Biotechnology, Structure of Teeth, Important Facts About Human Physiology

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The exploitation of biological processes for industrial and other purposes, esp. the genetic manipulation of microorganisms for the production of antibiotics, hormones, etc.


Biotechnology is the use of living organisms (especially microorganisms) in industrial, agricultural, medical and other technological applications.

Importance of Biotechnology

  • To increases production

  • To introduce improved quality of seeds and plants

  • To introduce plants resistant to disease and insect pests

  • To introduce verities suited to particular climates and soils.

  • To introduce verities resistant to lodging

  • To improve nutritional value of crops

  • To save rare varieties of plants by rapid clonal propagation for breeders to use in future.


  • The humans have two sets of teeth one replaced by the second. The primary set or milk or deciduous teeth are 20 in number while there are 32 permanent teeth in adults.

  • In children there are 20 deciduous or milk teeth. These are

    • Incisor:

    • Canine:

    • Premolars:

  • In adults there are 32 permanent teeth. In each jaw on each side there are:

    • Incisors:

    • Canines:

    • Premolars:

    • Molars:

  • Incisors: The central front teeth are called incisors. There are four in upper jaw and four in lower jaw.

  • Canines: The pointed, dark colored teeth on either side of the incisors are canines. 2 in upper jaw and 2 in lower jaw.

  • Premolars: These are bi-cusped teeth after the canines. There are 8 premolars. 4 in the upper jaw and 4 in the lower.

  • Molars: There are 12 molars, 6 in the upper jaw and 6 in the lower jaw.

Structure of Teeth

  • Each tooth consists of a crown which is the visible part and the root, which anchors it in sockets in the jaw. A tooth consists mainly of dentine. The crown is coated with even harder enamel, while the root is covered with cement urn to help another it in the jaw.

  • Inside each tooth, there is a cavity full of pulp, carrying nerves and the tooth’s blood and eats through the dentine to the pulp when the decay reaches the pulp, pain and inflammation follows and tooth may die.

  • A nerve, an artery, a vein and lymph duct enters the pulp cavity through the root canal. The nerves give sensation of hot and cold.


  • Antibody is a protein produced by white blood cells that help to destroy bacteria. Antibodies react with the antigens and inactivate or destroy them. A large number of antibodies are produced in blood which are targeted against various types of antigens.

  • Antigens are foreign molecules, cells, bacteria, viruses or fungi which enter the body usually a disease causing microorganisms. Antibodies are the integral part of the defence mechanism of human body. They are also involved in immunity against disease.


  • It is a disease in which the Peron have prolonged blood clotting time resulting in excessive bleeding fron injury.

  • It is due to the deficiency of vitamin K.

  • It is a semi lethal disease controlled by recessive gene.

  • It is less common in women than in men.

Important Facts About Human Physiology

  • The largest gland of the body: Liver

  • The largest organ of the body: Skin

  • The longest bone of the body: Femur

  • The total number of bones in the body: 206

  • The hardest bone of the body: Tooth

  • The smallest bone of the body: Stapes

  • Total number of muscles in the body: 600

  • The filter of the body: Kidney The pump of the Body: Heart

  • Total number of bones in vertebral column: 33

  • The normal body temperature: 98.4 F (37 C)

  • The normal respiratory rate of the Body: 16-18 per min

  • The total volume of blood in body: 4-5 litres

  • Total number of bones in face: 14 Vascular connection between foetus and uterus: Placenta


Human brain is contained in skull. It has three major parts.

  • The Cerebrum or bigger brain

  • The Cerebellum or Smaller brain

  • Medulla Oblongata or hind brain

  • The cerebrum constitutes the major volume of brain. It consists of two large masses of nervous material known as cerebral hemispheres. Human consciousness, thought, emotions, sight, will, hearing, sensation of pain, memory and speech are center in the cerebrum. Some parts of it also control motor nerves, operating the arms and legs.

  • The cerebellum or the smaller brain is related with the coordination of action of nerves and muscles. In this way movements of body are manged. Medulla or hind brain contains the centres for reflex actions in addition to automatic movements such as breathing and walking.

Reflex Action

  • Reflex actions are the response to environmental changes both internal and external and are immediate or automatic and are without intervention of will.

  • These reflexes Amy be simple or conditioned e.g. watering of mouth on seeing or smelling of food. - Simple reflexes are inborn, inherited or unlearnt responses to stimuli.

  • The structural and functional basis of simple reflex is called reflex arc.

  • Impulses are carried from receptors to sensory neurons to CNS from where they are passed on via motor neurons to the effectors for necessary response.


Substances (esp. synthetic resins) that become plastic on heating and harden on cooling and are able to repeat these processes


  • A type of plastic that can be softened by heat, hardened by cooling, and then softened by heat over and over again.

  • Properties of Thermoplastics: Thermoplastics have wide ranging properties.

  • They can be very much like rubber, or as strong as aluminium. - are light in weight,

  • Can withstand temperature extremes of up to 600 F, while others retain their properties at 100 F. Some

  • Thermoplastic materials have no known solvents at room temperature.

  • Most thermoplastic materials are excellent insulators, both electrical and thermal.

  • Are recyclable materials that are used frequently today to create objects such as foam cups, polyethylene squeeze bottles, acrylic lenses and safety helmets.

  • In general the combination of light weight, high strength, and low processing costs make thermoplastics well suited to many applications.


  • They are useful for a variety of applications, including consumer goods, machine parts, medical equipment and packaging and storage materials.

  • Examples:

    • PVC/Vinyl

    • Polystyrene

    • Polyethylene

    • Cellulose Acetate

    • PTFE/Teflon

    • Nylon/Polyamide

    • Polyester