Q. No.Genes that code for a pair of contrasting traits or slightly different forms of the same gene are known as:
1.
Alleles
2.
Loci
3.
Cistrons
4.
Introns
The two alleles of a gene pair are located on:
| 1. | The same chromosome. |
| 2. | Different chromosomes. |
| 3. | Homologous sites on homologous chromosomes. |
| 4. | Homologous sites on heterologous chromosomes. |
Morgan, in his experiment on fruit flies, found that the genes white and yellow were very tightly linked and showed:
| 1. | 50 % recombination | 2. | 37.2 % recombination |
| 3. | 12.5 % recombination | 4. | 1.3 % recombination |
What is the mode of inheritance of phenylketonuria?
| 1. | Autosomal recessive | 2. | Autosomal dominant |
| 3. | Sex linked recessive | 4. | Sex linked dominant |
Which of the following is not a feature of Down’s Syndrome?
| 1. | It is caused by a non-disjunction in an autosome. |
| 2. | The affected individual has a trisomy of chromosome 21. |
| 3. | The affected individual has a characteristic simian palmar crease. |
| 4. | The mental development of the affected individual is normal. |
Pedigree analysis is used for genetic analysis in humans rather than conventional genetic methods because:
| I: | Choice matings are not possible. |
| II: | The number of progeny is limited. |
Of the two statements:
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
A plant with the genotype Tt should be called:
| 1. | Heterologous | 2. | Hemizygous |
| 3. | Heterozygous | 4. | Dihybrid |
What is F2 phenotypic ratio in a dihybrid cross?
| 1. | 1 : 1 | 2. | 3 : 1 |
| 3. | 9 : 3 : 3 : 1 | 4. | 1 : 1 : 1: 1 |
In cases of Phenylketonuria:
| 1. | The affected individual lacks an enzyme that converts the amino acid tyrosine into phenylalanine. |
| 2. | The affected individual makes an enzyme that converts the amino acid tyrosine into phenylalanine. |
| 3. | The affected individual makes an enzyme that converts the amino acid phenylalanine into tyrosine. |
| 4. | The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine. |
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