Question

Match List-I with List-II

List-I	List-II
(A) Propagation of starter culture	(I) Horral-Elliker test
(B) Bacteriophage	(II) Conjugation
(C) Cheese starter	(III) Calcium ions
(D) Plasmid	(IV) Burst size

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (II), (B) - (I), (C) - (III), (D) - (IV)
• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Remember that "burst size" is always associated with viral/phage replication cycles, and "conjugation" is a classic plasmid-mediated transfer mechanism. These two matches help quickly identify the correct option.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This matching question is based on the biochemical, genetic, and quality control parameters involved in dairy starter cultures and bacteriophage control.
Detailed Explanation:
Let us match each item in List-I with its corresponding description in List-II:
- (A). Propagation of starter culture matches with (III). Calcium ions: Bacteriophages require divalent calcium ions (\(\text{Ca}^{2+}\)) for adsorption onto the bacterial cell wall. To propagate lactic starter cultures without phage contamination, plants use phage-resistant media (PRM) containing phosphate salts. These salts bind and chelate calcium, making propagation phage-resistant.
- (B). Bacteriophage matches with (IV). Burst size: The burst size is a quantitative parameter of the lytic cycle of a bacteriophage, representing the average number of virions released per infected host cell upon lysis.
- (C). Cheese starter matches with (I). Horral-Elliker test: The Horral-Elliker test is a classic activity assay used to measure the rate of acid production by lactic starter cultures under standardized conditions.
- (D). Plasmid matches with (II). Conjugation: Plasmids in lactic acid bacteria (which encode traits like lactose metabolism and protease activity) are often conjugative, meaning they can be transferred between cells via conjugation.
This gives the match: (A) - (III), (B) - (IV), (C) - (I), (D) - (II).
Final Answer:
The correct matching sequence is (A) - (III), (B) - (IV), (C) - (I), (D) - (II). Hence, the correct option is (D).