Question

Auxanometer is used to measure
A. Length
B. Respiration
C. Transpiration
D. Ascent of sap

Answer 1

Hint:- Growth of a plant is a quantitative phenomenon that can be measured in relation to time. It can be measured in terms of the increase in length or height, increase in area or volume and increase in the number of cells.

Complete step-by-step solution:-
An auxanometer is an instrument used for measuring the increase in plant growth. It can be used to calculate the growth rate of plant shoots (length). In the case of an arc-auxanometer, the wire is fixed on one end with a plant apex and on the other end with a dead weight. It passes over a pulley that is joined to a pointer. As the height of the plant increases, the pulley rotates and the pointer moves on a circular scale to precisely give the magnitude of growth. The "growth rate" is a derived estimate obtained by dividing the auxanometer 's calculated growth length by the time the measurement was taken.
Responsive auxanometer makes it possible to quantify growth as small as a micrometer, allowing growth to be measured in response to short-term changes in atmospheric composition. In the laboratory, the field and the school, auxanometers are used. It is often called an arc-indicator.
So, the correct answer is option (A).

Note:- Another device used to measure changes in plant growth is crescograph. This device was invented by an Indian botanist and biologist, Sir Jagadish Chandra Bose. The two significant things used in the instrument are the smoked glass plate and the number of clockwise gears. There are regular markings on the plate and the clockwise gears are used to measure the growth that is affected by various conditions.