Genetics

Test cross Individual of unknown genotype is crossed with a homozygous recessive individual Determine the genotype of an individual whose phenotype is dominant

Complete Dominance Complete Dominance – one allele completely dominant over the other

Incomplete Dominance Incomplete dominance – two or more alleles influence the phenotype resulting in a phenotype intermediate between the dominant and recessive traits R=red r=whiteRr  pink

Codominance Codominance – both alleles for a gene are expressed in a heterozygous offspring – neither is dominant or recessive Rr  red & white polka dots

Multiple alleles- 3 or more alleles of the same gene Blood Types I A I B i I A I Aor I A i=Blood type A I B I Bor I B i=Blood type B I A I B =Blood type AB ii=Blood type O

Sex- linked inheritance Traits controlled by genes located on the sex chromosomes X-linked gene Y-linked gene X-linked traits more common in males Sex-Influenced Inheritance – traits affected by how much sex hormones are present