Blood type is controlled by 3 alleles: A, B, O. A & B are codominant, O is recessive.
1. a) What are the two genotypes
possible for a person who as A blood? ____AA, AO___
b) What genotype does a person with AB blood have? ____AB_______
c ) What genotype does a person with O blood have? ____OO______
d) What are the two genotypes possible for a person who as B blood? ______BB, BO_____
2. A man with type AB blood is married
to a woman also with type AB blood. What percentage of their children will have:
A blood? ___25%___ B blood? _25%___ O blood _0%____ AB blood _50%______
3. A man has type B blood (genotype BB) is married to a woman with type O blood. What blood type will all their children have? ____B___ What is the genotype of the children? __BO____
4. A woman with type A blood (genotype AO) is married to a type B person (genotype
BO). What proportion of their children will have:
A blood? __25%____ B blood? __25%___ O blood __25%__ AB blood __25%_____
5. A woman with type A blood is claiming that a man with type AB blood is the
father of her child who is type B.
Could this man be the father of the child? ___yes_________ Show the possible
crosses; remember that the woman can have AA or AO genotypes.
Assuming that he is the father, what must the mother's genotype be? _AO_
6. A man with type AB blood is married to a woman with type O blood. They have two natural children and one adopted child. Jane has type A blood, Bobby has type B blood, and Grace has type O blood. Which child was adopted? _____Grace_______
Teacher's note- students may have less trouble with these if you tell them to assign them letters like blood type letter, A, B, and O
7. Show Genotypes
..................SS...............................SD......................DD.................................OO.................
8. If a star-eyed smiley (homozygous) is crossed with a dot-eyed smiley (also homozygous) what will all of their offspring look like?
SS x DD , all offspring SD
9. If the pair in the cross above were both heterozygous, what percentage of
the offspring will be: SD x SD
Starry __25%__ Star-dot _50%____ Dot __25%_ Square __0%__
10. If a starry-dot eyed smiley is
crossed with a square eyed smiley what percentage of the offspring will be:
Starry _50%___ Star-dot ______ Dot __50%__ Square ____
11. If two starry-dot eyes smileys
are crossed, what percentage of the offspring will be:
Starry _25%___ Star-dot
__50%__ Dot _25%___ Square _0%__
Determine the genotypes of the following Sunnys. It is a multiple allele trait, spiked and circles are codominant and the bare trait is recessive.
12. Show genotypes: SS, SC, CC, OO
13. If a spiked sunny (heterozygous)
is crossed with a bare sunny, what percentage of the offspring will be bare?
___50%______
What percentage will be spiked? ___50%______
14. If a spike-circle sunny is crossed with a heterozygous spike sunny, how
many of the offspring will be spiked? ___50%__
How many will be circles? ___25%_______
How many will be spike-circles? _______25%______
15. A female sunny who is spiked is married to a male sunny who is circle. They
have a child who is bare. What must be the genotypes of the two parents? ___SO x CO_____________