LIFE PROCESSES

TRANSPORT IN PLANTS Plants need many inorganic substance for their healthy growth. The plant body is made up of carbon, hydrogen and oxygen. They also need nitrogen and many salts. A plant obtains these substances by absorbing them for the soil through roots and transport them to other parts of the Body. At the same time, the food that is prepared by the leaves should also be transported from leaves to other parts of the plant body.

TRANSPORT SYSTEM IN ANIMALS When compared to plants, cellular activities in animals are more complex and hence they need materials in large quantities. Moreover, they are multicellular organisms with a complicated structure and they need a system which can transport material from one part to another.

TRANSPORT SYSTEM IN MAN The transport system in man includes blood, blood vessels and heart Blood: blood is a liquid connective tissue. It consists of a fluid matrix called plasma and solid constituents such as red blood corpuscles, white blood corpuscles and platelets.

PLASMA Plasma contains 90% of water, 8% of proteins and the remaining 2% constitutes hormones, food materials such as glucose, amino acids, fatty acids, glycerol, vitamins, salts & urea. Plasma is a light yellowish coloured fluid which transports materials easily from one part to another part of the body.

RED BLOOD CORPUSCLES They are spherical and disc shaped. They do not have nucleii, RBC are produced in bone marrow. In healthy individual there are about 5.4 million RBC in a cubic m.m of blood. RBC have an iron containing pigment called haemoglobin.

HUMAN HEART (in section) FUNCTIONING OF THE HEART: The heart is made up of strong caradiac muscles. The chambers of the heart by their rythmic contraction and relaxation create pressure required to maintain the flow of blood throughout the body.

Excretory system The excretory system of man includes two kidneys. The ureters that start from kidneys open into the sac like urinary bladder that collects the urine. The urinary bladder opens out side by urethra. kidneys are dark red, bean-shaped structures, located at the back of abdominal cavity one on either side of backbone.