Principles of Inheritance and Variation

Haploids are more suitable for mutation studies than the diploids. This is because:

1. all mutations, whether dominant or recessive are expressed in haploids
2. mutagens penetrate in haploids more effectively than in diploids
3. haploids are reproductively more stable than diploids
4. haploids are more abundant in nature than diploids

A human male produces sperms with the genotypes AB, Ab, aB, and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?

1. AaBb
2. AABB
3. AaBB
4. AABb

In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in F1 generation?

1. 9 : 1
2. 3 : 1
3. 50 : 50
4. 1 : 3

Inheritance of skin colour in humans is an example of:

1. Chromosomal aberration
2. Polygenic inheritance
3. Codominance
4. Point mutation

In the hexaploid wheat, the haploid (n) and basic (x) numbers of chromosomes are:

1. n = 21 and x = 14
2. n = 21 and x = 21
3. n = 7 and x = 21
4. n = 21 and x = 7

A common test to find the genotype of a hybrid is by:-

1. Crossing of one F1 progeny with recessive parent
2. Crossing of one F2 progeny with female parent
3. Crossing of one F2 progeny with male parent
4. Studying the sexual behaviour of F1 progenies

Both sickle cell anemia and Huntington's chorea are-

1. Congenital disorders
2. Bacteria-related diseases
3. Virus-related diseases
4. Pollutant-induced disorders

Test cross involves-

1. Crossing between two F1 hybrids
2. Crossing the F1 hybrid with a double recessive genotype
3. Crossing between two genotypes with recessive trait
4. Crossing between two genotypes with dominant trait

If a colour blind woman marries a normal visioned man, their sons will be

1. All normal visioned
2. Three-fourths colourblind and one-fourth normal
3. One-half colourblind and one-half normal
4. All colourblind

Cri-du-chat syndrome in humans is caused by the-

1. Loss of half of the long arm of chromosome 5
2. Loss of half of the short arm of chromosome 5
3. Trisomy of 21st chromosome
4. Fertilization of an XX egg by a normal Y-bearing sperm