Point mutation is induced by:
1. Adenine
2.  Guanine
3.  3-cytosine
4.  5-bromouracil

Reason for trisomy in Down's syndrome is:
1.  Non-disjunction during sperm formation
2.  Non-disjunction during egg formation
3.  Non-disjunction at the time of egg or sperm formation
4.  Addition of one extra chromosome during mitosis

Multivalent chromosome is formed by:
1.  Inversion
2.  Deletion
3.  Reciprocal translocation
4.  Point mutation

A normal leaf cell has how many genomes?
1.   1
2.   2
3.   3
4.   4

Mental retardation in man occurs due to:
1. Loss of one X chromosome
2. Addition of one X chromosome
3. Slight growth in Y
4. Overgrowth in Y

ABO blood group has:
1.  Two codominant and one recessive allele
2.  Two codominant and two recessive allele
3.  Two incompletely dominant genes
4.  Two pseudo alleles

A normal woman, whose father was colour-blind is married to a normal man. The sons would be:
1. 50% colour-blind
2. All normal
3. All colour-blind
4. 75 % colour-blind 

The recessive genes located on X-chromosomes in humans are always:

1. Sub-lethal

2. Expressed in males

3. Expressed in females

4. Lethal

A male human is heterozygous for autosomal genes A and B and is also hemizygous for hemophilic gene h. What proportion of his sperm will be ABH?

A self-fertilizing trihybrid plant forms: