331.
In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree.
A
$$X$$- linked recessive
B
Autosomal recessive
C
$$X$$-linked dominant
D
Autosomal dominant
Answer :
Autosomal recessive
332. In Down's syndrome of a male child, the sex complement is
A
$$XO$$
B
$$XY$$
C
$$XX$$
D
$$XXY$$
Answer :
$$XY$$
333. A bacterium modifies its DNA by adding methyl groups to the DNA, It does so to
A
Clone its DNA
B
Be able to transcribe many genes simultaneously
C
Turn its gene on
D
Protect its DNA from its own restriction enzyme
Answer :
Protect its DNA from its own restriction enzyme
334. In Melandrium what is function of IV region of Y-chromosome
A
Promote femaleness
B
Induce male reproductive
C
Pairing and regular disjunction of X and Y chromosome
D
Helps in non disjunction
Answer :
Pairing and regular disjunction of X and Y chromosome
335. A man with blood group B marries a female with blood group A and their first child is having blood group B. What is the genotype of child
A
IAIB
B
IAI°
C
IBI°
D
IBIB
Answer :
IBI°
336. Mental retardation in man associated with sex chromosomal abnormality is usually due to
A
increase in $$X$$ complement
B
moderate increase in $$Y$$ complement
C
large increase in $$Y$$ complement
D
reduction in $$X$$ complement
Answer :
increase in $$X$$ complement
337. Dihybrid test cross ratio proposed by Mendel is
A
9 : 3 : 3 : 1
B
1 : 1 : 1 : 1
C
1:2:2:4:1:2:1:2:1
D
3 : 1
Answer :
1 : 1 : 1 : 1
338. Mendel enunciated how many principles of inheritance
A
One
B
Two
C
Three
D
Four
Answer :
Four
339. Out of 8 ascospores formed in Neurospora the arrangement is $$2a : 4a : 2a$$ showing
A
No crossing over
B
Some meiosis
C
Second generation division
D
First generation division
Answer :
Second generation division
340. The most striking example of point mutation is found in a disease called
A
thalassemia
B
night blindness
C
down's syndrome
D
sickle cell anaemia
Answer :
sickle cell anaemia