4276: Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called

(a) Keystone species
(b) Allopatric species
(c) Sympatric species
(d) Threatened species
4277: Which of the following pairs is correct?

(a) Mahatma Gandhi : Swaraj is my birth right

(b) Jawaharlal Nehru : Truth and nonviolence are my God

(c) Sardar Patel : Dilli Chalo

(d) Subhash Chandra Bose : Give me blood, I will give you freedom
4278: Assertion (A)

A Rainfall is scanty on the east of Western Ghats.

Reason (R)

The east of Western Ghats is on the lee side.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not the correct explanation of A

(c) A is true but R is false

(d) A is false but R is true
4279: ELISA test is prescribed for:

(a) AIDS

(b) Typhoid

(c) Polio

(d) Cancer
4280: Dehydration in the human body results due to loss of:

(a) Salts

(b) Water

(c) Vitamins

(d) Hormones