chapter 18 Flashcards
single-gene traits
each one is determined by variation at a single gene and the traits for the most part are not influenced by the environment
complex traits
influenced by multiple genes as well as by the environment
quantitative traits
measured along a continuum with only small intervals between similar individuals
environmental risk factor
characteristic in a person’s surroundings that increases the likelihood of developing a particular disease
inbred lines
a true breeding, homozygous strain
normal distribution
bell-shaped curve
norm of reaction
a graphical depiction of the change in the phenotype across a range of environments
genotype-by-environment interaction
variation in the effects of the environment on different genotypes
heritability
in a population, the proportion of the total variation in a trait that is due to genetic differences among individuals
Monozygotic twins
identical twins that arise from a single fertilized egg
concordance
the percentage of cases in which both members of a pair of twins show the traits when it is known that at least one member shows it
pleiotrophy
a single gene that has multiple effects
