What is a dominant allele?
an allele that is always expressed in the phenotype Ao Bo
What is a recessive allele?
alleles that are only expressed when homozygous e.g. oo
What are codominant alleles?
both alleles are expressed in phenotype - phentotype is intermediate e.g. AB
What is homozygous?
when both alleles are the same e.g. AA, BB
What is heterozygous?
when alleles are not the same e.g. AB, Ao, Bo
What is the locus?
the location of a gene on a chromosome - alleles of a gene always have the same locus
