Question

some traits have multiple alleles in a population. For example, ABO blood type has three Alleles: ________, _________, and ________, __________ and ___________ are codominant. If both parents are AB tye, what are the possible genotype of their children? ____________________________________________?

A cross between a parent with dominant phenotype (A) and a parent with recessive phenotype (a) is called a ______________ cross. It is used to find out the genotype of the dominant parnet. If all offspring have dominant phenotype, this parent's genotype should be _____________; if dominant to recessive is 1:1, this parent's femotype should be ___________?

Hemophilia is a __________________ disorder. Both parents are normal, their son has hemophilia. What is the mother's genotype? _______________. What is the father's genotype _________________? What is the son's genotype ________________? Her possible genotype should be __________ or ________?

Answer 1

Three alleles - A,B and O allele.

A and B are codominant.

Possible blood group of children - A, B and AB.

Cross with dominant parent with recessive parent is called test cross.

If all are dominant then genotype of parent is AA.

If ratio of dominant to recesive is 1:1 then genotype is Aa.

Hemophilia is X linked recessive disorder.

If son has hemophilia then genotype of mother is X^cX.

Father's genotype is XY.

Son's genotype is X^cY.

Daughter's genotype should be X^cX or XX.