Grain colour in wheat is determined by three pairs of polygenes. Following the cross AABBCC (dark colour) X aabbcc (light colour), in F₂ generation what proportion of the progeny is likely to resemble either parent?

(1) None

(2) Less than 5 percent

(3) One third

(4) Half

XO-chromosomal abnormality in human beings causes

(1) Turner's syndrome

(2) Down's syndrome

(3) Kilnefelter's syndrome

(4) none of these.

If a homozygous red-flowered plant (dominant)is crossed with a homozygous white-flowered plant, the offsprings will be

(1) half-white flowered

(2) half red-flowered

(3) all white-flowered

(4) all red-flowered

Gene which suppresses other gene's activity but does not lie on the same locus is called as 

(1) epistatic

(2) supplemetary

(3) hypostatic

(4) codominant

How many genome types are present in a typical green plants cell?

(1) More than Five

(2) More than Ten

(3) Two

(4) Three

Percentage of recombination between A and B is 9%, A and C is 17%, B and C is 26%, then the arrangement of genes is 

(1) ABC

(2) ACB

(3) BCA

(4) BAC

Which of the following conditions represents a case of co-dominance genes?

(1) A gene expresses itself, suppressing the phenotypic effect of its alleles. 

(2) Genes that are similar in phenotypic effect when present separately, but when together interact to produce a different trait.

(3) Alleles, both of which interact to produce a  trait, which may or may not resemble either of the parental types.

(4) Alleles, each of which produces an independent effect in a heterozygous condition. 

Which of the following is correct ?

(1) Henking discovered the small Y-chromosome.

(2) Drosophila also shows XX-XY sex determination like human.

(3) Birds have ZZ-ZW sex determination, where females are ZZ and males are ZW.

(4) Grasshoppers show XX-XY sex determination. 

Which of the following is true for a recessive disease in family A and B?

(1) In family A, both the parents are homozygous recessive.

(2) In family B, both the parents are homozygous dominant.

(3) In family B, both the parents are heterozygous recessive.

(4) In family A, both the parents are heterozygous recessive. 

Which of the following occurs due to monosomy of sex chromosome?

1. Down's syndrome

2. Turner's syndrome

3. Haemophilia

4. Sickle cell anaemia