Question

Answer briefly.

(1) Explain the process of translocation in plants.

(2) Explain the structure and function of a nephron

Answer 1

(1) The transportation of food from the leaves to other parts of the plant occurs in the vascular tissue, namely the phloem. This process of transporting food is known as translocation.

The phloem consists of companion cells, sieve tubes, phloem parenchyma and fibres. The translocation of food occurs in the sieve tubes with the help of companion cells.

Translocation in the phloem is bidirectional and achieved by utilizing energy from ATP. For example, a food material such as sucrose is transported into the phloem tissue using ATP energy. As a result, the osmotic pressure in the tissue increases, causing the water to move into it. This pressure moves the material in the phloem to the tissues, which have less pressure. This is helpful in moving materials according to the requirements of the plant.

(2) Structure: The main components of a nephron are the glomerulus, Bowman’s capsule, and a long renal tube. Each nephron has a cup-shaped, thin-walled structure present at the upper end called Bowman's capsule. It contains a tuft of blood capillaries called glomerulus.

Structure of a Nephron

Functions:

• The glomerular capillaries of nephron carry out the function of filtration of blood having nitrogenous waste in the form of urea after every 4.5 minutes and form an ultrafilterate.

• The walls of Bowman’s capsule are semi permeable and they allow water and other small molecules to pass through them from the ultra filtrate and form glomerular filtrate.

• The long renal tube of nephron carries out the important function of reabsorption and secretion of essential ions. Therefore this helps in maintaining the constant pH within the n body.

It is due to the well functioning of neutrons which has enabled humans to excrete nitrogenous wastes with a minimal loss of water so that they can lead a successful terrestrial life.