In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klinefelter's syndrome in males. It proves:
1. | In human beings, the Y chromosome is active in sex determination. |
2. | Y chromosome is active in sex determination in both human beings and Drosophila. |
3. | In Drosophila Y-chromosome decides femaleness. |
4. | The Y chromosome of man has genes for the syndrome. |
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%
Which one of the following traits of garden peas studied by Mendel was a recessive feature?
1. | Axial flower position |
2. | Green seed colour |
3. | Green pod colour |
4. | Round seed shape |
When a cluster of genes shows linkage behaviour they:
1. Do not show a chromosome map
2. Show recombination during meiosis
3. Do not show independent assortment
4. Induce cell division
A genetic map is one that:
1. Establishes sites of the genes on a chromosome
2. Establishes the various stages in gene evolution
3. Shows the stages during the cell division
4. Shows the distribution of various species in a region
Independent assortment of genes does not take place when:
1. | Genes are located on homologous chromosomes |
2. | Genes are linked and located on the same chromosome |
3. | Genes are located on non-homologous chromosome |
4. | All the above |
When dominant and recessive alleles express themselves together it is called:
1. Co-dominance
2. Dominance
3. Amphidominance
4. Pseudo dominance
The probability of four sons to a couple is:
1. | 1/4 | 2. | 1/8 |
3. | 1/16 | 4. | 1/32 |
Sickle cell anaemia is due to:
1. | Change of Amino Acid in α-chain of Haemoglobin. |
2. | Change of Amino Acid in β-chain of Haemoglobin. |
3. | Change of Amino acid in both α and β chains of Haemoglobin. |
4. | Change of Amino acid either α or β chain of Haemoglobin. |
Mangolian idiots are due to trisomy in the 21st chromosome is called:
1. Down's syndrome
2. Turner's syndrome
3. Kleinfelters syndrome
4. Triplex syndrome