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

In angiosperms, microsporogenesis and megasporogenesis

(1) occur in anther

(2) form gametes without further divisions

(3) involve meiosis

(4) occur in ovule

Destruction of the anterior horn cells of the spinal cord would result in loss of 

(1) sensory impulses

(2) voluntary motor impulses

(3) commissural impulses

(4) integrating impulses

The cutting of DNA at specific locations became possible with the discovery of 

(1) restriction enzymes

(2) probes

(3) selectable markets

(4) ligases

The enzyme that is not present in succus entericus is

(1) maltase

(2) nucleases

(3) nucleosidase

(4) lipase

In which of the following interactions both partners are adversely affected?

(1) Competition

(2) Predation

(3) Parasitism

(4) Mutualism

Codes