Question

Auxanometer is required for
A. Studying rate of transpiration
B. Measuring rate of respiration
C. Finding out rate of photosynthesis
D. Calculating rate of growth

Answer 1

Plants are one of the most important components of the living world and they are known as the producers as they are able to manufacture their own food in the form of simple sugars from the inorganic raw materials. Most of the species of plants are able to grow throughout their lives.

Complete step by step answer: In plants, the process of growth occurs throughout their complete lives and the growth is through the combination of cell growth and cell division. The process of cell division occurs through the process of mitosis and it causes an increase in the number of cells. The cell's growth helps to increase the cell size. These two types of cell growth helps and brings about growth in the plants. The plant growth occurs through the agency of meristem which contains undifferentiated cells that can continue to divide and aid in the growth as well as replacement of old tissues by the plant. Mostly in plants, the growth occurs in the shoot region which increases in length to certain period.
The growth rate of a plant can be measured by using an instrument known as the auxanometer. It is also known as an arc indicator. An auxanometer is used to calculate the growth rate or rate of growth of a plant by measuring the increase in the growth in plants. The auxanometer is present in two types of variations which are the arc- auxanometer and the sensitive auxanometer.
The arc auxanometer consists of a wire fixed with the apex of the plant on one of its ends and on the other end a dead weight is placed. This arrangement is passed over a pulley which has a pointer attached to it. In case of growth of the plant, the plant height increases. When the height of the plant increases, the pulley rotates and causes the pointer to move on a circular scale. This directly gives the magnitude of the growth. The rate of growth is calculated by dividing the observed growth length by the time period of the measurement.
The sensitive auxano meters are able to measure even small growth as in micrometers. The measurement in smallest changes allows to measure the growth for short term changes.
In order to measure and study the rate of respiration in plants, a potometer is used. The potometer measures the rate of respiration due to factors such as light, temperature, humidity etc. The rate of photosynthesis is deduced by using a photosynthesis meter system.
Therefore, the correct option is option D.

Note: The growth of a plant is an important attribute of its life cycle. Majority of the plants grow throughout their life period and the rate of growth is slow or may be fast. An auxanometer is used as an instrument to measure and calculate the rate of plant growth over a period of time. The growth in plants is affected by various environmental conditions such as light, humidity, water, soil as well as other environmental conditions such as temperature etc.