Among fraternal twins, one baby is haemophilic while the baby's brother is normal. Which statement is true:
1.  Baby is male
2.  Baby is female
3.  Mother is heterozygous
4.  Mother is homozygous

Minor change in a gene's structure is called:
1.  Reversible mutation
2.  Point mutation
3.  Forward mutation
4.  Backward mutation

According to Mendelism which character is showing dominance:

1. Terminal position of the flower

2. Green colour in the seed coat

3. Wrinkled seed

4. Green pod colour

Which of the following is the correct match:

1. Down Syndrome = 21st Chromosome

2. Sickel cell anaemia = X – Chromosome

3. Haemophilia = Y – Chromosome

4. Parkinson Disease = X & Y Chromosomes

Change in the sequence of nucleotides in DNA is called:

1. Mutagen

2. Mutation

3. Recombination

4. Translation

Which of the following is the example of a sex-linked disease:

1. AIDS

2. Colour blindness

3. Syphilis

4. Gonorrhoea

A gene is said to be dominant if:

Mangolian idiots are due to trisomy in the 21^st chromosome is called:

1. Down's syndrome

2. Turner's syndrome

3. Kleinfelters syndrome

4. Triplex syndrome

In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klinefelter's syndrome in males. It proves:

The linkage map of the X-chromosome of fruitfly has 66 units, with yellow body gene (y) at one end and bobbed hair (b) gene at the other end. The recombination frequency between these two genes (y and b) should be:

1. 60%

2. > 50%

3. ≤ 50%

4. 100%