2002 - JAMB Biology Past Questions and Answers - page 5
41
If XN is the dominant allele for normal vision and Xn the recessive allele for colour blindness, a boy with the genotype YXn will be
A
have normal vision
B
be colour-blind
C
be totally blind
D
be a carrier of colour blindness
correct option: b
Users' Answers & Comments42
The first four children of a couple were all girls. The probability that the fifth will also be a girl is
A
1/5
B
1/4
C
1/3
D
1/2
correct option: d
Users' Answers & Comments43
Genetic counselling is important when a marriage is planned between a
A
Rh- woman and Rh man+
B
Rh- woman and Rh- man
C
Rh+ woman and Rh+ man
D
Rh+ woman and Rh- man
correct option: a
Most people — about 85% — are Rh positive. But if a woman who is Rh negative and a man who is Rh positive conceive a baby, there is the potential for a baby to have a health problem. The baby growing inside the Rh-negative mother may have Rh-positive blood, inherited from the father. Approximately half of the children born to an Rh-negative mother and Rh-positive father will be Rh positive
Users' Answers & Comments44
What proportion of the offspring of a cross between two heterozygous parents will exhibit the recessive condition phenotypically
A
1/4
B
1/2
C
3/4
D
4/4
correct option: a
Users' Answers & Comments45
A
make the body react to emergencies
B
lower blood glucose level
C
raise the level of calcium ions in the blood
D
facilitate the development of facial hairs
correct option: d
Users' Answers & Comments46
A
IV
B
III
C
II
D
I
correct option: c
Users' Answers & Comments47
A
IV->II->III->I
B
III->II->I->IV
C
II->III->IV->I
D
I->III=>II->IV
correct option: a
Users' Answers & Comments48
An amoeba and an unlaid chicken egg are
A
anial tissue
B
organelles
C
single cell
D
organisms
correct option: c
Users' Answers & Comments49
In corns, food is usually stored in the
A
leaves
B
stems
C
roots
D
buds
correct option: b
Users' Answers & Comments50
The animals that move by means of flagella include
A
Chlamydomonas and Euglena
B
Planeria and Amoeba
C
Amoeba and Hydra
D
Paramecium and Planeria
correct option: a
Users' Answers & Comments