Mental retardation is associated with

(1) Klinefelter’s syndrome

(2) Haemophilia

(3) Cystic fibrosis

(4) Phenylketonuria

Study the pedigree chart given below to identify the disorder

(1) Sickle cell anaemia

(2) Haemophilia

(3) Myotonic dystrophy

(4) Phenylketonuria

What does the given pedigree chart shows? 

(1) Sex-linked recessive trait

(2) Sex-linked dominant trait

(3) Inheritance of Sickle cell anaemia

(4) Inheritance of autosomal dominant trait

Which of the following statements are correct with respect to aneuploidy? 

(i) Aneuploidy is caused due to failure of segregation of chromatids

(ii) Aneuploidy is caused by due to failure of segregation of alleles

(iii) Aneuploidy results into loss or gain of chromosomes.

(iv) Aneuploidy always results into gain of chromosomes.

(v). Down’s syndrome is caused due to aneuploidy in chromosome 21.

(1) (i), (iv) and (v)

(2) (ii), (iii) and (v)

(3) (i), (ii) and (iv)

(4) (i), (iii) and (v)

Which of the following statements are correct?

(i) Polyploidy is caused due to failure of cytokinesis after telophase.

(ii) polyploidy results into increase in number of autosomes

(iii) Turner’s syndrome is an example of polyploidy

(iv) polyploidy results into an increase in a whole set of chromosomes

(1) (i) and (ii)

(2) (i) and (iii)

(3) (ii) and (iii)

(4) (i) and (iv)

Sex determination in Honey bee depends upon-

(1) Number of sets of chromosomes present in parents

(2) Number of sets of chromosomes present in progenies

(3) Number of sets of genes present in parents

(4) Number of sets of genes present in progenies

What is wrong with respect to sex determination in honey bee?

(1) Unfertilized egg develops as a male by means of parthenogenesis.

(2) Union of sperm and egg develops as a female

(3) All workers and males will have 16 chromosomes while queen will have 32 chromosomes.

(4) Males produce sperms by mitosis.

What is the special characteristic feature of haplodiploid sex determination?

1. Males produce sperms by mitosis

2. Number of sets of chromosomes present in progenies will decide their sex

3. Workers will have diploid set of chromosomes.

4. Drones will have haploid set of chromosome.

Colour Blindness is ------- due to defect in either----- or---- ------ of eye.

1. Sex-linked recessive disorder, red, orange rods
2. Sex-linked dominant disorder, red, green rods
3. Sex-linked dominant disorder, red orange cones
4. Sex-linked recessive disorder, red , green cones

In case of Pea plant, grey seed colour (G) is dominant to white (g). If the progenies are formed in the following phenotypic ratio, find the genotypes of parents.

Grey was crossed with white, 49 grey and 54 white were formed. The genotype of the grey parent will be

    1) Gg

    2) GG

    3) gg

    4) None of these