A character, which is expressed in a hybrid is called

• dominant

• co-dominant

• recessive

• epistaticn

Which of the following is correct

• Haemophilic-Y-chromosome

• Down's syndrome-21' chromosome

• Sickle cell anaemiaX-chromosome

• Parkinson's disease-X and Y-chromosome

Test cross is a cross between

• hybrid and dominant parent

• hybrid and recessive parent

• two hybrid parents

• two distantly related species

Which of the following condition is called monosomic?

• 2n + 1

• 2n + 2

• n + 1

• 2n - 1

What is a test cross? Why is it so named?

Polyploid derived from two different species is called

• autopolyploid

• triploid

• allopolyploid

• monoploid

197.

The gene of sickle cell anaemia is inherited by

• blood cells

• bone cells

• sex chromosomes

• autosomes

How many pairs of contrasting characters in pea pod were chosen by Mendel?

• 3

• 5

• 7

• 9

If a cross between two individuals produces offsprings with 50% dominant character (A) and 50% recessive character (a) the genotype of parents are

• Aa $\times$Aa

• Aa $\times$aa

• AA $\times$aa

• AA $\times$Aa

Which pairs of the following diseases are caused by two genes located on human X-chromosomes?

• Colour blindness and phenylketonuria

• Colour blindness and haemophilia

• Colour blindness and albinism

• Colour blindness and hypertrichosis