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 |
A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters are affected. Which of the following mode of inheritance might be the reason for this disease?
1. Sex-limited recessive
2. Autosomal dominant
3. Sex-linked recessive
4. Sex-linked dominant
Genes for cytoplasmic male sterility in plants are generally located in:
1. Nuclear genome
2. Chloroplast genome
3. Cytosol
4. Mitochondrial genome
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 |
AA Bb Cc genotypes form how many types of gametes?
1. 4
2. 8
3. 2
4. 6
If a female having gene for haemophilia and colour-blindness on one X-chromosome marries a normal male, then what are the chances in their offspring?
1. 50% sons diseased and 50% normal
2. All normal offspring
3. 100% daughters are carrier
4. 100% sons diseased
First child of a normal male and female is albino, what are the chances of second child being albino:
1. 25%
2. 50%
3. 75%
4. 100%
Point mutation is induced by:
1. Adenine
2. Guanine
3. 3-cytosine
4. 5-bromouracil
Reason for trisomy in Down's syndrome is:
1. Non-disjunction during sperm formation
2. Non-disjunction during egg formation
3. Non-disjunction at the time of egg or sperm formation
4. Addition of one extra chromosome during mitosis