Application Biology Notes
By- Sushil Kumar Dwivedi PGT Biology
- 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.
- About 30% of agricultural produce is lost every year due to pests and diseases.
- 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.
- Pesticides are those substances which are used to kill, control or repel pests.
- 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).
- Chemical pesticides are toxic chemicals used for killing pests.
- The fungicide, Bordeaux mixture contains 40 g copper sulphate + 40g calcium hydroxide + 5 litres of water.
- 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
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
White Leghorn ,
Rhode Island Red, Plymouth Rock, Barred Plymouth , New
Hampshire Sussex
19. The
following are some of the important diseases of the poultry:
Ø
Viral
diseases: Fowl fox, Ranikhet (or Newcastle
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
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
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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.
|
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 18th 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.
(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).
(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.
|
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
5. Mortality
rate – Number of individuals died per (Death rate) thousand per year. [In India
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
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
15. "World
population day – 11th July" and world environment day 5th
June.
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