Beyond Mendel

INCOMPLETE DOMINANCE Sometimes not all traits are completely ___________ or ___________, instead neither traits are dominant. When this occurs there is a ____________ of the two traits and it is called ______________________. Instead of having just ___ visible phenotypes, there are ___ The blended intermediate trait is always the ________________. Letters are always ________________ to show incomplete dominance. Ex. Red (_____) or white (_____) snapdragons are homozygous, while pink flowers are heterozygous (_____) dominant recessive “blending” incomplete dominance 23 third phenotype heterozygous RRR’R’ RR’

Perform a cross between 2 pink snapdragons and state the phenotypes and genotypes of this cross. P: F 1 : Genotype: Phenotype: RR’ x RR’ R RʹRʹ R RʹRʹ RRRR’ R’R’ RR: 2 RR’ : R’R’ 25% red, 50% pink, 25% white

CO-DOMINANCE In some cases both alleles are _____________ and both alleles are expressed in the heterozygous form. These alleles are said to be _______________. Ex.Feather colour in chickens is governed by 2 dominant alleles. Black birds are homozygous for the B allele and white birds are homozygous for the W alleles. The heterozygous is NOT grey as one would expect in incomplete dominance but instead a checkered pattern of both black and white feathers are seen. dominant co-dominant

Perform a cross between 2 checkered chickens. Give the phenotypes and genotypes of this cross. P: F 1 : Genotype: Phenotype: BW x BW BW B W BBBW WW BB : 2 BW: WW 25% black, 50% checkered, 25% white

MULTIPLE ALLELES When genes have more than ___ alleles they are said to have _________________ and are a result of multiple gene inheritance. Human blood types is an example where 3 alleles are involved: ______________. Each person has ___ of the 3 possible alleles, and each determines if the red blood cell possesses a certain glycoprotein. Type A has ___ glycoproteins, type B has ___ glycoproteins, type AB has ___________ glycoproteins and type O have ____ glycoproteins. The 3 alleles for human blood types are ___________. __________ are dominant over ____ __________ are co-dominant and expressed equally. 2 multiple alleles A, B, and O 2 AB A and B O I A, I B, i I A and I B i

PhenotypeGenotype A I A I A or I A i BI B I B or I B i ABI A I B Oi Can receive blood from: Can donate blood to: A and O B and O A, B, AB, and O O A and AB B and AB AB A, B, AB, and O

Another factor with blood typing is another glycoprotein called ____________. We know it as either ______ or ______ blood. If a person is ____ for antigen D, then their blood can recognize this and will accept blood from this donor. If a person is ____, then they cannot recognize this antigen, and if received their blood with coagulate and die  Type ____ is known as the _________________ because it can be received by any blood type. Type _____ is the ____________________ because it can receive any blood type. If a person received the wrong blood type, their red blood cells cannot recognize the foreign glycoproteins and the body attacks the new blood causing coagulation and death. Rhesus Rh+Rh- + - Ouniversal donor ABuniversal recipient

Ex.If a father with blood type B and a mother with blood type A have a child with blood type O, is this possible? Explain using Punnett squares. I B I B x I A I A I B i x I A I A I B I B x I A iI B i x I A i IAIA IAIA IBIB IBIB IAIA IAIA IBIB i IAIA i IBIB IBIB IAIA i IBIB i IAIBIAIB IAIBIAIB IAIBIAIB IAIBIAIB IAIBIAIB IAIBIAIB IA iIA iIA iIA i IAIBIAIB IB iIB i IAIBIAIB IB iIB i IAIBIAIB IB iIB i IA iIA ii ii i Yeah Baby!

Seatwork/Homework Read Section 4.4 (p. 142 – 145) Answer # 5 – 7, 9 – 12 (p. 146)