ALLERGIC REACTIONS An allergy is a hypersensitive reaction to an antigen by the body. The antibody reacts with the antigen violently. People with allergies are oversensitive to foreign materials like dust, pollen grains, some foods, some drugs and some air pollutants. Allergic reactions lead to production of histamine by the body. Histamine causes swelling and […]
ALLERGIC REACTIONS Read More »
IMPORTANCE OF VACCINATION A vaccine is made of attenuated, dead or non¬virulent micro-organism that stimulate cells in the immune system to recognise and attack disease causing agent through production of antibodies. Vaccination protects individuals from infections of many diseases like smallpox, tuberculosis and poliomyelitis. Diseases like smallpox, tuberculosis and tetanus were killer diseases but this
IMPORTANCE OF VACCINATION Read More »
ABO BLOOD GROUPS There are four types of blood groups in human beings: A, B, AB and O. These are based on types of proteins on the cell membrane of red blood cells. There are two types of proteins denoted by the letters A and B which are antigens. In the plasma are antibodies specific
IMMUNE RESPONSES Immune response is the production of antibodies in response to antigens. An antigen is any foreign material or organism that is introduced into the body and causes the production of antibodies. Antigens are protein in nature. An antibody is a protein whose structure is complementary to the antigen. This means that a specific
STRUCTURE AND FUNCTION OF BLOOD Composition of Blood The mammalian blood is made up of fluid medium called plasma with substances dissolved in it. Cellular components suspended in plasma include; Erythrocytes (red blood cells), Leucocytes (white blood cells) Thrombocytes (platelets) Blood proteins. Plasma This is a pale yellow fluid consisting of 90% water. There
STRUCTURE AND FUNCTION OF BLOOD Read More »
TRANSPIRATION Transpiration is the process by which plants lose water in the form of water vapour into the atmosphere. Water is lost through stomata, cuticle and lenticels. Stomatal transpiration: This accounts for 80-90% of the total transpiration in plants. Stomata are found on the leaves. Cuticular transpiration: The cuticle is found on the leaves,
INTRODUCTION TO TRANSPORTATION Transport is the movement of substances within an organism. All living cells require oxygen and food for various metabolic processes. These substances must be transported to the cells. Metabolic processes in the cells produce excretory products which should be eliminated before they accumulate. The excretory products should be transported to sites of
INTRODUCTION TO TRANSPORTATION Read More »
DIGESTIVE SYSTEM AND DIGESTION IN HUMANS Organs that are involved with feeding in humans constitute the digestive system Digestive System and Associated Glands Human digestive system starts at the mouth and ends at the anus. This is the alimentary canal. Digestion takes place inside the lumen of the alimentary canal. The epithelial wall that faces the
DIGESTIVE SYSTEM AND DIGESTION IN HUMANS Read More »