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

One of the Mendel's pure strains of pea plants had green peas. How many different types of eggs could such a plant produce with regard to pea color?

1. 1

2. 2

3. 4

4. 8

A woman receives her X chromosomes from:

1. Her mother only

2. Her father only

3. Both her mother and father 

4. Mitochondria of mother only

The insertion or deletion of a base pair into the genetic code will cause a frame shift mutation unless the number of base pairs inserted or deleted is:

(1) One

(2) Two

(3) three

(4) Ten

A gene showing codominance has

(1) one allele dominant on the other

(2) alleles tightly linked on the same chromosome

(3) alleles that are recessive to each other

(4) both alleles independently expressed in the heterozygote

In his classic experiments on pea plants, Mendel did not use

(1) seed colour

(2) pod length

(3) seed shape

(4) flower position