Transcript Genetics

GENERAL GENETICS
(PRACTICAL SESSION)
BIO221
LECTURER
ALSHEHRI, DOKHNAH SAEED
[email protected]
QUESTION 1:
• How can the child of two brown-eyed
parents have blue eyes? ( in such case
which kind of dominance presents
here?.)
QUESTION 2:
• If two pea plants hybrid for red color
are crossed. What is the expected ratio
of flower color among the offspring?
QUESTION 3:
• A lethal gene B is found on one of the X
chromosomes of an infected female. If
she marries a normal male, what is the
possibility that their male child will be
affected with this gene?
QUESTION 4:
• A mother with blood type A and a
father with type B blood wish to find out
if it is possible for their children to have
blood type O. Please explain.
QUESTION 5:
• In cattle, black is dominant over red. A farmer
wants to know if his black bull is a pure strain.
When the black bull was mated with a red cow,
over a period of years, several calves were born.
Of these calves, approximately 50 were black and
50 were red. What is the genotype of the bull?
What is the genotype of the black calves? The red
calves? What we called this kind of testing?
QUESTION 6:
• 2. A woman with brown eyes and dark hair married to a man with
blue eyes and blonde hair. All the children have dark hair, but half
have blue eyes and the other half have brown eyes.
* Provide the genotypes of the parents and the children. Let (E) represent
dominant brown eye colour and (e) recessive blue eye colour. Let (B)
represent dominant brown hair colour and (b) recessive blonde hair
colour. (Show all your workings in punnet squares).
QUESTION 7:
• In a case of disputed parentage , the mother
of an illegal child is blood type N, the child
MN, and one suspected father is N and the
other MN.
• How would you work out the case?