Q. No.When Morgan hybridised yellow-bodied, white-eyed females to brown-bodied, red-eyed males and intercrossed their F1 progeny, the F2 ratio deviated very significantly from the 9:3:3:1 ratio. this can be attributed to the fact that:
1. The genes are located on X and Y chromosomes
2. Fruit fly has abnormal chromosomes
3. The genes are located on the X chromosome
4. The genes exhibit incomplete dominance
The two alleles of a gene pair are located on:
1. Homologous sites on homologous chromosomes
2. Heterologous sites on homologous chromosomes
3. Homologous sites on heterologous chromosomes
4. Heterologous sites on heretologous chromosomes
Which one of the following is the most suitable, medium for culture of Drosophila melanogaster ?
(1) Moist bread
(2) Agar agar
(3) Ripe banana
(4) Cow dung
When the two genes in a dihybrid cross are situated on the same chromosome:
1. The proportion of parental gene combinations was much higher than the non-parental type.
2. The proportion of parental gene combinations was much lesser than the non-parental type.
3. The proportion of parental gene combinations was equal to the non-parental type.
4. Only recombinants are formed.
1. discovery of genes
2. Principle of linkage
3. Chromosome theory of heredity
4. Rediscovery of Mendelism
A diploid cell containing 10 chromosomes undergoes meiosis. How many chromosomes
are present in the cell after meiosis II?
(1) 2
(2) 5
(3) 10
(4) 15
| Column-I | Column-II | |
| 1. | De Vries, Correns, Tschermak | Disproved Mendel’s law of Independent Assortment |
| 2. | Sutton and Boveri | Gave the chromosomal theory of inheritance |
| 3. | Alfred Sturtevant | Developed the first genetic map |
| 4. | T. H. Morgan | Discovery of the white-eyed mutation in the fruit fly |
| List I | List II |
| A. Mendelian Disorder | I. Chromosomal Theory of inheritance |
| B. Alfred Sturtevant | II. Klinefelter's syndrome |
| C. Chromosomal Disorder | III. Cystic fibrosis |
| D. Sutton and Boveri | IV. Used the frequency of recombination between the gene pair in the same chromosome |
Choose the correct answer from the options given below:
1. A-III B-I C-II D-IV
2. A-III B- IV C-II D-I
3. A-IV B-III C-II D-I
4. A-II B-III C-I D-IV
| 1. Segregation | 2. Independent assortment |
| 3. Multiple allelism | 4. Pleiotropy |
| Statement I | If two genes are located on heterologous chromosomes they will assort independently and a dihybrid cross will yield a F2 phenotypic ratio of 9: 3: 3: 1. |
| Statement II | If the two genes are linked the dihybrid F2 phenotypic ratio will vary significantly from 9: 3: 3: 1 with strength of linkage directly proportional to the distance between the genes. |
1. Statement I is correct; Statement II is incorrect
2. Statement I is incorrect; Statement II is incorrect
3. Statement I is correct; Statement II is correct
4. Statement I is incorrect; Statement II is correct
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