The point mutation leading to sickle cell anaemia occurs:

1. at sixth position in the beta chain of haemoglobin
2. at sixth position in the alpha chain of haemoglobin
3. at sixth position in the beta chain of myoglobin
4. at sixth position in the alpha chain of myoglobin

In cases of Phenylketonuria:

1. The affected individual lacks an enzyme that converts the amino acid tyrosine into phenylalanine.

2. The affected individual makes an enzyme that converts the amino acid tyrosine into phenylalanine.

3. The affected individual makes an enzyme that converts the amino acid phenylalanine into tyrosine.

4. The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine.

Monosomy means:
1. Lack of one pair of chromosomes
2. Lack of one of any one pair of chromosome
3. Presence of an extra chromosome
4. Presence of an extra set of chromosomes

Mendelian disorders are mainly determined by:
1. Alteration or mutation in a single gene.
2. Chromosomal gross structural changes.
3. Recombination between linked genes.
4. Jumping genes

‘When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters’. This is the statement of:

1. Law of Dominance

2. Law of segregation

3. Law of Independent Assortment

4. Law of Linkage

Occasionally, a single gene product may produce more than one effect. Such a gene is said to be:
1. Pleiotropic

2. Polygenic

3. Psuedoallele

4. Housekeeping

What is the F₂ phenotypic ratio in cases of incomplete dominance?
1. 1 : 1

2. 3 : 1

3. 1 : 2 : 1

4. 1 : 1

A heterozygous plant produces:
1. Only one kind of gamete

2. Two kinds of gametes each having one allele with equal proportion.

3. Two kinds of gametes each having two alleles with equal proportion.

4. Two kinds of gametes each having one allele with one allele occurring in more gametes than the other.

Assertion: Dominance is not always an autonomous feature of gene or its product.

Reason: Occasionally a single gene product may produce more than one effects.

What is the genetic disorder in which an individual has an overall masculine development gynaecomastia, and is sterile?
1. Down's syndrome
2. Turner's syndrome
3. Klinefelter's syndrome
4. Edward syndrome