आकाशवाणी लखनऊ विज्ञान वार्ता सुशील द्विवेदी के साथ विषय विद्यार्थियों ...

बायोटेक्नोलॉजी के चमत्कार

Concepts of Water Footprint

आकाशवाणी इलाहाबाद प्रस्तुती घटती जैव विविधता,संकट मैं जीवन

               Application Biology Notes   

                   By-   Sushil Kumar  Dwivedi PGT Biology 

1. Pests are the organism which may damage the economic and physical well-being of humans e.g. a variety of unwanted, and even harmful insects, weeds (unwanted plant), microorganisms, (fungi, bacteria), rodents, nematodes etc.
2. About 30% of agricultural produce is lost every year due to pests and diseases.
3. Methods for controlling pests:

(a)       Quarantine methods: Inspection and regulation of entry of plant materials

(b)       Mechanical methods: Like trapping of rats, using trenches to stop migration of cockroaches.

(c)       Cultural methods: (i) crop rotation; (ii) uprooting of weeds; (iii) careful selection of healthy, pests-resistant varieties for cultivation; (iv) keeping fields clean by disposing off waste materials.

(d)      Chemical methods: Use of chemicals for the control of pests.

4. Pesticides are those substances which are used to kill, control or repel pests.
5. Depending upon the type of target organisms, the pesticides are classified as fungicides (for fungi), herbicides (for weeds); insecticides (for insects), nematicides (for nematodes), bactericides (for bacteria), rodenticides (for rodents).
6. Chemical pesticides are toxic chemicals used for killing pests.
7. The fungicide, Bordeaux mixture contains 40 g copper sulphate + 40g calcium hydroxide + 5 litres of water.
8. On the basis of chemical composition, chemical pesticides are grouped into:

                         I.      Organochlorines;

                      II.      Organophosphates;

                   III.      Carbamates;

                   IV.      Pyrethoids;

                      V.      Traizines;

                   VI.      Auxin – derivative

            I.          Organochlorines are basically organic compounds which have been chlorinated – chlorinated hydrocarbons (e.g. DDT, BHC, aldrin, endosulfan).

                         i.          DDT i.e. diclorophenyl trichloroethane is the most famous pesticide of the world.

                       ii.          BHC (or HCH) – hexachloro cyclo-hexane – (Benzene hexachloride) is sold under the name Gammexane or Lindane.

Organochlorines (e.g. Aldrin, Endosulfan, BHC, Dieldrin, Chlordane) are lipophilic in nature; hence, slow great affinity for fatty tissues.  They decompose very slowly therefore, get accumulated in environment posing serious problems.

         II.          Organophosphates are organic esters of phosphoric acid, triphosphoric acid and other phosphoric acids.

These are most toxic pesticides to verberates e.g. parathion, malathion, fenetrothion.

Malathion is an ingredient of 'flit'.

Organophosphates act on central nervous system, combining with enzyme acetyl cholinesterase inhibiting its normal functioning and the breakdown of acetylcholine.  It causes acute toxicity resulting in convulsions, paralysis and death.  Their property led to the development of nerve gas used in World War II.

      III.            Carbamates are organic esters of hypothetical carbonic acid e.g. isolan, carbaryl, carbofuran, aldicarb, propoxur.

Methyl isocyanate gas is used as raw material for synthesizing carbaryl.  Carbofuran, Propoxur and Aldicarb are sold as Furadan, Baygon and Temik respectively.

Carbamates act similar to that of organophosphates and have high affinity for the enzyme acetyl cholinesterase.

    IV.              Pyrethroids are synthetic derivatives of pyrethrin-a chemical extracted from an annual plant (Chryssanthemum cinerarifolium).  They do not cause any pollution.

       V.              Triazines are a group of herbicides which are derived from urea e.g. simazines and atrazines.

    VI.              Auxin derivative :- These are 2, 4 – D and 2, 4, 5 – T.  They are herbicides, agent orange is a mixture of 2, 4-D and 2, 4, 5 – T used during Vietnam War.

Pesticides act by affecting lipids and nervous tissues.

Pesticides are useful in

(a) Improving crop yields as these protect crops from pests especially high yielding varieties which are susceptible to pests.

(b) Public health programmes as these kill vectors e.g. mosquitoes, flies etc.

Hazards of overuse of chemical pesticides:-

(a) Environmental pollution: being non-specific, pesticides kill 'non-target' species also.  Also, most of these are non-degrabable and accumulate in the environment.  These also enter the food chain and accumulate in the body of animals through food chain.  This is called biomagnification or bioconcentration.

In India.13-31 ppm of DDT can be detected in the body fat of people (highest in the world).

(b) Toxication of food and other products.

(c) Development of resistance to pesticides: when the pesticides are sprayed, some pest individuals having (i) less permeable utricles, better enzyme equipment of metabolising the toxins, survive and breed the next generations, which are more resistant to pesticides.

Integrated Pest Management (IPM) is the Selection, integration and implementation of pest control based on predicted economic, ecological and sociological consequences.  IPM, seeks to use a variety of biological, physical and chemical methods integrated into a cohesive scheme designed to provide long-term protection.

(a) Biological methods include using nature predators of pests, using varieties, crop rotation, intercropping etc.

(b) Mechanical methods include manual destruction of eggs of pests, removing the weeds.

(c) Use of chemical pesticides is carefully timed.

Domestication and Improvement of Animals

Brief Preview:

Domestication and Improvement of Animals

                       

1.      Animal husbandry is the science of raising, breeding and caring for livestock.

2.      Cattle, buffaloes, sheep, pigs and camel constitute the livestock.

3.      Cattle breeding may be random or through artificial insemination.  Super ovulation and embryo transplantation techniques are used for cattle improvement.

4.      Some of the important breeds of milk producing cows of USA are Holstein – Friesian.

5.      Some breeds of Indian cattle are:

(a)       Milch Breeds: Gir, Sahiwal, Red Sindhi, Deoni.

(b)       Draught Breeds: Malvi, Nageri, Hallikar, Kangayam.

(c)       General Utility Breeds: Haryana, Ongole, Kankrej, Tharparkar.

6.      Some breeds of Indian buffaloes are Murrah, Bhadawari, Jaffrabadi, Surti, Mehsana, Nagpuri or Ellichpuri, Nilli Ravi.

7.      To increase milk yield.  Indian cows have been cross bred with exotic breeds like Holstein, Brown Swiss, Jersey, Red Dane and others.  Indian cattle breeders have developed two varieties of cows by such cross-breeding e.g. Karanswiss and Sunandini.

8.      Important breeds of sheep in India are Lohi, Rampur – Bushair, Nali, Bhakarwal, Deccani, Nellore, Marwari, Patanwadi.

9.      Important breeds of goat in India are Gaddi, Kasmiri Pashmina, Jamunapari, Beetal, Marwari, Berari, Malabari, Bengal.

10.  Sheep are reared for meat and wool and goats for meat, milk and hair.  Selective breeding and cross-breeding have been used for improving the quality of wool and meat yield.

11.  Pigs are reared for pork, ham and bacon which constitute rich animal proteins.  The skin of the pig is used as leather, its bristles for making brushes and fat for soap industry.

12.  Some of the Indian and exotic breeds of pigs are

(a)       Indian Breeds :  Desi, Ghori.

(b)       Exotic Breeds :  Berkshire, Large white Yorkshire, Landrace.

13.  Horses are used for transport, racing and polo.

      The six important breeds of Indian horses are: Kathiawari, Marwari, Bhutia, Manipuri, Spiti, Zanskari.

14.  Donkeys need little care and can withstand adverse weather conditions.  There are two breeds of donkeys in our country: small grey and large white.  The large white is also called wild ass and occurs in Rann of Kutch.

15.  A mule is a hybrid of a male donkey and the mare (female horse).  The hybrid between the female donkey and stallion (male horse) is called a hinny.  Mules are sterile.  Mules show hybrid vigour.  They are larger than the donkey and sturdier than the horse.

16.  The camel is called "The ship of the desert" as it is the most important beast of transport in desert.  There are two kinds of camel.  Arabian, one humped (Camelus dromidarus), Bactrian, two humped (C. bactrianus).

17.  Poultry-farming deals with the rearing of game birds such as domestic fowls, ducks, turkeys and pheasant, which yields eggs and meat, rich in protein and other nutrients.

18.  There are a small number of pure breeds of fowls indigenous to India, such as Aseel, Karaknath, Busra, Ghagus, Brabma and Cochin.  Aseel is one of the best table birds with plenty of flavoured flesh.  The desi birds generally have poor eggs-lying capacity.

      White Leghorn, Rhode Island Red, Plymouth Rock, Barred Plymouth, New Hampshire.  Light, Sussex, Black, Minorcha are some of the exotic breeds utilized for the imported, bred and acclimatized to local conditions.  Some of these varieties are excellent egg-layers while others are good meat-producing birds.

19.  The following are some of the important diseases of the poultry:

Ø  Viral diseases: Fowl fox, Ranikhet (or Newcastle disease).

Ø  Bacterial diseases: Fowl cholera, Salmonellosis, Coryza.

Ø  Parasitic diseases:

(a)         Internal Parasites: Roundworms, tapeworms, threadworms.

(b)         External parasites: Fowlmite, chickenmite, fleas, ticks, lice.

20. Aquaculture is the production of aquatic plants along with animals like prawns, fishes, oyster, etc.

21. Rearing and breeding of fish in ponds, tanks, reservoirs is termed pisciculture. Carp fishes such as Catla (theila).  Labeo ronita (rohu).  Cirrhina mrigala (mrigal) and Labeo calbasu (kalbous) are commonly cultured together in our country.  Such a practice of culture together of fishes is called polyculture or composite culture.

22. Important edible fishes of are:

(a)         Fresh water fishes: Rohu (Labeo rohita), Calbasu (Labeo calbasu), Catla (Catla catla), Singhara (Mystus singhala), Magur (Clarius batrachus), Singhi (Heteropneustes).

(b)         Marine fishes: Bombay duck (Harpodon sp.), Hilsa (Hilsa sp.), Eel (Anguilla sp.), Pomphret (Stromateus sp.), Solmon (Aluitheronema sp.), Sardinella sp.).

23. The practice of rearing honey bees in artificial wooden hives to get honey is called apiculture or bee keeping.

24. Apis, indica, Apis dorsata, Apis flores and Apis mellifera are the popular honey bees.  Apis indica is reared in artificial wooden hives in India because of its docile nature and amiable temperament.

25. The practice of rearing silk worms for the production of silk is called sericulture.  Silk is, in fact, the secretion of silk glands (modified salivary glands) of the caterpillars of an insect (Bombyx mori).  This insect is popularly known as mulberry silk moth.  All the four varieties of natural silk namely, mulberry, eri, tasar and muga are produced in India.

Application Biology Notes by:-   Susheel Dwivedi .

 

Understanding Human Diseases

Brief Preview:

1.    Disease is a condition of the body or of its parts in which normal function are disturbed or damaged causing discomfort or disability.

2.    The disease causing agents are:

(a)         Biological agents or pathogens such as viruses, bacteria, mycoplasma, fungi, protozoans, helminthes and other organisms.

(b)        Nutrient agents such as minerals, carbohydrates, proteins, fats and vitamins.

(c)         Chemical agents such as pollutants, spores, pollen grains, urea and uric acid.

(d)        Physical agents such as heat, cold, humidity, radiation, electricity and sound.

(e)         Mechanical agents such as chronic friction, trauma, sprains, fractures and dislocation.

3.    Robert Koch, identified a set of four conditions to establish relation of specific pathogen with particular disease.  These conditions known as Koch's postulates are:

(a)    The said pathogen should be regularly found in the animals suffering from the disease.

(b)    The pathogen should be isolated and grown in pure culture.

(c)     When this culture is inoculated into a healthy animal, the latter must develop the disease the reveal its characteristic symptoms.

(d)    The same pathogen must be recoverable from the inoculated animal.

4.     Germ Theory: "Certain diseases are caused by the invasion of the body by microorganisms, organisms" was given by French microbiologist Louis Pasteur.

5.     Reservoir of Infection and Transmission of disease:  Every disease producing organism has a 'reservoir of infection' where it normally lives but does not cause disease.  The reservoir may be soil, water, air, animal or other human beings called carriers.

6.     Diseases are transmitted from the reservoir of infection to healthy person in the following ways.

(a)    Direct Transmission:

                                      i.      Contact transmission i.e., through contact between infected and healthy persons.

                                    ii.      Droplet transmission i.e., through sneezing, coughing, spitting and talking.

                                  iii.      Contact with soil which contains saprophytic disease-causing agents.

                                  iv.      By bite of animal.

                                    v.      Transplacental transmission from mother to foetus.

                                  vi.      Through blood transfusion.

(b)     Indirect Transmission:

                                    i.        By vectors, that is transmission by an arthropod or any living organism.

                                  ii.        Vehicle borne, that is transmission through agencies like ice, water, food or other biological products.

                                iii.        Air-borne by wind currents, aerosol sprays and dust.

                                iv.        Fomite-borne, that is through contaminated articles such as crockery, toys, door handles, garments, surgical instruments and syringes.

7.     The body's defense mechanism: 

            The body has two lines of defense against pathogens:

(a)       A non-specific defense mechanism comprising physical and chemical barriers and inflammatory reactions.

(b)       A specific defense mechanism, the immune system.

8.       Non-specific defense mechanisms:

(a)        The skin forms the first line of defense.

(b)        If there is a cut or abrasion on the skin, the body's second line of defense comes into play.  The capillaries and the small blood vessels surrounding the injury dialate and become more permeable.  This produces redness, swelling and heat associated with injury.  Helped by increased blood flow and permeability of the capillaries, phagocytes leak into the interstial spaces and engulf the invading microbes.

(c)         The pus formed at the infected wound is actually the debris of the battle, i.e. a collection of dead cells and body fluids.

(d)        The inflammatory response is due to chemical histamine released from the lymphocytes, and the damaged tissues which cause dilation of the blood capillaries these reactions are generally localized i.e. confined around the wound.

(e)         Many times the fight between microorganisms and W.B.C result in rising of temperature.  This is wide spread and is called systemic reaction.

(f)         The fever is caused by either the toxins released by the pathogens or by the chemicals called pyrogens (the fever producing substance) released by W.B.C that set the body's thermostat at a higher temperature.

(g)        High fiver is not only inhibits the growth of germs but also activates body defenses and is actually beneficial.

9.       The immune system: It has two main components:-

                         A.             Humoral Immune Responses:

                  (a)  The humoral response usually occurs when pathogenic microorganisms get into our bodies.  On entering the lymph nodes they activate b-cells to divide many times by the mitosis and swell to become large plasma cells.

                  (b)  Plasma cells produce large quantities of antibody specific to the antigen which triggered to response.  They enter the blood and circulate as immunoglobulins. They form gamma-globulin fraction of the plasma proteins.

                           B.            Cellular Immune Response:

(a)         The cell-mediated or cellular response is usually brought about by the presence in our bodies of cells with non-self antigens on their surfaces.  Such cells may be part of a transplanted organ.

(b)        Non-self antigens entering the lymph nodes sensitise T-cells, large numbers of these cells are then quickly produced by mitosis, many of them entering the bloodstream.  Such a population of identical cells is called clone.  Several types of T-cell can be recognized in a clone.

(c)         Killer T-cells attach to the invading cells into which secrete a number of cellulotoxic substances.  The substance may be enzymes from the killer cells lysosomes.  Other substances secreted by T-cells are called lymphokines such as interferon.  It prevents viral replication.

(d)        Helper T-cells help the plasma cells produced by b-lymphocytes to secrete antibodies.

(e)         Suppressor T-cell suppress the activity of killer T-cells and b-cells.  Interaction between suppressor T-cells and Helper T-cells regulates the immune response.

(f)         Memory T-cells retain in the ability to recognize the non-self antigen in the future.

(g)        Immunity: Immunity is the ability of an organism to resist and/or overcome harmful infection or agents.  There are tow principal types of immunity in animals:

Ø  Active immunity: Contact of an individual with pathogenic organisms or their product stimulates the body to produce antibodies (gamma globulin proteins) in response to the antigen.  It is specific for a particular disease.  It may be active natural immunity or active induced immunity.

Ø  Passive immunity:  By transfer of antibodies formed in one human being to another.

(h)        Autoimmunity

Ø  Sometimes, the immune system fails to judge between 'self' and 'non-self' and turns against 'self'.  This disorder is called autommunity.

Ø  If self-antigen is R.B.C. (Red Blood Corpuscle), there occurs excessive destruction of body's own RBCs resulting in chronic anaemia.  If self-antigen is muscle cells, it results in destruction of body's own muscle cells.  It leads to severe muscle weakness.  This autoimmune disorder is called myasthenia gravis.  If liver cells are autoantigens, it leads to chronic hepatitis.

(i)          Immune Disorder:

                       

                         Immunodeficiency:  Sometimes, new borns are without b-cells and T-cells hence highly prone to infections.  E.g. servere combined immunodeficiency (SCID).  Such babaies are highly susceptible even to minor infections.

(j)        Acquired Immuno Deficiency Syndrome (AIDS):

Ø  AIDS is a disorder of cell-mediated immune system of the body characterized by a reduction in the number of helper T-cells which stimulate antibody production by B-cells resulting into loss of natural defense against viral infection.

Ø  AIDS first recognized in the year 1981 in U.S.A is caused by HIV (Human Immuno Deficiency Virus).

Ø  AIDS is transmitted by (i) intimate sexual contact, (ii) use of contaminated needless and syringes, (iii) blood transfusion, (iv) organ transplant, (v) artificial insemination.  Hoosexuals drug users, recipitients of transfused blood and blood products, heterosexual sex partners of AIDS patients are more prone to AIDS infection.

(k)        AIDS – related complex (ARC):  a set of symptoms, such as symph node enlargement, fever, loss of weight, diarrhea, and minor opportunistic diseases associated with a weakened immuse system, which indicates a less severs form of infection by HIV.

Application Biology Notes by:-   :-   Sushil Kumar  Dwivedi PGT Biology K V Aliganj Lucknow .

 

Common Human Diseases

Brief Preview:

1.      Common Human Diseases: Communicable diseases are caused by some germs passed from one person to another.

(a)        Diseases caused by bacteria

             i.  Tuberculosis is caused by Mycobacterium tuberculosis.  It affects the lungs, lymph nodes, bones and joints.

           ii.  Diphtheria is caused by Corynebacterium diphtheriae.

Oozing of semisolid causing of the air passage.

The diphtheria antitoxin, if given within 24 hours of appearance of symptoms.

         iii.  Whooping Couth (pertussis) is caused by Bacillus pertussis.

Prevention and Control: Immunisation using DPT vaccine.

       iv.    Cholera is caused by Vibrio cholerae.

         v.    Thphoid is caused by Salmonella typhi.

       vi.    Syphillis is caused by Treponema pallidum.

  Gonorrhoea is caused by Gonococcus, Neisseria gonorrhoeae.

(b)     Diseases caused by viruses:

          i.      Measles (Rubeola) is caused by myxovirus.

        ii.      Chicken Pox is caused by Varicella-zoster virus.

      iii.      Poliomyelitis is caused by enterovirus (polio virus).

   The first polio vaccine was prepared by Jonas Salk (1953).  Albert Sabin prepared a polio vaccine that can be administered orally rather than by injection.  Viruses are also responsible for many other diseases including influenza, small pox, viral hepatitis, rabies and mumps. In pulse polio programme oral polio vaccine (OPV) is used for vaccination of children. 

(c)       Diseases caused by protozoa:

          i.      Malaria is caused by malarial parasite Plasmodium.

        ii.      Amoeba Dysentery is caused by Entamoeba histolytica.

(d)   Diseases caused by helminthes:

          i.      Taeniasis is caused by the tapeworm.  Taenia soluim.

        ii.      Ascariasis is caused by roundworm, Ascaris lumbricoides.

      iii.      Filaria is caused by a thread like filarial work, Wuchereria bancrofti.

2.Non-communicable diseases:

       Non-communicable diseases are confined to the persons who are suffering from them and are not passed from person to person.

        i.        Diabetes mellitus is due to the deficiency of insulin.

      ii.        Cardiovascular diseases:

(a)       Rheumatic heat diseases result from repeated attacks of rheumatic fever in childhood.  Which is caused by streptococcal infection of the throat.

(b)      Hypertensive heart diseases are caused by increased blood pressure.

(c)       Coronary heat diseases are characterized by insufficient supply of blood to the heart muscle which results in heart attack.

         This is due to thickening and hardening of the walls of coronary arteries by deposits of fatty materials (arteriosclerosis).

         Sometimes coronary arteries may rupture or clot may be formed in them.  It is called an infarction.

    iii.          Aching joints

(a)         Arthritis is caused by inflammation of joints.  It is a degenerative disease which occurs with age.  There are two kinds of arthritis – rheumatoid arthritis and osteoarthritis.

                         i.        Rheumatoid arthritis:  It is due to the inflammation of the synovial membrane.

                       ii.        Osteoarthritis: The joint cartilages degenerate and their articular surfaces become rough.

(b)        Gout results from the deposition, in and about the joints, of salt of uric acid.  This is characterized by recurrent acute attacks of severe inflammation in one or more of joints of extremities.

    iv.          Cancer is characterized by the uncontrolled multiplication of abnormal cells in the body.  The spread of cancerous cells to distant sites is termed metastasis.  It may be broadly classified into three major categories:

(a)       Carcinomas are malignant growths of the epithelial (ectodermal) tissue that cover on line the body organs, e.g. skin cancer, breast cancer, lung cancer, cancer of the stomach and pancreas.

(b)      Sarcomas are malignant growths arising in tissues derived from primitive mesoderm, e.g. bone tumors, muscle tumors, cancer of lymph nodes.

(c)       Leukaemias results from unchecked proliferation of cell types present in blood and their precursors in the bone marrow.

3.Human genetic disorders:

        (a)   Disorders due to incompatibility of blood groups.

               (a)  Rh factor incompatibility.  Rh factor is a protein on the surface of red blood corpuscles in many persons discovered by landsteiner and Wiener in the blood of Rhesus monkey.  Majority of the people (95% to 99%) have this factor and are classified as Rh-positive (Rh+).  Others (1 % to 5%), who lack this factor, are called Rh-negative (Rh–).

                       If Rh negative pregnant women carry a Rh positive baby in her womb, anti-Rh agglutinins develop in the blood of mother during first pregnancy, enough anti Rh agglutinins will not be produced during a first pregnancy and the baby will be safe.  At the time of second pregnancy if the child is again Rh-positive, the anti-Rh agglutinins from them other blood will attack the RBC's of the embryo and death of the fetus may occur.  This is known as erythroblastosis foetalis.

               (b)   ABO Incompatibility.  Blood group incompatibility between mother's and child's (foetal) blood may cause complications.  An O type mother having anti-A and anti-B antibodies in her blood may carry an a-type foetus.  Anti-a antibodies reaching foetal circulation may destroy foetal red cells as they carry the a-antigen.  The child may be delivered with anaemia and juadice.

                        This Blood disorder is known as haemolytic diseases of the new-born.

           (b)    Recessively inherited disorders:

                        Some autosomal recessively determined disorders in humans are albinism, phenylketonuria and infantiale amaurotic idiocy (Tay-sach's disease)

                   (a)  Albinism:  The inherited absence of pigmentation in the skin, hair and eyes.

                   (b)  Phenylketonuria is an inborn defect of protein metabolism causing an excess of amino acid phenylalanine in the blood, which damages the nervous system and leads to revere mental retardation.

                   (c)   Tay-sach's  disease  or  infantile  amaurotic  idiocy  is  a  hereditary  metabolic disorder that causes progressive mental and neurologic deterioration and results in death in early childhood.  The disease in inherited as an autosomal recessive trait.

           (c)    Dominantly inherites disorders:

                        The people exhibiting the dominantly inherited disorders always have one of the portents carrying  the gene. E.g. Polydactyl, Hutington's chorea, defective enamel of teeth.

                   (i)   Polydactyly is characterized by the presence of more than the normal number of fingers or toes.

                   (ii)  Hutington's chorea is a neurological disorder characterized by irregular and purposeless movement of muscle groups in various parts of the body.

                   (iii)  Defective enamel of teeth gene is located on X-chromosome.  It is found more frequently in women than in men.

           (d)    Disorder arising from chromosomal abnormalities: Autusonal abnormalities

                   (i)    Down's syndrome due to trisomy 21 or mongolism.  It prominent forehead, flattened nasal bridge, habitually open mouth, projecting lower lips, a large protruding tongue; characteristic skin fold at the corner of the eye; malformed heat gonads and genitals underdeveloped mental retardation.

                   (ii)  Patau's syndrome results from an extra (third) copy of chromosome 13 characterized by mental retardation and severe development malformations like small head, a cleft plate and lip, tiny eyes, polydactyly, central nervous system abnormalities, and defects in many internal organs.

                    (iii)   Edward's syndrome is caused by an extra 18^th chromosome and is characterized  by defective nervous system, malformed ears and receding thin.

           (e)    Sex chromosome abnormalities:

                   (i)   Klinefelter's syndrome is caused by the presence of an extra X-chromosome in males, charaterised by the external genitalla male type but the testes are consistently very small: female like breast development (gynecomastia) and his body has sparse hair; usually long legged; mentally retarded.

                   (ii)  Turner's syndrome (monosomy of X-chromosome or XO).  An XO individual, usually formed by and X-carrying sperm fertilizing an egg without X-chromosome (O).  Affected individual show symptoms like female-like external genitalia; short stature and subnormal intelligence; ovaria dysgenesis, i.e. the ovaries are absent or are present only as primitive streak, webbed neck; broad shield-like chest with widely spaced nipples and small uterus.

                   (iii)  Super females: Such individuals have 47 (44 XXX), 48 (44 XXXX) or 49
(44 XXXXX) chromosomes characterized by abnormal sexual development and mental retardation.

                   (iv)   XYY – trisomy: An XYY male is usually taller, often and often has reduced intelligence.  It presence of an extra Y chromosome in an individual may cause him to be more aggressive and prone to criminal behaviour.

Technology for Medical Application

Brief Preview:

      1.    Diagnostic Instruments:

            (i)    Electrocardiograph:  A electrocardiograph senses the electrical forces that are produced due to contraction and relaxation of heart muscles during a cardiac cycle.  A graphic record of spread of the cardiac impulse through the heart is called electrocardiogram (ECG).  ECG is used to know rhythm of heart beat and know the conditions of heart muscles.

            (ii)   William Einthoven (1986 – 1927), Dutch physiologist who was awarded the 1924 Nobel Prize for physiology or medicine for his discovery of the electrical properties of the heart through the electrocardiograph.

            (iii)  SQUID (Super Conducting Quantum Interference Device) is used to study weaker magnetic fields of the brain.  This new technique called magnetoencepholography (MET) assures an important investigation tool in the study of brain health and disease.   

            (iv)  Autoanalyser : This is computer-controlled apparatus used to estimate various biochemical substances e.g., glucose, urea, cholesterol, enzymes and other proteins present in the fluids.

      2.    Imaging Instruments

            (i)    Computed Tomographic Scanning (CT):  Imaging technique is based on the application of X-rays. Computed tomography (CT) technique was invented by Sir Godfrey Hounsfield, who was awarded the Noble Prize in 1979.

                   Computer tomographic scanning (CT) also uses X-rays but employs computer for reconstructing the image instead of directly recording it on photographic film.

           (ii)   Positron Emission Tomographic Scanning (PET) is also a computerized imaging technique and gives a quantitative information for various physiological processes in the body.

                   PET – imaging is used in the measurement of regional cerebral blood volume, blood flow, metabolic rates for glucose and oxygen in humans.

            (iii)  Nuclear Magnetic Resonance Imaging (NMR)

                    NMR was discovered by Purcell and Bloch (1952) and on the principle that magnetic resonance generated by nuclei of hydrogen atoms is subjected to an external magnetic field.  Thus, NMR signals are produced these signals are fed to computer for image construction as in CT or PET scanning.

            (iv)  Ultrasound Imaging or Sonography:  The word ultrasound refers to the sound beyond the range of human hearing.  The waves of ultrasound are produced by piezoelectric effect based on the principle that when an electric potential is applied to certain crystals like lead zirconate, they become excited and start vibrating and produce ultrasound.  When these sound waves through a homogenous tissue they remain unimpeded till they meet another tissue or organ.  From these, a part or the whole of ultrasonic wave is reflected back by the some crystal and is converted into an electrical signal which can be seen on an oscilloscope screen.

      3.    Therapentic Instruments:

            (i)    Pacemakers:  It is an artificial device to keep the pace of the heat.  It generates heat beat somewhat at a normal rate.  It was first implanted by Chardack (1960).  Rate of a patient falls to about 30-40 per minute due to any reason.

            (ii)   Medical Lasers:  Laser are high energy particles of light amplified by stimulated emission of radiation.

            (iii)  Lasers can be specifically targeted as powerful energy beams to any type of tissue hence used in different kinds of surgical operations e.g. brain tumors, retinal tumours as well as tumours of other part of the human body.  A high energy beam is concentrated on the localized cancer cells.  The treatment selectively "burns" the cancer cells without affecting the normal cells.

            (iv)  Intra-aortic balloon:  Sometimes body organs fail temporarily due to diseases and need support.  Intra-aortic balloon pump is used to support the ventricle by increasing the blood supply to the heart muscle.  Intra-aortic balloon pump consists of a special balloon positioned in the descending thoracic aorta.  It is connected through a tube to an external machine which inflates and deflates the balloon rhythmically with helium.  During diastole more blood is pushed into the coronary arteries which nourishes the heat muscle.  During systole when the balloon  deflates (the contractile phase of the heart), the impedance for the pumping action is reduced.

      4.    Implants:

            (i)    Artificial Heart Valve:  Artificial mechanical valves are made up of special plastics, metal alloys or ceramics.  The tissue valves are usually taken from cadavers or pigs or fashioned from the pericardium of animals.

            (ii)   Vascular Grafts (artificial arteries):  In both the occlusion and aneurysm, the defective segments of arteries are either replaced or an alternative root is fabricated by using artificial arteries or vascular grafts.  These are made of porous plastic fibre of Dacron and Teflon.  These arteries remain open for many years and function well.

      5.    Disposables:

            (i)    Oxygenator : It is used in the oxygenation of blood during open heart operations.  The technique "heart lung bypass" was used in 1953, in first open heart surgery.  In this technique, the heart and lungs of the patient are bypassed and their vital functions are carried out by heart-lung machine.  The function of the heart is carried out by a roller pump and oxygenation of blood it done by oxygenator.

            (ii)   Blood Bag: Blood bags are used to avoid blood infections and for separating blood components such as red blood cells, white blood cells, platelets etc by centrifugation.

            (iii)  Blood dialyser (artificial kidney) is a device to filter the blood of patients whose kidneys are completely damaged.

     6.     External Prosthesis:  Prosthesis is an artificial substitute for any part of the body leg and arm prosthesis are most common life.  Dr. P.K. Sethi of Jaipur had been successful in the evolution of "Jaipur foot".  This foot resembles the natural foot: it is light and allows desirable range of movement in all directions.

Biotechnology

Brief Preview:

      1.    Biotechnology is the utilization of living organisms (or of substances obtained from them) in industrial processes.

      2.    The organisms involved in biotechnology range from complex organisms like cattle to simple unicellular yeast.

      3.    Louis Pasteur showed that beer and buttermilk are products of fermentation carried out by Saecharomyces cerevisiae (yeast).

      4.    Yeasts are used for baking, brewing alcoholic beverages, and manufacturing fermented food.

      5.    Yeasts are of two types: (a) baker's yeast (used as a leavening agent and to flavour food products), (b) alcohol yeast.

      6.    Fermentation may be carried out in two ways: (a) Batch process (entire culture medium with organism is removed from the bioreactor after every batch,
(b) Continuous process (a fraction of the medium with fermented product is drawn out at regular intervals and fresh medium is introduced into the bioreactor, i.e. fermentation tank).

      7.    Fermentation using yeasts is carried out in three steps:

            (a)    Sterillisation (of fermentor and nutrient medium in steam under pressure).

            (b)   Inoculation (of selected strain of yeast).

            (c)    Recovery of product.

      8.    (a) From fermentation medium:  Ethanol, n-propanol, butanol amyl alcohol, phenylethanol, glycerol, acetic acid, lactic acid, pyruvic acid, succinic acid, caprylic acid, ethyl acetate and other ester of acid and alcohol fermentation products, carbon dioxide, acetaldehyde, diacetyl and hydrogen sulphide.

            (b)   Yeast extract, food supplements and vitamins from yeasts.

      9.    Microorganisms may be grown in the bioreactor:

            (a)    As a layer or film on the surface of nutrient medium (support growth system), or

            (b)   By suspending them in liquid medium in smooth vessels (suspended growth system).

      10.  Lactic acid bacteria are very important for dairy industry.  Pure cultures are added as "Starter cultures" to milk.

      11.  A sour cream butter is prepared from cream by Lactobacillus lactis, L. cremoris and Leuconostoc cremoris.

      12.  Lactococcus lactis or Lactobacillus bulgaricus and Strepotococcus thermophilus are used for the coagulation of casein in the production of soft cheese (e.g. curd, cheeses) and for 'hard cheese' rennin is used.  Lactobacillus casei, Lactococcus lactis and Propiniobateria are used for maturation.

      13.  Yoghurt: is prepared by Sheptococcus thermophilus & Lactobacillus bulgaricus.

      14.  Earlier, cheese was prepared using sap fig trees containing enzyme ficin.  Christian Hansen (1874), purified 'Renner' enzyme for large scale industrial use.

      15.  The enzyme diastase was identified by Payne and Persoz (1993).

      16.  (a)    Proteases are used in the detergents to remove proteinaceous stains. 

            (b)   Amylases are used in manufacturing beer, bread and textiles.

            (c)    Amylases, glucoamylases and glucoisomerases transform corn starch into high fructose syrup.

            (d) Lactases break down lactose into glucose and galactose.

      17.  The enzyme TPA (Tissue Plasminogen Activator) is used to dissolve blood clots particularly in case of heart attacks.

      18.  An enzyme can be immobilized by (a) covalently attaching the enzyme to a solid support, (b) entrapping it in a gel, (c) cross linking the enzyme molecules to one another, (d) encapsulating them in small artificial cells.

      19.  Babes (1855) demonstrated that microorganisms produce substances which inhibit growth of other organisms.

      20.  Louis Pasteur and Joubert (1877) showed that certain bacteria inhibited the growth of Bacillus anthracic.

      21.  Paul Vuillemin (1889) proposed the concept of antibiosis.

      22.  S. A. Waksman (1942) coined the term 'antibiotic'.

      23.  Waksman and Woodruff isolated actinomycin (in 1941) and streptomycin (in 1942).

      24.  The actinomycete – Streptomyces yields antibiotics chloramphenicol, erythromycin, leucomyein neomycin, novobiocin, oxytetracycline, spiramycin.

      25.  Board spectrum antibiotics are those which are able to act on several pathogenic species.

      26.  Three groups of microorganisms which are source of most of the antibiotics today are (a) Eubacteriales, (b) Actinomycetales, (c) Fungi, Penicillin and Cephalosporin are manufactured from Penicillium chrysogenum and Cephalosporium respectively.

      27.  Actinomycetes, like Streptomyces, Nocardia, Micromonospora, Streptoverticillium are main sources of antibiotics.

      28.  Monoclonal antibodies: are produced by fusing normal antibody-producing cells with myclomas (cells from cancerous tumours).  The resulting hybrid cells, called hybridomas, produce only one kind of antibody on a large scale.  This idea was conceived by Georges Kohler and Cesar Milstein (1974).

      29.  Monoclonal antibodies are useful for diagnosis of diseases caused by closely related pathogens immune suppression for kidney transplantation.

      30.  Second generation vaccines: are those produced by genetic engineering (e.g.  vaccines for Hepatitis B and Herpes virus).

      31.  Synthetic vaccines are third-generation vaccines.

      32.  Vitamin C was the first vitamin to be produced during fermentation process using a wild bacterium.

      33.  Vitamin B₂(cobalamine) was isolated from liver extract and now, is produced directly through fermentation of propiniobacteria and some strains of pseudomonas.

      34.  Vitamin B₂ (Riboflavin) is obtained on large scale from the fungus Ashbya gossypi.

      35.  Lactic acid was the first acid to be produced by fermentation.

      36.  Citric acid is produced industrially from yeast by subjecting to it shortage of minerals like iron and manganese. Citric acid is commercially obtained from aspergillus niger.

      37.  Oestrogens and progesterones are most widely used steroids for birth control pills.

      38.  Murray and Peterson: (1950) demonstrated the Rhizopus stolonifer causes hydroxylation required for steroid synthesis.

      39.  Appropriate recombinant E.coli clones carrying genes for human insulin prepared by genetic engineering, can be used in factories for synthesis of specific hormone.

      40.  An American firm Elli Lilly launched first genetically engineered human insulin (humulin).

      41.  Weismand obtained interferon through recombinant E.coli in 1980.

Bioenergy

Brief Review:

      1.    Bioenergy is the energy obtained from biological sources (animal energy and biofuels).

      2.    Animal energy is available in two forms (i) Human Muscle Power (HMP), (ii) Draught Animal Power (DAP).

      3.    HMP (e.g. women in domestic work, labourers) is equivalent to approximately 20% of total electricity generation.

      4.    Drought animals are used in agriculture and for transport.

            Their efficiency can be improved by (i) improvement of carts, (ii) providing them nutritious fodder, (iii) breeding improved animals.

      5.    Biomass includes living organisms and their residues.  These include (a) terrestrial biomass (organic residues like wheat and paddy straw, poultry manure, tree bark, saw dust, organisms and their dead bodies), (b) aquatic biomass (marine and fresh-water animals/plants/other organisms).

      6.    Biofuels (fuels of biological origin) are in use since the discovery of fire and are renewable.

      7.    Biomass can be used (i) to generate producer gas to run irrigation pumps, (ii) to obtain alcohol (iii) to replace petrol, (iv) to generate biogas for cooking and lighting, (v) to produce electricity.

      8.    A major quantity of wood is used as firewood.  Good fire wood must be highly combustile, must have high calorific value, must be easy to dry, must not be split when ignited must be non-resinous and non-smoky.

      9.    Fuel wood crisis.  At least two billion people depend upon wood for fuel.  In some cases, collection of fuelwood consumes 100-300 days of work for an average family.

      10.  The first step to meet fuelwood crisis is to grow more fuelwood trees (energy plantations).

      11.  The advantages of energy plantations are:

            (i)  Storage of solar continuously: (i) Renewability, (iii) Economical, (iv) Ecological safety.

            (ii)   Availability of sufficient manpower to raise them.

      12.  Trees yielding good firewood include:

            (a) Acacia nilotica (babul), (b) A. senegal (gum Arabic), (c) Adina cordifolia (haldu), (d) Albizzia sp. (siris), (e) Anogeissus latifolia (dhawa), (f) Azadirachta indica (neem), (g) Casuariana equisetifolia (jangli jhan), (h) Ceripos togal (goran nagkesar), (k) Heritiera minor (sundry), (l) Hopea sp. (dammar tree), (m) Lagerstroemia sp. (jarul), (n) Mesua ferrea (nagkesar), (o) Quercus sp. (oak), (p) Prosopis cineraria (Khejri), (q) Syzygium cumini (jamun).

      13.  Some widely distributed species unfit for fuel include Bauhinia racemosa (kachnar), Bombax ceiba (semul), Mangifera indica (mango), Madhuca indica (mahua), Michelia excelsa (champak), Pinus roxburghii (chir).

      14.  Social forestry and energy plantations on non-agricultural land can provide and alternate sources of firewood.

      15.  Social forestry means raising of forests by communities of people for obtaining fodder, minor timber etc.

      16.  Species for energy plantation must be (i) local, (ii) fast growing, (iii) having high coppicing ability, (iv) hardy, (v) requiring low inputs of water and fertilizer, (vi) impose minimum drain on nutrients, (vii) having low transpiration losses, (viii) resistance to pests and diseases, (ix) having wood with high calorific value.

      17.  Energy from wood must be obtained more efficiently through process like carbonization, pyrolysis and gasification.

      18.  Waste biomass, produced by argicultural, industrial and household activities.

      19.  Burning of 50kg of fresh cow dung in the form of dung cake (30,000 kcal of energy) yields 3000 kcal of energy accompanied by air pollution.

      20.  Through biogas production, 2700 kcal of useful energy can be produced from 50 kg of fresh cow dung.  There would be no pollution plus we get fertiliser for one acre of land for two crops per year.

      21.  Biogas (composed of 50-70% methane, 30-40% CO₂, and traces of hydrogen, nitrogen and H₂S) is produced by anaerobic fermentation of biomass.  Its calorific value is about 23-28 KN/m³.

      22.  Biogas production involves three steps:- (i) facultative anaerobic breakdown the polymers into soluble monomers through enzymatic hydrolysis, (b) conversion of monomers into organic acids, (iii) generation of methane.

      23.  Potential substrates for biogas generation include animal wastes, crop residues, human wastes, forest residues, aquatic plants (e.g. Eichhornia), urban solid wastes.

      24.  Melvin Calvin found that certain plants of family Euphorbiacae convert a substantial amount of photosynthetic into latex-containing hydrocarbons, which are potential substitutes for petroleum.

      25.  Asclepiadacease, Apocyanaceae, Leguminosaes, Sapotaceae, Moraceae.  Dipterocarpaceae and Compositae families also have plants which can yield petroleum substitutes.

            Alcohol fuel (Energy Cropping)

      26.  Ethanol can be partly or wholly substituted for petrol in automobiles after suitable modifications in engines.

      27.  Raising of crop like sugarbeet, tapioca, potato, sugarcane for producing ethanol is called energy cropping.

      28.  Alcohol has been successfully used as motor fuel in Brazil.

      29.  Plants producing hydrocarbon (Petroleum Plants):

            (i)    Hevea brasiliensis (Hevea Rubber), (ii) Euphorbia abyssinica, E. resinifera, E. lathyris (rubber plant), (iii) e. tirucalli (sehund), (iv) Partherium argentatum (guayule), (v) Taraxactum koksaghyz (Russian dandelion), (vi) Calotropic procera (aak, milkweed), (vii) Capaifera langsdorfii, (viii) C. multijuga, (ix) Hardwickia pinanata, (x) Dipterocarpus turbinatus (gurjun), (xi) Dialynthera otoba, (xii) Pittosporum resiniferus.

Application Biology Notes by:-   Susheel Dwivedi .

 

Growth of Human Population

Brief Preview:

      1.    Demography – Statistical study of human population is known as Demography.

      2.    Biotic potential – Reproductive potential or physiological capacity of reproduction.

      3.    Population density – Number of individuals per square unit area.

      4.    Natality rate – Number of individuals born per (Birth rate) thousand as per year. [In India -36 or 36%]

      5.    Mortality rate – Number of individuals died per (Death rate) thousand per year.  [In India – 15%]

      6.    Zero population growth – When birth rate / or number of individuals added in a population equal number of individuals lost.

      7.    Sigmoid curve:  Population increases when the birth rate is more as compared to rate of mortality. But due to the sizeable number individuals die and population growth declines until zero population growth is reached curve of growth rate assumes 'S' shape.  This is called sigmoid curve.

      8.    Carrying capacity – The maximum number of individuals which the environment can sustain or support.

      9.    Environment resistance – Factors which impose a check on population growth (Predators, food shortage).

      10.  Most populous country – China, India is number two.

      11.  Causes of over population:-

            (i)    Control on natural calamities – Flood, cyclones.

            (ii)   Control over diseases and epidemics

            (iii)  Agriculture production.

            (iv)  Transportation.

            (v)   Decreased infant mortality rate.

            (vi)  Community health survives.

      12.  Control of population can be done by:-

            (i)    By education – People must be educated.

            (ii)   By fixing marriage age – M21/F18 years.

            (iii)  By birth control methods like

            (a)    Ovulation Check – oral contraceptive pills prevent ovulation (Estrogen + Progesterone).

                    *  Morning pills (Prevent implantation).

            (b)   Fertilization – Tubectomy in female, Vasectomy in male.

                    *  IUCD ®  (Intra Uterine Contraceptive Devices) as copper T, Loops, Diapphragm.

                    *  Condoms ® in males.

                    *  M.T.P. ® Medical Termination of Pregnancy (Abortion).

      13.  Test Tube Babies – In cases where a woman is unable to have a normal conception, ova of such a woman is removed, fertilized by the sperm of her husband and the fertilized egg or ovum is maintained in vitro until 32 celled stage and is then implanted in her uterus.  Under expert medical care a normal baby can be produced by such a mother.  This baby is called a test tube baby.

      14.  First test tube baby – Louise Joy Brown born on July 25, 1978 in England – Dr. Patrick Steptoe and Dr. Robert Edward are credited for this.

      15.  "World population day – 11^th July" and world environment day 5^th June.