inheritance Flashcards
genotype
The genetic makeup of an individual (the alleles they possess)
phenotype
the characteristics of an individual that result from the expression of their genes and their interaction with the environment
homozygous
having 2 identical alleles of a gene
heterozygous
having 2 different alleles for a particular gene
dominant
an allele whose effects always show in the phenotype, even in a heterozygous individual
recessive
an allele whose effects only show when there is no dominant allele present- when the individual is homozygous for the allele
codominant
alleles whose effects both show in the phenotype of a heterozygous individual
multiple alleles
a gene that has more than two allelic forms
autosome
a chromosome that is not a sex chromosome
epistasis
when the allele of one gene masks the expression of the alleles of another gene
linked genes
different genes on the same chromosome
carrier
a person carrying an allele which is not expressed in the phenotype but can be passed on to the offspring
gene
a sequence of nucleotide bases on DNA that codes for a specific polypeptide
locus
the position of a gene on a chromosome
homologous chromosomes
a pair of chromosomes with the same genes at the same loci
allele
one form of a gene
sex linked gene
a gene found on a sex chromosome, X or Y
evidence to show that condition is caused by a recessive allele
-2 parents who do not have the condition
-child who does have the condition
therefore: both parents must be carriers of recessive allele, but due to presence of dominant allele do not have the condition themselves
evidence that the condition is caused by a dominant allele
2 parents who have the condition
child who does not have the condition
both parents must be carriers of the the recessive allele but due to the presence of the dominant allele they have the condition themselves
