Among the following characters, which one was not considered by Mendel in his experiments on pea?

(1) Stem - Tall or Dwarf

(2) Trichomes - Glandular or Non-glandular

(3) Seed - Green or Yellow

(4) Pod - Inflated or Constricted

Thalassemia and sickle-cell anaemia are caused due to a problem in globin molecule synthesis. Select the correct statement.

(1) Both are due to a qualitative defect in globin chain synthesis

(2) Both are due to a quantitative defect globin chain synthesis

(3) Thalassemia is due to less synthesis of globin molecules

(4) Sickle-cells anaemia is due to a quantitative problem of globin molecules

A disease caused by an autosomal primary non-disjunction is 

(1) Down's syndrone

(2) Kilnerfelter's syndrome

(3) Turner's syndrome

(4) Sickle-cell anemia

The mechanism that causes a gene to move from one linkage group to another is called 

(1) inversion

(2) duplication

(3) translocation

(4) crossing-over

If a colourblind man marries a woman who is homozygous for normal colour vision, the probalility of their son being colourblind is 

(1) 0

(2) 0.5

(3) 0.75

(4) 1

A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F₁ plants were selfed the resulting genotypes were in the ratio of 

(1) 1 : 2 : 1 :: Tall heterozygous : tall homozygous : Dwarf

(2) 3 : 1 :: Tall : Dwarf

(3) 3 : 1 :: Dwarf : Tall

(4) 1 : 2 : 1 :: Tall homozygous : Tall heterogygous : Dwarf

Pick out the correct statements.

I. Haemophilia is a sex-linked recessive disease

II. Down's syndrome is due to aneuploidy.

III. Phenylketonuria is an autosomal recessive gene disorder

IV. Sickle cell anaemia is an x - linked recessive gene disorder

(1) II and IV are correct

(2) I, III and IV are correct

(3) I, II and III are correct

(4) I and IV are correct

In a test cross involving F₁ dihybrid flies, more parental-type offspring were produced than the recombinant type offspring. This indicates

(1) chromosomes failed to separate during meiosis 

(2) the two genes are linked and present on the same chromosome

(3) both of the characters are controlled by more than one gene

(4) the two genes are located on two different chromosomes

Match the terms in Column I with their description in Column II and choose the correct option.

Codes : 

Which of the following most appropriately describes haemophilia?

(1) X-linked recessive gene disorder

(2) Choromosomal disorder

(3) dominant gene disorder

(4) Recessive gene disorder