Q. No.The best example of pleiotropy is:
1.
Skin color
2.
Phenylketonuria
3.
Colour Blindness
4.
ABO Blood group
Represented below is the inheritance pattern of a certain type of traits in humans. Which one of the following conditions could be an example of this pattern?
| 1. | Sickle cell anemia | 2. | Haemophilia |  |
| 3. | Thalassemia | 4. | Phenylketonuria |
In antirrhinum, two plants with pink flowers were hybridized. The F1 plants produced red, pink, and white flowers in the proportion of 1 red, 2 pink and 1 white. What could be the genotype of the two plants used for hybridization? Red flower colour is determined by RR, and White by rr genes.
| 1. | RR | 2. | Rr |
| 3. | rr | 4. | rrrr |
Study the pedigree chart of a certain family given below and select the correct conclusion which can be drawn for the character:
| 1. | The parents could not have had a normal daughter for this character |
| 2. | The trait under study could not be colourblindness |
| 3. | The male parent is homozygous dominant |
| 4. | The female parent is heterozygous |
The fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of the chromosomal theory of inheritance by Morgan and his colleagues because:
| 1. | a single mating produces two young flies |
| 2. | smaller female is easily recognisable from a large male |
| 3. | it completes its life cycle in about two weeks |
| 4. | it reproduces parthenogenetically |
Test cross in plants or in Drosophila involves crossing:
1. between two genotypes with dominant trait
2. between two genotypes with recessive trait
3. between two F1 hybrids
4. the F1 hybrid with a double recessive genotype
The salivary gland chromosomes in the dipteran larva, are useful in gene mapping because:
| 1. | They have endoreduplication chromosomes |
| 2. | These are fused |
| 3. | These are easy to stain |
| 4. | These are much longer in size |
Haemophilia is more commonly seen in human males than in human females because:
| 1. | This disease is due to a Y-linked recessive mutation |
| 2. | This disease is due to an X-linked recessive mutation |
| 3. | This disease is due to an X-linked dominant mutation |
| 4. | A greater proportion of girls die in infancy |
A woman with 47 chromosomes, due to three copies of chromosome 21, is characterized by:
| 1. | Turner syndrome | 2. | Down syndrome |
| 3. | Superfemaleness | 4. | Triploidy |
If Mendel might have studied 7 pairs of characters in a plant with 12 chromosomes instead of 14 then:
| 1. | He could not discover an independent assortment |
| 2. | He might have discovered linkage |
| 3. | He might have discovered crossing over |
| 4. | He might have not observed dominance |
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