Inheritance of skin colour in humans is an example of

• chromosomal aberration

• point mutation

• polygenic inheritance

• polygenic inheritance

Two genes R and Y are located very close on the chromosomal linkage map of a maize plant. When RRYY and rryy genotypes are hybridised, the F₂ segregation will show:

• higher number of the recombinant types.

• segregation in the expected 9 : 3 : 3 : 1 ratio

• segregation in 3 : 1 ratio

• segregation in 3 : 1 ratio

193.

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

• crossing of one F₂ progeny with male parent

• crossing of one F₂ progeny with female parent

• studying the sexual behaviour of F₁ progenies

• studying the sexual behaviour of F₁ progenies

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?

• 50:50

• 9:1

• 1:3

• 1:3

Which one of the following is the most suitable, medium for culture of Drosophila melanogaster?

• Moist bread

• Agar agar

• Ripe banana

• Ripe banana

Phenotype of an organism is the result of

• mutations and linkages

• cytoplasmic effects and nutrition

• environmental changes and sexual dimorphism

• environmental changes and sexual dimorphism

Which one of the following is an example of polygenic inheritance?

• Flower colour in Mirabilis jalapa

• Production of male honey bee

• Pod shape in garden pea

• Pod shape in garden pea

In Mendel's experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F₂ generation of the cross RRYY x rryy?

• Only round seeds with green cotyledons

• Only wrinkled seeds with yellow cotyledons

• Only wrinkled seeds with green cotyledons

• Only wrinkled seeds with green cotyledons

One gene – one enzyme hypothesis was postulated by

• R. Franklin

• Hershey and Chase

• A. Garrod

• A. Garrod

Test cross involves

• crossing between two genotypes with recessive trait

• crossing between two F₁ hybrids

• crossing the F₁ hybrid with a double recessive genotype

• crossing the F₁ hybrid with a double recessive genotype