The two alleles of a gene pair are located on:

1. Homologous sites on homologous chromosomes

2. Heterologous sites on homologous chromosomes

3. Homologous sites on heterologous chromosomes

4. Heterologous sites on heretologous chromosomes

Male heterogamety is not seen in:

1. Humans

2. Melandrium album

3. Birds

4. Fruit fly

The trait shown in the given pedigree chart is most likely a/an:

1. Autosomal recessive trait

2. Autosomal dominant trait

3. Sex linked recessive trait

4. Sex linked dominant trait

Aneuploidy results from :

1. Point mutations

2. Gross structural changes in chromosomes

3. Failure of cytokinesis after telophase stage of cell division

4. Failure of segregation of chromatids during cell division 

Which of the following are correct regarding linked genes?

I. are located near each other on the same chromosome.

II. violate the law of independent assortment

III. segregate together during meiosis

(1) Only I and II

(2) Only I and III

(3) Only II and III

(4) I, II, III

Consider the cross AaBb x AaBb. If the alleles for both genes exhibit complete dominance, what genotypic ratio is expected in the resulting offspring?

1. 1:1:1:1

2. 9:3:3:1

3. 3:6:3:1:2:1

4. 1:2:1:2:4:2:1:2:1

Two phenotypically normal individuals have an affected child. What can we conclude about the parents?

1. they both carried the diesease allele

2. they are not the parents of the child

3. they are affected

4. no conclusions can be drawn

What is the basis of pleiotropy?

1. A spontaneous mutation during the replication of DNA.

2. Interrelationship between various metabolic pathways in the body.

3. Chromosomal aberration as chromosomes are the vehicles of genes.

4. the behaviour of chromosomes during meiosis or gamete formation.

A female whose father was colorblind marries and normal male whose father was also colorblind. What is the probablility that their daughter will be colorblind?

1. 0 %

2. 25 %

3. 50 %

4. 75 %

In humans, the dominance relationship between the A and B alleles of ABO blood group gene is an example of

(1) complete dominance.

(2) incomplete dominance.

(3) codominance.

(3) epistasis