Question

The efficiency index of growth in plants represents

• A. total increase in growth per unit time
• B. the increase in number of cells only
• C. growth of a particular system only
• D. permanent change in the structure of cells only

Hint:

Efficiency index is the ability of a plant to produce new material, linked with the increase in growth per unit time.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Growth rate is the increase in growth per unit time. The efficiency index measures the ability of the plant to produce new plant material.

Step 2: Compare the options
Option B and option C restrict growth to cells only or to one system. Option D describes only permanent structural change.

Step 3: Match
The best description is the total increase in growth per unit time, option (A).

Final Answer:
The efficiency index represents the total increase in growth per unit time. \[ \boxed{\text{(A) }\text{total increase in growth per unit time}} \]