An abnormal human baby with 'XXX' sex chromosomes was born due to

1. formation of abnormal sperms in the father

2. formation of abnormal ova in the mother

3. fusion of two ova and one sperm

4. fusion of two ova and two sperm

Alleles are

1. different phenotype

2. true breeding homozygotes

3. different molecular forms of a gene

4. heterozygotes

Fruit color in squash is an example of 

(1) recessive epistatis

(2) dominant epistatis

(3) complementary genes

(4) inhibitory genes

A human female with turner's syndrome

(1) has 45 chromosomes with XO

(2) has one additional X-chromosome

(3) exhibits male characters

(4) is able to produce children with normal husband

Which of the following statements is not true of two genes that show 50% recombination frequency?

(1) the genes may be on different chromosomes 

(2) the genes are tightly linked

(3) the genes show independent assortment

(4) If the genes are present on the same chromosome, they undergo more than one crossovers in every meiosis

If two persons 'AB' blood group marry and have sufficiently large number of children, these children could be classified as 'A' blood group : 'AB' blood group : 'B' blood group in 1 : 2 : 1 ratio. Modern technique of protein electrophoresis reveals presence of both 'A' and 'B' type proteins in 'AB' blood group individuals. This is an example of

(1) codominance

(2) incomplete dominance

(3) partial dominance

(4) complete dominance 

Which Mendelian idea is depicted by a cross in which the F₁ generation resembles both the parents?

(1) Incomplete dominance

(2) Law of dominance

(3) Inheritance of one gene

(4) Codominance

The incorrect statement with regard to haemophilia is

(1) it is a sex-linked disease

(2) it is a recessive disease

(3) it is a dominant disease

(4) a single protein involved in the clotting of blood effected

A normal-visioned man whose father was colourblind, marries a woman whose father was also a colourblind. They have their first child as a daughter. What are the chances that this child would be colourblind?

(1) 100%

(2) 0%

(3) 25%

(4) 50%

F₂ generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1:2:1. It represents a case of 

(1) codominance

(2) dihybrid cross

(3) monohybrid cross with complete dominance

(4) monohybird cross the incomplete dominance