key terms Flashcards
define chromosome
a long section of DNA coiled around histones that is made up of many genes
define heterozygous
a pair of homologous chromosomes carrying two different alleles for a single gene
define gene
a section of DNA which codes for a particular protein
define locus
the position of a gene on a chromosome
define allele
an alternative version of a gene
define genotype
the combination of alleles that an organism has for a gene
define phenotype
expression of genes and its interaction with the environment
define dominant
allele that is always expressed if present
define recessive
allele that is only expressed if there is no dominant allele present
what is monogenic inheritance
inheritance of a characteristic that is controlled by only 1 gene
- eg. inheritance of cystic fibrosis
define homozygous
a pair of homologous chromosomes that carry the same alleles for a gene
define codominant
both alleles are equally dominant and both are expressed in phenotype
define multiple alleles
more than 2 alleles for a single gene
define sex linkage
gene whose locus is on X chromosome
define autosomal linkage
genes located on same chromosome (not sex chromosomes)
