Genetics: Exceptions 2026

Genetics vocab

incomplete dominance

when one allele doesn’t completely mask another resulting in a blending of both.

codominance

when one allele doesn’t mask another resulting in an individual that will show both alleles at the same time

sex-linked traits

trait that is controlled by a gene found on a sex chromosome

pedigree

a diagram that shows the occurrence of a genetic trait in several generations of a family

carrier

individual who has one copy of the allele for a recessive disorder and does not exhibit symptoms

dihybrid (two trait) cross

cross that shows how two different traits are passed on from parents to offspring

polygenic inheritance

when a trait is influenced by two or more genes

multiple alleles

having three or more alleles for a given gene

autosomal chromosome

one of the numbered chromosomes (1-22)

sex chromosome

chromosome involved in sex determination (X or Y)