Codominance

Question 1

what is co-dominance?

Answer 1

In some instances, the heterozygote has a phenotype that is different to either of the homozygotes.

If the heterozygotes phenotype shows both of the other phenotypes, it is called co-dominance.

Question 2

co dominance symbols using cow

Answer 2

red cow
homozygous CRCR - (R is subscript)

roan cow
heterozygous roan CRCW (red AND white) (R and W in subscript)

white bull
homozygous white CWCW
(W in subscript)

Question 3

how are human blood types inherited

Answer 3

codominance + dominant/recessive

Question 4

writing used for blood types

Answer 4

A type blood: IA IA or IAi

B type blood: IB IB or IBi

AB type blood: IA IB

O type blood: ii

(A’s and B’s in subscript)

Question 5

what else can blood groups be used for

Answer 5

Blood groups can also be used in paternity cases where the father of the child is in dispute.

Question 6

what can’t blood groups do

Answer 6

Blood groups can NOT prove that a man is the father but it can be used to disprove it.

Question 7

why is blood typing done first to end a dispute on who is the father

Answer 7

If a man’s blood type matches, DNA testing can then be undertaken to determine whether he is the child’s father. This is expensive and time
consuming which is why blood analysis is done first.

Question 8

see slides 43+44 for eg’s