Question

Which of the following is used to determine the rate of transpiration in plants?
A. Hygrometer
B. Potometer
C. Auxanometer
D. Barometer

Answer 1

The process of movement of water through a plant and leading to the evaporation of water from the leaves is known as transpiration. The evaporation of water takes place through the aerial parts of the plants such as shoots, leaves and also the flowers. The process of water taken up and lost by the plant is an important aspect and is maintained at a particular rate depending on the habitat of the plant.

Complete answer:
Water is an important factor that is required by the plants for carrying out the various processes especially the photosynthetic process. The roots take up water from the soil and it reaches the leaves through different conducting tissues. In this process, some amount of water is used by the plant but most of it is lost to the environment through the process of transpiration.
Transpiration can be explained as the removal of excess water from the parts of the shoot system that is present above the ground levels. The process of transpiration takes place when the water is lost in the form of water vapors, from the leaves and shoots. The stomata allows the diffusion of gases such as carbon dioxide and oxygen and the opening of the stomata causes the water present near the surface of leaves to be lost to the environment.
The amount of water lost by the plants in the form of water vapors over a time period is known as rate of transpiration of plants. The rate of transpiration depends upon the opening and closing of the stomatal pores. Various environmental factors can be also responsible for the rate of transpiration. The rate of transpiration is measured by using a potometer. A photometer is used to measure the rate of transpiration which is proportional to the water up taken by the plant.
Hygrometers are used to measure the amount of water vapor or humidity in the atmosphere especially in the air, soil as well as in confined areas. It is also a meteorological instrument.
An apparatus used for measuring the increase in the growth rate of the plants is known as an auxanometer. It is also known as an arc indicator. The name auxanometer indicates auxin and meter as auxin stands for growth and meter is the measure of growth.
A scientific instrument that is employed to measure the air pressure in the environment is known as a barometer. It is used for the purpose of measuring atmospheric pressure.

Therefore, the correct option is option B.

Note: Transpiration is an important phenomenon of plants and in this process due to the regular opening and closing of the stomata water from the surfaces of plants as water vapors. The rate of transpiration is measured by calculating the distance covered by an air bubble in a particular time inside a capillary tube. The photometer is an apparatus used to determine the rate of transpiration in plants.