CHAPTER 5 TRANSPORTATION IN ANIMALS AND PLANTS
TRANSPORTATION IN ANIMALS
The function of the circulatory system is to transport the substances to and from the various organs of the body.
Blood is the medium through which all substances are transported.
The fluid part of the blood is known as ‘plasma’. The cells which contain the red pigment are called ‘red blood cells’ and the red pigment itself is called ’haemoglobin’ which facilitates the transport of oxygen. The blood also contains ‘white blood cells’ which protect the body against diseases. Blood also has ‘platelets’ which are responsible for clotting of blood in case of injuries.
Arteries carry oxygen- rich blood from the heart to the other parts of the body.
Veins carry carbon dioxide- rich blood from the body to the heart for purification.
Heart is the most vital organ of the body. It pumps blood to various parts of the body. The heart has four chambers. The upper two chambers are the atrium and the two lower chambers are the ventricles
The process of removal of waste from the body is called excretion. All the parts involved in this process form the excretory system. The liquid wastes are produced when the kidneys filter out the blood and store the waste in the urinary bladder. This waste is then passed out in the form of urine.
TRANSPORTATION IN PLANTS
Plants absorb water through the roots. There is a vascular tissue called xylem through which nutrients and water are transported to the entire plant. The vascular tissue that transports food to the entire plant is called phloem.
Water is absorbed by the plant because of transpiration. Transpiration is when the leaves of the plant lose water through evaporation. Due to this loss of water a suction pull is created and the water is pulled up through the roots.