Two pure lines of corn have mean cob lengths of 9 and 3 inches respectively. The polygenes involved in this trait all exhibit additive gene action. Crossing these two lines is expected to produce a progeny with mean cob length [in inches] of:

(1) 12.0

(2) 7.5

(3) 6.0

(4) 2.75

Diseases that are caused by the malfunction of a pleiotropic gene are:

Out of a pair of monozygotic twins, one develops hare lip and the other does not. This can be an example of the genetic phenomenon of:

The mapping of genes on chromosome was attempted by

(1) T. H. Morgan

(2) Walter Sutton

(3) Alfred Sturtevant

(4) Henking

Today ________ are extensively used as a _______ point in the sequencing of whole genome

(1) Pedigree charts, conclusive

(2) Genetic maps, starting

(3) Pedigree charts, starting

(4) Genetic maps, conclusive

The initial studies for sex determination were done over

(1) Plants

(2) Insects

(3) Humans

(4) Hen

The concept of X body was given by

(1) T. H. Morgan

(2) Walter Sutton

(3) Alfred Sturtevant

(4) Henking

Which of the following statements are correct regarding Chromosomal basis of sex determination?

(i) The mechanism of sex determination in insects is of XO type.

(ii) XX insect is female while XO insect is male.

(iii) The X chromosome is called sex chromosome because it was involved in sex determination.

(iv) Grasshopper has XY type of sex determination.

(v) Man has XX type of sex determination.

(1) (iv), (v)

(2) (i), (ii), (iii), (iv), (v)

(3) (i), (ii), (iii)

(4) (i), (iv), (v)

Among human males _______ chromosome is present but its counterpart is _____ and called ______ chromosome.

(1) Y, bigger, Z

(2) X, smaller, Z

(3) X, smaller, Y

(4) Z, bigger, X

In which of the following male heterogamety is not observed?

(1) Insects

(2) Birds

(3) Humans

(4) (1) and (2)