Different colours of human skin depend on a pigment named melanin. Melanin is produced by melanocyte cells in the skin. The type and quantity of pigment in the skin of a person also depends on heredity/ genetic factors. The skin colour is also affected by climate. For example, people living in hot climates are of

Hair is the fastest growing tissue in the body. Different people have different types of hair. Some have straight hair, some have wavy while some have curly hair. If a strand of hair is cut and observed under the microscope, we observe that hair has a definite shape. Whether the hair is curly or straight

Voice is produced with the help of three components in the body that are the vocal cords, breathing action of the nose, and the cavities of the throat, mouth and nose. The vocal cords, located in the voice box, present in the throat vibrate when a stream of air passes. When a boy grows, the

A person who has forgotten who he is, remembers nobody, and nothing from his past, not even his name, is said to be suffering from amnesia. Each one of us, sometimes faces emotional turmoil, such as hurt, anger, fright, disappointment, etc. There are different reactions to this like, crying, blushing, sweating, etc. Amnesia is a

Food is composed of components that give mixed sensations called taste. It is perceived by the taste buds, tiny wart-like bumps, present on the tongue. A person has around three thousand taste buds. The taste buds have numerous sensory cells that are renewed once a week. The four major taste sensations are sweet, salty, bitter

Haemoglobin is an iron-containing protein present in the blood. It carries oxygen from the lungs to the body tissues and then, carbon dioxide back from these tissues to the lungs. The iron in haemoglobin imparts red colour to blood. The normal range for haemoglobin is 12-16 gm/dL for females and 14-18 gm/dL for males. A

Polio is a condition in which a person is unable to walk properly. Other names for polio are infantile paralysis or acute poliomyelitis. It is a highly contagious viral disease, caused by poliovirus infection. It affects a human*s nervous system. The polio virus enters the body and travels to the spinal cord, and brain through

Invisible forms of life, called germs, are present in the air, soil, food and also in water. Many of them cause diseases or infections. The human body has an ability to fight the attack of germs naturally. This ability to fight is called immunity. Immunity can be categorised into innate immunity and acquired immunity. Innate

An antibody is a substance that is produced by our body to fight poisons or toxic foreign substances (antigens) which enter the body. They are protective proteins produced by the immune system. Their production begins when any foreign substance attacks our body and continues until all antigen molecules are removed. They provide immunity to the

Our mind stores and remembers things. This act of remembering something is called memory. In other words, the ability to remember past events, facts, habits, and skills is called memory. Memory has two components: short-term and long-term memory. Short-term memory lasts about 20-30 seconds at a time while long-term memory lasts for a long time.

Vitamins are an important group of substances found in food. The word ‘vita’ means life. They are necessary for healthy life. Our body needs them in tiny quantities to continue the vital processes of the body. Vitamins are either water-soluble or fat-soluble. Vitamins are named as A, B, C, D, etc. Vitamin A is found

Skin is the outer covering on the bodies of animals or human beings. It protects muscles, bones and the internal organs. As it is in direct contact with the environment, it protects the body from viruses, parasites, etc. Other functions of the skin are insulation, temperature regulation and sensation. It also supports the production of

Hallucinations are imaginary sensations created by the mind. They appear real. In this situation, people imagine some imaginary situations like, they see a person, an animal, or a thing that is not there. Sometimes, it can relate with imaginary tastes as well. Some of the common reasons for hallucinations are lack of sleep, mental illness,