Sickle cell anaemia is:

1.	an autosomal linked dominant trait
2.	caused by substitution of valine by glutamic acid in the globin chain of haemoglobin
3.	caused by a change in base pair of DNA
4.	characterized by elongated sickle like RBCs with a nucleus

In hexaploid wheat, the haploid (n) ar basic (x) numbers of chromosomes are:

1. n=7 and x=21

2. n=21 and x=21

3. n=21 and x=14

4. n=21 and x=7

Inheritance of skin colour in humans is an example of:

1. chromosomal aberration

2. point mutation

3. polygenic inheritance

4. codominance

Two genes R and Y are located very close on the chromosomal linkage map of the maize plant. When RRYY and rryy genotypes are hybridized, then F₂ segregation will show:

1. higher number of the recombinant types

2. segregation in the expected 9:3:3:1 ratio

3. segregation in a 3:1 ratio

4. higher number of the parental types

In pea plants, yellow seeds are dominant to green. If a heterozygous yellow-seeded plant is crossed with a green-seeded plant, what ratio of yellow and green-seeded plants would you expect in F1generation?

1. 50:50

2. 9:1

3. 1:3

4. 3:1

Which one of the following is the most suitable, medium for culture of Drosophila melanogaster?

1. Moist bread

2. Agar agar

3. Ripe banana

4. Cow dung

In which mode of inheritance do you expect more maternal influence among the offspring?

1. Autosomal

2. Cytoplasmic

3. Y-linked 

4. X-linked

In Mendel's experiments with garden peas, round seed shape (RR) was dominant over wrinkled seeds (rr), and yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F₂ generation of the cross RRYY x rryy?

If a colourblind woman marries a normal-visioned man, their sons will be:

1. all normal visioned

2. one-half colourblind and one-half normal

3. three-fourths colourblind and one-fourth normal

4. all colourblind

Cri-du-chat syndrome in humans is caused by the: