Principles of Inheritance and Variation · Question 38

If a female individual is with small round head, furrowed tongue, partially open mouth and broad palm with characteristic palm crease. Also the physical, psychomotor and mental development is retarded. The karyotype analysis of such an individual will show :

1. Trisomy of chromosome 21
2. 47 chromosomes with XXY sex chromosomes
3. 45 chromosomes with XO sex chromosomes
4. 47 chromosomes with XYY sex chromosomes

Select the incorrect match regarding the symbols used in the Pedigree analysis:

1. [figure] – Parent with male child affected with disease
2. [figure] – Sex unspecified
3. [figure] – Affected individual
4. [figure] – Consanguineous mating

A normal girl, whose mother is haemophilic marries a male with no ancestral history of haemophilia. What will be the possible phenotypes of the offspring? Choose the most appropriate answer from the options given below:

1. B and D only
2. A and B only
3. B and C only
4. A and D only

The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called :

1. Net square
2. Bullet square
3. Punch square
4. Punnett square

In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

1. 100%
2. 50%
3. 75%
4. 25%

Experimental verification of the chromosomal theory of inheritance was done by

1. Sutton
2. Mendel
3. Morgan
4. Boveri

Select the correct match

1. Thalassemia – X linked
2. Sickle cell anaemia – Autosomal recessive trait, chromosome-11
3. Phenylketonuria – Autosomal dominant trait
4. Haemophilia – Y linked

Identify the wrong statement with reference to the gene ‘I’ that controls ABO blood groups.

1. Allele ‘i’ does not produce any sugar.
2. The gene (I) has three alleles.
3. When IA and IB are present together, they express same type of sugar.
4. A person will have only two of the three alleles.

How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits?

1. 14
2. 4
3. 2
4. 8

The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by :

1. Alfred Sturtevant
2. Gregor J. Mendel
3. Sutton Boveri
4. T.H. Morgan