Question

Growth in length of a plant can be measured by .........................

• A. Clinostat
• B. Auxanometer
• C. Manometer
• D. Potometer

Answer 1

The correct option is B Auxanometer

Auxanometer is an instrument used to measure the growth of the plant in terms of length. In order to measure the growth, a thread is passed over a pulley ad one end of thread is tied to the tip of plant and other end is tied to the weight. There is a needle in the centre of the pulley which shows deflection as the growth of a plant. The deflection can be read on the graduated arc to know the increase in length of the plant.

A manometer is a device used to measure pressure and a simple manometer consists of a U-tube filled with a liquid mercury of high density.

A clinostat is a slowly rotating device to which a plant is attached so that it receives stimulus from all sides and is used to study tropism in plants. It is commonly used to grow plants and mimic the growth of plants in space.

A potometer is a device used to measure the rate of uptake of water by a leafy plant shoot. It is also known as transpirometer as the main reason for water uptake by a cut shoot is transpiration.

Thus, the correct answer is option B.