ANTHROP 2E03 Lecture Notes - Lecture 5: Abo Blood Group System, Y Chromosome, Antigen

• School: McMaster University
• Department: Anthropology
• Course: ANTHROP 2E03
• Professor: Andrew Wade

Document Summary

Mm homozygotes only express the m antigen. Nn homozygotes only express the n antigen. Mn heterozygotes express both the m and n antigens. With codominance you will get a different picture; 3 different types of phenotype. It is slightly incorrect to be writing big y and little y. 3 different alleles here from the same gene. A and b are codominant and o is recessive to a and to b. In humans and other organisms there are also a pair of sex chromosomes. Females will be xx and males will be xy. The y chromosome is much smaller than the x and carries just a few genes, and makes the inheritance of sex linked traits a bit more complicated. Because males are short on genetic material, we got only one copy of x; it"s a condition called hemizygote. If they got recessive allele, then they got the trait. If they don"t have the disease allele, then it"s not expressive.