171: Which of the following is/are used as biofertilizers ?
I. Azolla
II. Blue-green algae
III. Alfalfa.
Select the correct answer using the codes given below.
Codes:
(a) II alone
(b) I and II
(c) I and III
(d) I, II and III
172: Ultrafiltering units of kidney are known as:
(a) Nephron
(b) Glomerulus
(c) Vena Cava
(d) Tubule
173: A person has 4 coins each of different denomination. What is the number of different sums of money the person can form (using one or more coins at a time)?
(A) 15
(B) 16
(C) 10
(D) 12
174: Neolithic period of age is not characterised by:
(a) Agriculture
(b) Use of copper
(c) Domestication of animals
(d) Fishing
175: Eco mark is given to the Indian products that are
(a) pure and unadulterated
(b) rich in proteins
(c) environment friendly
(d) economically viable