Heredity And Variations - Biology Jamb Past Questions and Answers

Question 6 :

• JAMB 1980

If a baby is a female, her mother's ovum must have been fertilized by a sperm carry the chromosome

A. X
B. XY
C. XX
D. YY
E. Y

Question 7 :

• JAMB 1981

What is the genetic ratio of a cross between homozygous tall plant and a homozygous dwarf plant?

A. 0 tall : 4 short
B. 3 tall : 1 short
C. 2 short : 2 tall
D. 1 tall : 1 short
E. 4 tall : o short

Question 8 :

• JAMB 1982

If a tall man (TT) maries a dwarf woman (gg) and they have four male children, the offspring will be

A. All short
B. Three short and one tall
C. Two short and two tall
D. One short and three tall
E. All tall

Question 9 :

• JAMB 1982

A married couple has 10 children and they are all girls. Which of the following is the CORRECT explanation?

A. The woman is incapable of producing male children
B. The man’s sperms are very weak
C. The man is not athletic enough
D. The Y component of the men’s sex chromosomes was always involved
E. The X component of the man’s sex chromosomes was always involved

Question 10 :

• JAMB 1982

If a 26 year old blind man married a young one-eyed woman and they had four children, how many of them would be blind like there father?

A. All
B. 3
C. 2
D. 1
E. None