Navodaya Vidyalaya Samiti – Bhopal Region.
UNIT – VIII
HUMAN HEALTH AND DISEASES
What is Health: According to WHO(1948):-Health is a state of complete physical, mental and social well
being and not merely an absence of disease or
physical fitness.
 Health is affected by:1. Genetic disorders:-defeciencies occurs by birth in child and this is inherited from their
parent.
2. infections:3. life style:-including food and water we take,rest and exercise we give to our
bodies,habits that we have or lack.
 Disease:-Any condition which interferes with the normal functioning of the body and impairs
the health is called disease.
 Symptoms:-When a person suffers from disease the functioning of one or more organs of the
body will change for the worse,these changes give rise to certain signs is called symptoms.
 Classification of disease:1. Communicable Disease
2. Non-communicable Disease
3. Congenital Disease(Genetic disorders)
 Communicable disease:=>Easily transmitted to one person to another person.
=>Caused by pathogens,like viruses,bacteria,fungi,flat worms ,round
worms etc.
=>Infectious disease are very common.
=>some infectious disease like AIDS are fatal.
=>Example of communicable Disease:- Tphoid,pneumonia,tuberculosis
,cholera,hepatitis,polio,rabies,common cold,anthrax,leprosy etc.


Non communicable Disease:=>These disease remain confined to the person who develops them and do not spread to
others.
=>Example:-Cancer,asthema,gastric ulcer,arthritis,goiter,diabetes etc.
Congenital Disease:-These disease inherited from parent to child like-sickle cell
anemia,haemophili etc.

Common Disease in human:-




(1) TYPHOID:Typhoid is a bacterial disease.
Causative organism-Salmonella typhi.
Disease is common in children age group 1 to 15 year.
It is fifth most common communicable disease in India.
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It attacks about 2.5 million Indian every year.
Transmission:-By contaminated food and water.
Incubation period:- 1-3 weeks(average 2 weeks)
Symptoms: Sustained high fever(39 to 40 ).
 Weakness
 Stomach pain
 Constipation
 Headache
 Loss of appetite
 The temperature goes on rise during the first week and then gradually comes down
 Liver and spleen become enlarged
 Intestinal perforation and death may occur in severe cases
Confirmation: widal test.
Prevention and control: Proper sanitation of human faces.
 Screening of water and food sources.
 TAB-vaccine provides immunity for about 3 years.
 Typhoid oral vaccine.
A classic case in medicine,that of mary mellon nick named
Typoid Mary she was a cook by
profession and was a typhoid carrier who continued to spread typhoid fo several years through
the food she prepaired.
(2) Pneumonia:Causative organism:a.Streptococcus pneumoniae
b.Haemophilus influenza
Transmission:A healthy person acquires the infection by inhaling the
Droplets/aerosols released by an infected person and
Sharing glasses and utensils with an infected person.
Incubation period:- 1-3 days
Symptoms: Fever
 Chills
 Cough and headache
 Pain while breathing
 In severe case the lips and finger nails may turn grey to bluish in color.
Prevention and control: Isolation of the infected person
 The disease can be treated with antibiotic drugs.
Some other bacterial disease-dysentary,plague,diphtheria etc.
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(3)Common Cold: It is caused by rhinoviruses.
 These viruses infects the nasal and respiratory passage.
Transmission: It spreads by cough and sneezing droplets from an infected person to healthy person and
contaminated objects.
Symptoms: Nasal congestion and discharge.
 Sore throat
 Cough
 Headache
 Tiredness
 Hoarseness
 It lasts for 3-7 days
(4)MALARIA: It is a protozoan disease.
 It is caused by different species by plasmodium like-Plasmodium vivax ,Plasmodium
falciparum ,Plasmodeum malariae.
Transmission:-The infection is through the bite of female Anopheles mosquito that transfers
the sporozoits of plasmodium.
Life cycle of pathogen: The sporozoites enter the body reach the liver through blood and multiply within the liver cell.
 Such liver cells burst and release the parasite into blood.
 Then they attack RBCs,multiply and cause their rupture.
 The rupture of RBCs associatedwith the release of a toxin called haemozoin which I
responsible for the high recurring fever and chill/shivering.
 Sexual stages (gametophyte) develop in the red blood cells.
 The parasite then enters the female Anopheles mosquito along with the blood when it bites the
infected person.
 Further development occurs in the stomach wall of mosquito.
 The gametes fuse to form a zygote.
 The zygote undergoes further development in the body of the mosquito to form sporozoits.
 Sporozoits are transported to and stored in the salivary gland of mosquitoes and are transferred
to a human body during the bite of the mosquito.
Prevention:-The disease can be controlled by eradicating the mosquitoes and avoiding mosquito
bite by using mosquito repellents,mosquito nets etc.
Treatment:-By using of chloroquines.
(5)AMOEBIASIS: It is a protozoan disease.
 It is caused by entamoeba histolica.
 Infection is through contaminated food and water.
 The pathogen resides in the large intestine.
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Transmission:-Houseflies act as mechanical carriers and transfer the parasite from the faeces of
infected person to the food articles and water.
Symptoms : Abdominal pain and cramps.
 Stool with excess mucus and blood clots.
 Constipation with altering diarrhoea.
(7)RINGWORM: It is a fungal disease.
 Caused by fungi like-Microsporum,Epidermophyton,Trichophyton.
 Ringworms are generally acquired from soil or by direct contact with the contaminated
articles used by the infected persons.
 Symptoms include:-Dry scaly lesson on skin,nails and scalp,lesions are accompanied by
itching.
(8)ASCARIASIS: It is caused by Ascaris lumbricoides.
 Infection is through contaminated vegetables,fruits and water as egg of parasite excreted by
the infected persons contaminate soil plants and water.
Symptoms: Blockage of intestinal passage
 Anemia
 Abdominal/muscular pain
 Internal bleeding
 Nausea and headache
(9)FILARIASIS/ELEPHANTESIS: It is caused by Wuchereria bancrofti and Wuchereria malayi.
 They normally cause inflammation of the organ in which they live for many years.
 They normally affect the lymph vessels of the lower limbs(causing them to swell like that of
an elephant,hence calledelephantiasis).
 Genital organ may also be affected leading to gross deformation.
 Female culex mosquito is the vector.
IMMUNITY:The ability of the host to fight the disease causing organism is called immunity.
 Classification of immunity:1. Innate Immunity
2. Acquired Immunity:-two types
 Active immunity
 Passive immunity
(1)INNATE IMMUNITY:=>All the defence element present in an individual by birth and is always available to protect the
body.
=>It is non specific.
=>It consists of the following barriers:XII Class Biology – Resource Material
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Physical barriers:-:-Skin and mucus-coated epithelium of respiratory,gastrointestinal,urinogenital tracts,where in mucus helps in trapping the microbes.
Physiological barriers:-Includes-(a)Acidity of the stomach(b)Lysozyme in saliva-They
prevent the microbial growth.
Cellular barrier:-Includes-(a)Natural killer lymphocytes(b)Neutrophils(C)monocytes
(d)Macrophage –These specialized cells,which phagocytose and destroy the microbes.
Cytokine barrier:-Interferons produced by the viral infected cell protect the non infected cell
from viral infection.
Structure of Antibody
(2)ACQUIRED IMMUNITY:=>The immunity persons acquireds after birth either by contracting the disease or by vaccination.
=>It is pathogen specific(hence called specific or adaptive immunity)
=>It is present only in vertebrates.
=>It has the following characters: Specificity:-It has the ability to distinguish many different foreign molecules.
 Memory:-When the immune system encounters a pathogen for the first time it develops an
immune response by which the pathogen is eliminated,it also retains some memory cells which
evoke a heightened immune response in the further encounters.
 It has the capacity to distinguish between self and the foreign molecules/cell.
 Acquired immunity has two limbes:1. Humoral or antibody mediated immunity
2. Cell mediated immunity(CMI)
(1)HUMORAL IMMUNITY:=>It consists of the antibodies that are circulating in the body fluid.
=>The antibodies produced by B-lymphocytesin response to the antigens are collectively called
immunoglobulins.
=> Immunoglobulins are various types like-IgA,IgD,IgE,IgM,IgG.
=>Each antibody consists of four poly peptide chains ,held together in the form of Y where the tips
of the two upper arms binds to the antigens in a lock and key manner to form antigen –antibody
complex.
=>Two of the peptide chain are long and called heavy(H) chain while the other two are short and
called light (L) chain, hence the antibody is referred to H2L2.
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(2)CELL MEDIATED IMMUNITY:=>It is mediated by T-lymphocyte cell.
=>There are two groups of lymphocytes:1. Cytitoxic/killer T-cells,which kill the specific target cell by a variety of mechanisms.
2. Helper t-cells which activates the specific B-cells to produce antibodies.
=>Acquired immunity also be classified into two types:1. Active immunity
2. Passive immunity
=>Differences between them:Active immunity
1.When the antibodies are developed by
our own cell in response to the antigens,is
called active immunity.
Passive immunity
1. When the antibodies developed in other
vertebrates in response to deliberate
injection of antigen are injected into our
body it constitutes passive immunity.
2.It is used when the immune response has
2.It takes time to develop immunity.
to be faster.
3.It stays for short period e.g.
3.It stays for longer period.e.g.
(a)Immunity given to infant by antibodies
(a)Immunity developed during natural in colostrum.
exposureto pathogens.
(b)Immunity given by tetanus antitoxin.
(b)Immunity developed by vaccination.
VACCINATION AND IMMUNISATION: It is based on the property called memory of the immune system.
 The vaccine generates antibodies that neutralized the toxin/pathogen and also produces
memory B-cell and T-cell which recognize the pathogen in subsequent encounters and
produce antibodies.
 If a quick immune response is needed as in tetanus infection preformed antibodies or
antitoxin is injected into the patient ,this type of immunization is called passive
immunization.
 Recombinant DNA technology has allowed the production of antigenic polypeptide of the of
the pathogen in other microbes like yeast and bacteria,e.g.-hepatitis-B vaccine is produced
using yeast cell.
ALLERGY:=> Allergy can be define as the exaggerated or hypersensitive reaction of the immune system to
certain antigen present in environment.
=> The agent causes allergy is called allergen like-dust , mites, pollen grains,animal danger etc.
=> The antibodies produced in the response to allergens are IgE.
=> Symptoms of allergy:
Sneezing

Watery eyes

Rashes

Running nose
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=>
=>
Difficulty in breathing
These symptoms are produced due to release of histamine and serotonin from the mast cell.
Drugs like antihistamine,adrenaline and steroids quickly reduce the symptoms of allergy.
AUTOIMMUNITY:=> Autoimmune disease are those disorders caused when the bodies immune system goes off the
track and starts destroying self cells and molecules.
 Hashimotos thyroditis,systemic lupus,Rhumatoid arthritis etc.
IMMUNE SYSTEM:=> Function:-To recognize the foreign molecules(antigens),respond to them and keep a memory
of them.
=>
It also plays a role in –organ transplantation,allergic reactions,autoimmune disease
=>
Immune system consists of the following:1. Lymphoid organ:-These are the organ where origin maturation and proliferation of
lymphocytes take place.
=> These are classified into two groups:(a) Primary lymphoid organ:- are those where the immature lymphocyte cells undergo
maturation /differentiation into antigen specific lymphocytes,e.g. Bone marrow and thymus.
(b) Secondary lymphoid organ:-are those where the lymphocytes intract with the antigen and
proliferate to form a clone(effector cells and memory cell)e.g. spleen,lymph
node,tonsils,appendix,payers patches of small intestine
2.Bone marrow:
=> Is the organ where all types of blood cells including lymphocytes are formed.
=> It provides the microenvironment for the development and maturation of
B-lymphocyte .
3.Thymus:=> Thymus is located beneath the chest bone near the heart.
=> This gland keeps reducing in size with age.
=>
It provides the microenvironment for the development and maturation of T-lymphocytes.
4.Spleen:=>
It mainly contains lymphocytes and phagocytes.
=>
It acts as a filter of the blood by trapping blood born microbes.
=>
It is also a reservoir of erythrocytes.
5.Lymph node:-[
=> Lymph nodes are small solid structures found at different points along lymphatic system.
=> They act as a filter and trap the microbes that have entered the lymph.
=> Antigens trapped in them activate the lymphocytes present in the lymph nodes and produce an
immune response.
6.Mucosal-associated lymphoid tissue(MALT):=> Lymphoid tissue located within the mucosal lining of the major
tracts(respiratory,digestive,urinogenital tracts) is called mucosal associated lymphoid tissue.
=> In account for about 50% of lymphoid tissue in the human body.
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AIDS:-(a)General account
- It was first reported in 1981.
- it is caused by Human Immunodeficiency Virus (HIV), which is a retrovirus.
-Transmission of HIV occurs in one or more of the following ways:
(i) By sexual contact with the infected person.
(ii) Transfusion of contaminated blood and blood products.
(iii) Sharing infected needles.
(iv) From infected mother to the child through the placenta.
 The following individuals are at high risk of getting the disease:
(i)Those who have multiple sexual partners.
(ii)Drug addicts taking the drugs intravenously.
(iii)Individuals who require repeated blood transfusion.
(iv)Children born to an infected woman.
(b)Life Cycle of HIV.
-The virus after getting into the body of a person, enters the macrophages.
-The RNA replicates and DNA is formed by reverse transcriptase.
-The viral DNA gets incorporated with the host cell DNA and directs the infected cell to produce
virus particles.
- The macrophages continue to produce virus particles.
-The virus than enters the helper T-lymphocytes, replicates and forms progeny viruses.
-The progeny viruses released in the blood attack other helper T-lymphocytes and there is a
progressive decrease in the number of helper T-lymphocytes in the body of the infected persons.The
person become easily infected by bacteria like Mycobacterium, viruses and even parasites like
Toxoplasma.
-The person is unable to protect himself/herself against any infection.
(c)Prevention of AIDS.
-National AIDS Control Organization(NACO)and non-governmental organizations are trying their
best to educate people about AIDS.
-World Health Organization (WHO) has started a number of programmes to prevent spreading of
HIV infection; some such steps include:
(i) ensuring use of disposable needles and syringes.
(ii) checking blood for HIV.
(iii) free distribution of of condoms and advocating safe sex.
(iv) controlling drug abuse.
(v) promoting regular check-up for HIV in susceptible populations, etc.
-AIDS is diagnosed by ELISA(Enzyme –linked Immuno sorbent Assay) test.
- Treatment with anti-retroviral drugs is only partially effective; they can only prolong the life of the
patient and cannot prevent death.
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17.CANCER
(a) General Account .
-Transformation of normal cells into cancerous cell is induced by carcinogens .
-carcinogens are those physical, chemical and biological and biological agent which bring
about uncontrolled proliferation of cells [cancer].
-cacinogens are of the following type :
(i) physical carcinogens ,e.g.UV rays ,gamma rays
(ii) chemical carcinogen,e.g.,aniline dyes,chemical present in tobacco smoke .
(iii) tumour viruses (oncogenic viruses).
- The cancer cells differ from the normal cells in the following ways :
(i) there is breakdown of the regulatory mechanism which control normal cell growth , division
and differentiation .
(ii) cancer cells do not show contact inhibition ,and show uncontrolled division .
(iii) cancer cells show metastasis ,i.e.,they detach from the tumours and move to distant sites
Through body fluids and develop secondary tumours .
Tumours are of two types:
 BENIGN TUMOURS.
-They remain confined to their original location and do not spread to other parts,they cause
little damage.
 MALIGNANT TUMOURS:-They are masses of neoplastic /proliferating cell, which grow rapidly invade and damage the
surrounding normal tissue /cell.
-These cells compete with the normal cells for vital nutrients and disrupt the normal
metabolism.
-These cells shows the property of metastasis.
(b) Dignosis of cancer:Cancer can be detected by:1. Biopsy and histopathological studies of the tissue.
2. Blood and bone marrow test for increased cell count as in leukaemia.
3. Techniques like radiography ,magnetic resonance and computed tomography for cancer of
internal organ.
4. Use of antibodies against cancer specific antigen.
5. Molecular biology to detect genes in individuals with inherited susceptibility to certain
cancers.
(c)Treatment of cancer:-following methods:1. Surgery:-The tumour cells are surgically removed to reduce the load of cancerous cell.
2. Radio therapy:-The tumour cells are irradiated wholly but taking care of surrounding
normal cell.
3. Chemotherapy:- Certain drugs are used to kill the cancerous cell but majority of drugs
have side effect like hair loss ,anemia.
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4.
Immunotherapy:-This involves the use of biological response-modifiers like alphainterferon,which activate the immune system and help in destroying the tumour.
18. DRUG ABUSE:-Drugs
that
are
commonly
abused
include
opioids,cannabinoids,cocaalkaloids,barbiturates,amphetamines,benzodiazepins and lycergic acid diethylamides.
(a)Kinds of drugs:(i)Opioids:These are the drugs which bind to opioid receptors in central nervous system and
gastrointestinal tract e.g. morphine,heroin.
Morphine is obtain from the latex of poppy plant(papaver somniferum).
It is sedative and pain killer,use to reduce pain after surgery.
Heroin(smack) is chemically diacetyl morphine ,it is a bitter ,white ,odourless , crysteline
compound obtain by acelaration of morphine.
Heroin is generally taken by smoking and injection it is depressant and slow down body
function
(ii)Cannabinoids:These are a group of chemicals , which interact with cannabinoid receptors present mainly in brain.
Natural cannabinoids are obtained from the inflorescence/flower top of Cannabis sativa.
The active component of cannabinoids is delta-9-tetrahydrocannabinol (THC).
Marijuana, hashish ganja and charas are also produced by various combinations of flower tops ,
leaves and resin of Cannabis plant.
These are taken by inhalation and oral ingestion; they affect the cardiovascular system of the body.
They are abused by sportpersons in recent times .
(iii) Coca Alkaloids / Cocaine.
 It is obtained from Erythroxylon coca.
 Cocaine interferes with the transport of the neurotransmitter, dopamine.
 It is usually taken by smoking.
 It has potential stimulating action on the central nervous system and prouduces a sense of
euphoria and increased energy ; excessive dosage hallucinations.
(iv) Hallucinogens.
Products from plants like Atropa bellodona and Datura spp. Are hallucinogenic.
LSD (Lysergic acid Diethylamide) is obtained from a fungus.
(iv) Tobacco.
Tobacco is usually chewed or smoked or used as snuff.
It contains mainly nicotine ,which is a stimulant and toxin.
Nicotine stimulates the adrenal gland to relese adrenaline and non-adrenaline which increase the
blood pressure and heart rate.
Smoking of tobacco increases the chances of lung cancer, bronchitis, emphysema, coronary heart
diseases cancer of throat, gastric ulcer, cancer of urinary bladder, etc.
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Smoking of tobacco also increases the carbon monoxide content of blood and redusec concentration
of haem-bound oxygen, thus causing oxygen deficiency in the body .
 Chewing of tobacco causes oral cancer.
(iv) Alcohol.
 Alcohol is a depressant.
 It affects the central nervous system.
(b) Addiction and Dependence.
- following are causes of drug / alcohol abuse :
Curiosity, (ii) need for adventure, (iii) excitement (iv) experimentation (v) to escape from stress and
(vi) unsupportive family structure.
With repeated use of drugs/alcohol, the tolerance level of the receptors in our body increases and
consequently they respond only to higher doses of drugs/alcohol.
If the regular dose of drugs/alcohol is abruptly discontinued, the body manifest characteristic and
unpleasant withdrawal symptoms , which can be anxiety , nausea, sweating, etc.
(c) Effects of Drug/Alcohol Abuse.
The immediate effects of drugs/alcohol abuse are manifested as reckless behavior, vandalism
and violence .
Excess doses can lead to coma and death due to cerebral haemorrhage, respiratory and heart
failure.
A combination of drugs or their intake with alcohol leads to death.
The most common warnings signalsof drug/alcohol abuse include :
(i)
Drop in academic performance .
(ii) Lack of interest in personal hygene.
(iii) Withdrawal and isolation from family and friends .
(iV)
Aggressive and rebellious behavior.
(v)
Lack of interest in hobbies.
(iv)
Change in sleeping and eating habbits .
(vii) Fluctuations in weight, etc.
When drug is taken intravenously it can lead to infections like AIDS and hepatitis.
Use of alcohol during adolescence can lead to heavy drinking in adulthood.
Chronic use of drug and alcohol damages central nervous system and liver.
Misuse of anabolic steroid causes the following in females:(1)
Masculinisation
(2)
Increase aggressiveness
(3)
Mood swing
(4)
Abnormal menstrual cycle
(5)
Excess hair growth on the face and body
(6)
Deepening of voice etc.
(7)
Enlargement of clitoris.
Misuse of anabolic steroid causes the following in males:(1)
Acne
(2)
Increased aggressiveness
(3)
depression
(4)
Reduction in size of testicles
(5)
Premature baldness
(6)
Enlargement of prostrate gland
(7)
Enlarged breast etc.
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Prevention and control:(1)
(2)
Avoid undue peer pressure.
Educating and counseling to face problems and stress and to accept failures and
disappointments as a part of life.
(3) Seeking help from parents and peers could help to vent their feelings of anxiety and guilt.
(4) Looking for danger signs would help in initiating proper remedial steps or treatment.
(5) Seeking professional and medical help for deaddiction and rehabilitation would help individual
to come out of the problem completely.
1.Animal husbandry:

Animal husbandry deals with the care and breeding of livestock
that are useful to human beings.
It is estimated that more than 70% of the world livestock population is in India and china, but
its contribution to the world farm produce is only 25%.
Hence the additional conventional practices of animal husbandry new technologies must also
be applied to achieve improvement in quality and productivity.
2. Dairy farm management
1].
Milk yield is dependent primarily on the quality of breed
2].
Consequently selection of good breed ( having high yielding potential combined with
resistance to disease ) is very important.
3].
the following are necessary for realizing the yield potential:
(a).
the animal has to be provided with proper shelter.
(b).
feeding of cattle should be done in scientific manner, considering the quantity and quality of
fodder.
(c)
it should be given sufficient quantity of water.
(d).
the animal must be maintained disease –free.
(e).
stringent cleanliness and hygiene of both the cattle and handler are very important.
3.
poultry farm management
1].
poultry typically includes chicken and ducks and sometimes turkey and geese.
2].
The important components of poultry farm management includes:
(a).selection of disease –free and suitable breed.
(b).proper feed and water for birds.
(c).proper safe farm condition.
(d).hygiene and health care of the birds
3. Bee-keeping /apiculture
1]. the honey bees are mainly maintained for the production of
honey and beewax .
2]. Honey is used as:
(a) food of high nutritive value and
(b) medicine in ayurveda
3]. Beewax is used in industry for the preparation of cosmetic and polishes .
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4]. the most common species of honey bee is {apis indica}
5]. Bee-keeping can be practiced in an area were there are sufficient bee pastures (some wild
shrubs , cultivated crop ,fruit –orchard, etc.)
6]. Beehives can be kept any place like courtyard , verandah or on the roof of the house.
7]. Bee-keeping is relatively easy and required the following consideration :
(a) knowledge of the nature and habits of bee.
(b) selection of keeping beehives.
(c) catching and hiving of swarms.
(d) management of beehives during different season .
(e) handling and collection of honey and beewax .
8]. Bees are the pollinators of many crop plants ( apple , pear, sunflower, Brassica etc.) and
hence keeping beehives in crop field during seasons increase pollination efficiency and thereby
improves the yield.
5. Fisheries.
1]. It is an important industry for the following reasons:
(a) A large number of people of depends of fish and fish products .
(b) it provides income and employment to millions of fishermen in the coastal states.
(c).products like fish-liver oil are of medicinal valve.
2].
some common fresh water fishes are catla , rohu, common carp, etc.
3].
some common marine fishes are hilsa, sardines, mackerel and pomfrets
6.
Animals Breeding.
1]. Animals breeding aims at:
(a) Increasing the quantity of yield.
(b) Improving the quality of the produce.
 Breeding is of the following types:BREEDING
 Inbreeding
 Outbreeding:-1.Outcrossing
2.Cross-breeding
3.Interspecific hybridization
 Inbreeding
 The breeding strategy includes the identification of superior males and females of the same
breed and mating them in pairs.
 The progeny of such matings are evaluated and superior males and females are identified for
further mating.
 Inbreeding increases homozygosity and thus inbreeding is necessary for evolvinga pure line in
any animal.
 Inbreeding exposes the harmful recessive alleles, which become eliminated by selection.
 Inbreeding also helps in accumulation of superior genes and elimination of less desirable genes.
 But continued inbreeding causes inbreeding depression, that reduces fertility and even
productivity.
 Under such a situation the selected animals of the breeding population are mated with
unrelated superior animals of the same breed to restore fertility and yield.

Outbreeding

Outbreedinng refers to the breeding of unrelated animals either of the same breed or of
different breeds or even different species.
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

Outbreeding is of the following types:OUTCROSSING.
o Out crossing is the practice of mating of animals of the same breed , but that have no
common ancestors on either side of their pedigree up to 4-6 generations.
o The offspring of out crossing is called an outcross.
o A single outcross helps to overcome inbreeding depression.
o It is the best breeding method for animals that are below average in productivity and growth
rate.
 CROSSBREEDING
o It is a method of outbreeding in which superior males of one breed are mated with the
superior females of another breed of the same species.
o This helps in combining the desirable qualities of the two different breeds into the progeny.
o The hybrid progeny may be directly used for commercial production or they may be
subjected to some form of inbreeding and selection , to develop new stable breeds.
o One example of cross-breeding is hisardale , a new breed of sheep developed by crossing
Bikaneri ewes and Marino rams
 INTERSPECIFIC HYBRYDISATION
It is a method of outbreeding in which male and female animals of two different species are
crossed to combine the desirable features of both the parents into one, e.g., mule is produced
by a cross between a male donkey and female horse.
7.Artificial Insemination.
1.)
It is the process in which the semen collected from a superior male is injected into the
reproductive tract of the selected female by the breeder
2.)
The advantage of this practice are:
(1)
Semen can be used immediately or stored/frozen and used at a later date when the female is
in the right reproductive phase.
(2)
Semen can be transported in the frozen from to a distant place where the selected female
animals are present.
(3)
Semen from one selected male animal can be used on a number of female animals.
3.)
The disadvantage is that the success rate is fairly low.
8. Multiple Ovulation Embryo Transfer (MOTE)
1.)
2.)
(1)
(2)
(3)
3.)
4.)
It is a method to improve the herds.
The steps in the method are follows:
A cow is administered hormones (like FSH) to induce follicular maturation and super
ovulation i.e. production of 6-8 ova in one cycle.
The cow is mated with the selected bull or artificially inseminated.
The fertilized eggs at 8-32- celled stage are recovered and transferred to surrogate mother
This technology has been used for cattle, rabbits, mares, etc.
High milk-yielding breeds of females and high quality meat-yielding bulls have been bred
successfully to increase the herd size in short time.
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9. Plant Breeding.
1.)
Conventional or traditional plant breeding has been practiced for thousands of years and most
of our present day crops-are the result of domestication.
2.)
Classical plant breeding involves hybridization of pure lines and to select the plants with
desirable qualities.
3.)
The list of traits that breeders have tried to incorporate into crop plants is as follows:
(1) High yield.
(2) Better quality of the producer.
(3) Increased tolerance to environmental stresses.
(4) Resistance to pathogens (diseases)
(5) Increased tolerance to insects pests.
4.)
The main steps in breeding a new genetic variety of a crop are:
(1) Collection of variability or germplasm collection.
(2) Evaluation and selection of parents.
(3) Cross-breeding or hybridization of the selected parents.
(4) Selection and testing of superior recombinants.
(5) Testing, release and commercialization of new cultivars.
(1) Collection of variability.
= Collection and preservation of all the different wild varieties ,species and relatives of the
cultivated species is a pre-requisite for effective exploitation of natural genes available in the
population this collection constitutes the germplasm.
(2) Evaluation and selection of parents.
= The germplasm collected is evaluated to identify plants with desirable characters.
= The selected plants are multiplied and used in the process of hybridization.
= Pure lines are created (by repeated self-pollination) wherever possible and desirable.
(3) Hybridization of the selected parents.
= The selected parents are hybridized, so that the traits in them can be combined in the
hybrid progeny.
= Hybridization is a time consuming and tedious process it may not necessarily result in
combination of all the desirable characters.
(4)Selection and testing of superior recombinants:-Individual with desired combination of character have to be selected from among the
progeny of hybrid.
-Such hybrids are superior to both the parents (Hybrid vigour/Heterosis).
-They are self pollinated to several generations till they reach a state of homozygosity (pure
line),so that there will be no segregation of characters in the progeny.
(5) Testing ,Release and commercialization of new cultivers:(a)Evaluation:-The selected lines are evaluated for their yield and other agronomic traits ,disease resistance etc.
-Evaluation is done by growing these plants in the research fields, and recording their performance
under ideal conditions of irrigation,application of fertilizers,and other crop management practice.
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(b) Testing:-Evaluated plants are tested in the farmers fields for at least three growing seasons,at several
locations of the country,representing different agroclimatic zone where the crop is normally
grown.
-The material is evaluated in comparison to the best available local cultivar as a reference
material.
(6)Release:-The material thus selected is certified and released as a new variety.
Green revolution:-Agriculture account for 33% of India GDP and employs62% of the population.
(i) Wheat:-Wheat production has increased from 11 million tons in 1960 to 75 million tons in 2000.
-This is due to development of semidwarf varieties.
-Norman E. Borlaug developed semidwarf varieties of wheat at the international centre for
wheat and maize improvement in Mexico.
-Sonaand and kalian sona selected from these semidwarf varieties were introduced in India
,they were high yielding and disease resistance.
(ii)Rice:-Rice production increased from 35 million tons in 1960 to 89.5 million tons in 2000.
-Semidwarf rice varieties were derived from IR-8 and Taichung Native-1.
-The derivatives were introduced in India 1966.
-Better yielding semidwarf varieties like jaya and ratna were developed in India.
(iii)Sugarcane:-Saccharum barberi,origionally grown in north India had poor sugar content.
-Saccharum officenarum,grown in south India has thicker stem and higher sugar content.
-Cross has made between these species and the hybrid variety combining the desirable
qualities like thick stem high sugar content and high yield is being grown in North India.
(iv)Millet:-Several hybrid varieties of maize ,bajra and jowar have been developed in India.
-These breeding programmes have result in the development of high yielding varieties that
are resistance to water stress.
11.Plants Breeding for Disease Resistance
Plants breeding for diseases has two advantages:
Enhanced food production by reducing losses due to diseases.
Reduced dependence on use of fungicides and bactericides.
Resistance of plant to a diseases is genetically determined and it is the ability of the host plant to
prevent the pathogen from causing the diseases
Diseases in crop plant is caused by viruses, bacteria and fungi.
Some examples are as follows:
Viral diseases-Tobacco mosaic, Turnip mosaic.
Bacterial diseases-Black rot of crucifers, citrus canker, blight of rice.
Fungal diseases-Rust of wheat, Red rot of sugarcane, Late blight of potato.
The conventional method of breeding for resistance includes the following steps;
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Screening the germplasm for the resistant sources.
Hybridization of selected parents.
Selection and evolution of hybrids.
i.
Testing and release of new varieties.
The resistance-gene may be present in wild relatives, which are low yielding; hence the gene for
resistance has to be incorporated into the better yielding variety by hybridization, e.g, the gene for
resistance to yellow mosaic virus found in a wild species of bhindi (Abelmoschus maniholtand)
has been transferred to raise a new variety of Abelmoschus esculentus, called parbhani kranti .


Some of the crop varieties that are resistant to diseases have been raised by hybridization and
selected; a few examples are given:
S.No.
Name of the crop
Name of the variety
Resistance to disease(s)
1.
Cauliflower
Pusa subhara Pusa Snowball K-1
Black rot and
blight B lack rot
2.
Wheat
Himgiri
Leaf and stripe rust and
Hill bunt
3.
Brassica
Pusa swarnim
Wheat rust
4.
Cow pea
Pusa Komal
Bacterial blight
5.
Chilly
Pusa Sadabahar
curl
Chilly mosaic, Tobacco
mosaic and Leaf curl
Currently mutation breeding is being carried out for diseases resistance, as there is limited
availability of disease-resistance genes in the crop plants and their wild relatives.
By mutation, disease-resistance gene(s) is/are created.
Mutation breeding involves following steps:
Inducing mutation(s) through various methods/mutagens.
Screening the plant materials for disease-resistance.
Multiplication of these selected plants for direct use or for use in breeding.
Hybridization of these selected plants materials.
Selection for disease-resistance, testing and release as a variety.

Through mutation breeding, varieties of mung bean have been developed that are resistant to
yellow mosaic virus and powdery mildew.
12.Plant Breeding for Resistance to Insect Pests.

Resistance to insect pests is also genetically controlled and manifested in the form of
morphological, physiological or biochemical characterstics.
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. A few examples of such characteristics and the resistance to pests are given in the following table :
s.no. Name
of Characteristics
Resistance to pest
crop
(s)
1.
wheat
1)hairy leaves
Cereal leaf beetle
2)solid stem
sawfly
2.
cotton
1)hairy leaves
Jassids bollworm.
2)smooth
leaves
and nectar less
condition
3.
Maize
1) High aspartic Stem borer.
acid
and
low
nitrogen and sugar
contents.
. Breeding for pest –resistance involves the same steps as breeding for disease-resistance.
.the first step is to locate the source of resistance in the germ plasm collection.
.the following are good sources of resistance:
1) Cultivated varieties
2) Wild relative species
3) germplasm collection.
.some of the pest-resistance crop varies developed by hybridization and selection are
presented in the following table:
s.no. Name of the crop Name
of
the Resistance to pets
variety
(s)
1)
Okra(bhindi)
Pusa sawani, pusa Shoot and fruit borer
a-4
2)
Brassica(repeseed) Pusa gaurav
Aphids
3)
Falt bean
Pusa stem-2, pusa Jassids, aphids and
stem-3
fruit borers
13. Plant breeding for improved food quality:
. Consumption of food lacking in essential micronutrients can lead to diseases,reduced life
span and reduced mental abilities.
. Consequently one of the method for developing crop with higher levels of these nutrients is
biofortification.
. The objectives of breeding improved nutritional quality of crops are to increase the
following:
1) Protein content and quality.
2) Oil/fat content and quality.
3) Vitamin content.
4) Mineral nutrients.
. Some examples of crop varieties, with increased nutritional qualities, that have been
developed and released in India, are given below:
1) Lysine and tryptophan rich varieties of maize.
2) High protein variety of wheat.
3) Iron fortified variety of rise.
4) Vitamin C- enriched variety of bitter gourd, tomato, bathua.
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5) Iron and calcium- enriched variety of spinach and bathua.
6) Protein- enriched variety of beans like, French beans, Lablab beans, broad bean and garden peas.
7) Vitamin A-enriched variety of carrot, spinach and pumpkin.
SINGLE CELL PROTEIN
Microbes are grown on an industrial scale and processed and used as nutrient rich
food.
1.
2
3.
4.
Spirulina is an example.
The advantages are that :
SCPs are rich in proteins and low in fats .
.they can be easily grown on cheaper materials like wastewater from potato processing
plants,animal manure,molasses,etc.
the use of waste materials reduces pollution.
they reduce the pressure on agriculture[for supply of pesticides ,fertilizers etc.]e.g.
,methylophilus ,methylotrophus bacterium has been used to produce very high quantity of
proteins.
TISSUE CULTURE
It is the technique of regeneration of whole plants from any part of a plant by growing it on a
suitable culture \nutrient medium under aseptic\sterile conditions in vitro.
The culture medium must supply the energy ,inorganic nutrients,vitamins,amino acids and
growth regulators like cytokinins and Auxins.
By this method ,called micropropagation ,thousands of plants can be grown in a short period
of time .
The plants produced are genetically identical and constitute somaclones.
The advantages of micropropagation are :
1.A number of plants can be grown in a short period of time.
2.healthy disease free plants can be grown by meristem culture.
3.somatic hybrids can be raised by tissue culture, where sexual hybridization is not possible.
SOMATIC HYBRIDISATION
Somatic hybridization is the process of fusing protoplasts of somatic cells derived from two
different varieties or species of plants ,on a suitable nutrient\culture medium ,under aseptic
\sterile conditions .
The process includes following steps :
1.Isolation of protoplasts by digesting the cell wall by use of enzymes.
2.fusion of protoplasts of the selected varieties.
3.growth of the fused protoplasts on suitable culture medium ,where they develop cell
wall,become cell,multiply and differentiate toform somatic hybrids .
One example of a somatic hybrid is pomato,produced by fusion of protoplasts of tomato and
potato ; but this plant has not all the desired qualities for its commercial –scale production.
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MICROBES IN HUMAN WELFARE

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

Micribes are small orgsnisms which being small(less than 0.1 mm).
Microbes are not visible with naked eye.
They belongs to all group of organism-bacteria,protista,fungi,plants,animals.
Microbes occurs every where-in air,soil,water,on and inside of bodies of other organism,inside
thermal vents or geysers with temperature of 100 C,Under several meters thick snow where
temperature is several digrees below than 0 C,highy saline or extremely acidic environment and
deep soil.
1. MICROBES IN HOUSE HOLD PRODUCTS:

LAB-(lactic acid bacteria)
List of some microbes ,their scientific name and house hold products:Microbes
Scientific Name
Bacteria
lactobaccillus
Bacteria
Streptococcus
faecalis
Saccharomyces
cerevisiae
Propionibacterium
sharmanii
Yeast
Bacteria




House
hold
product
Making
curd
from milk
Dosa and idli
Bread
Swiss cheese
“TODDY”-is a traditional drink of some parts of southern India is made by fermenting sap
from palms.
The puffed-up apperence of dough is due to the production of co2 gas.
Large hols in swiss chees are due toproduction of lareamount of co2.
THE Roquefort cheese are ripend by growing a specific fungi on them,which gives them a
particular flavour.
2. Microbes In Industrial Products:Even in industry , microbes are used to synthesise of product valuable to human beings.
Beverages ,antibiotics and chemical,enzymes and other bioactive molecules are some examples.
2.1 Fermented beverages
 Production on an industrial scale , requires growing microbes in very large vessels called
Fermentors.
 The yeast Saccharomyces Cerevisiae commonly called Brewer’s yeast is used in beverages.
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
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It is used in fermenting malted cereals and fruit juices, to produce ethanol, wine, beer, whisky
,brandy or rum.
Distillated beverages:- whisky, brandy and rum.
Non distillated beverages:- wine and beer.
Diagram of Fermentors:-
2.2 Antibiotics
 The term antibiotics is derived from the Greek words ‘anti’-against and ‘bios’-life and literally
means against life (with reference to diseases causing organisms).
 Defination:- Antibiotics are chemical substances , which are produce by some microbes and
can kill or retard the growth of other (diseases –causing) microbes.
 Penicillin is the first antibiotics to be discovered by Alexander Fleming, while working on
Staphyloocci bacteria, but its potential as an effective antibiotic was established later by Ernst
Chain and Howard Florey.
 Penicillin was obtained from the fungus (a mould) Penicillin Notatum.
 Antibiotics are used to treat a number of diseases like diphtheria , leprosy, pertusis (whooping
cough),plague, ect.
Antibiotic
Source
Action
Penicillin
Penicillium chrysogenum
Tonsillitis ,Sore throat,
Gonorrhoea,Rheumatic
fever,some
Pneumonia
types
Griseofulvin
Penicillium griseofulvum
Antifungal, especially for
Ringworm.
Neomycin
Streptomyces fradiae
Antibacterial against Gram
(-) bacilli and Gram (+)
bacteria.
2.2 Organic acid and alcohol
 The following table gives a list of organic acid and the microbe employed in their production.
Organic acid
Microbes
1.
Citric acid
Aspergillus niger (fungus)
2.
Acetic acid
Acetobacter aceti (bacteriaum)
3.
Butyric acid
Clostridium butylicum (bacteriaum)
4.
Lactic acid
Lactobacillus delburekii (bacterium)
5.
Ethanol
Saccharomyces cereviseae (fungus)
2.3 Enzymes
 The enzymes produced with the help of microbes are:(a) Lipases (b) Proteases (c) Pactinases.
 Lipases are used in detergent formulation and are helpful in removing oily stains from the
laundry.
 Pactinases and proteases are used to clear the fruit juices during bottling.
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
Streptokinase produced by Streptococus and modified by genetic engineering is used as ‘clot
buster’ , for removing the blood clots from the blood vessels of patients suffered from
myocardial infraction.
2.4 Bioactive molecules
Bioactive molecules
Cyclosporine A
Source
Trichoderma
(fungus)
Stains
Monascus purpureus(yeast)
polysporum
Action
It is used as an immuno
suppressive agent during
organ transplantation.
It is used for lowering of
blood cholesterol, as it act
as a competitive inhibitor
of the enzyme involved in
cholesterol synthesis.
2.5 Microbes in sewage treatment
 The municipal waste water(called sewage )contains:-large amount of organic material and
microbes(many are pathogenic and some are heterotrophs.
 The sewage is treated in sewage treatment plants(STPs) before it is discharged into water bodies
to reduce the pollution load.
 The treatment involes two steps:-1.Primary treatment 2.Secondary treatment
1. Primary treatment:









This is a physical process of removal of small and large particles though filtration and
sedimentation.
The first steps is to remove floating objects(like polythene bags)by letting the sewage to pass
through wire mesh screens of sequentially smaller pore sizes.
Then sewage is passed into grit chamber, where grit is sedimented.
The sewage is allowed to go into the primary settling tank ,where the suspended materials settle
down from the primary sludge.
The effluent is taken for secondary treatment.
2. Secondary treatment:It is biological process , that employs the heterotrophic bacteria naturally present in sewage.
The effluent from primary treatment is passed into large aeration tank , where it is constantly
agitated and air is pumped into it.
This allows the rapid growth of aerobic microbes into flocs ,which consume the organic matter
of the sewage and reduce the biological oxygen demand(BOD).
When the BOD of the sewage is reduced significantly , the effluent is passed into settling tank
where the flocs are allowed to sediment forming the activated sludge.
A small part of activated sludge is pumped back into the aeration tank as inoculums.
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The remaining part of the sludge is pumped into anaerobic sludge digester where the anaerobic
bacteria digest the bacteria and fungi in the sludge producing methane , hydrogen sulphide ,and
carbon dioxide.
The effluent after secondary treatment is released into water bodies like rivers and streams.
The programs like Ganga action plans and Yamuna Action plan ,initiated by the ministry of
environment and forest ,depend on sewage treatment before that is released into these rivers.
2.6 Microbes in production of biogas
 Bio gas predominantly contains methane (60%) and remaining 40% is of carbon dioxide.
 Methanogens like Methanobacterium produce large quantities of methane ,along with carbon
dioxide and hydrogen by an acting of cellulosic compound.
 They are found in:1. The anaerobic sludge
2. rumen of cattle
3. Flooded rice fields
4. Marshy places
 Cattle dung is used for production of biogas as it contains cellulosic material as well as
methanogens.
 Production of biogas:1. The biogas plant consists of 10-15 feet deep concrete tank in which the slurry of the dung is fed.
2. The floating cover is placed over the slurry, which keeps on rising as the gas is produced in the
tank by the microbial activity.
3. The biogas plant has an outlet that is connected to a pipe ,for removal of biogas and supply of it
to the required place.
4. There is also an outlet to remove the spent slurry, which can be used as fertilizer.
2.7 Microbes as biocontrol agents
 Biocontrol refers to the use of biological method for controlling plant diseases and pest.
 It decreasese the use of insecticide and pesticides.
 These chemicals are extremely harmful to human beings ,animals and our environment,
 An organic gardener works to create a system where the insects (that are pests)are not
eradicated, but are kept at manageable levels by a complex system of checks and balance within
the ecosystem.
 The beneficial predatory and parasitic insects which depend on these insect pests are able to
survive ,for ex; ladybird beetle is useful to get rid of aphids and dragonflies control mosquito,
 Bacillus thuringiensis is a bacterium whose spores are toxic to certain insect larvae and kill them
but it is not harmful to other insects.
 The toxin producing genes of this bacterium are transferred (genetic engineering )into crop
plants which becomes resistance to insect pests ,ex-Bt cotton.
 Another biological control being developed for treatment/control of plant disease is the fungus
Trichoderma which is free living in soil and root ecosystem and is effective against several plant
pathogen.
2.8 Microbes as biofertilisers
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Bacteria , cyanobactria and fungi (mycorrhiza) are the three group of organism used as
biofertilisers
(a) Bacteria
 Symbiotic bacteria Rhizobium
 Free –living bacteria Azospirillum and Azotobacter.
 They fix the atmospheric nitrogen and enrich soil nutrients.
(b) Fungi: Fungi shows symbiotic association with roots of higher plants called mycorrhizq.
 Many members of genus Glomus fome mycorrhiza.
 Benefits of such associations are:1. The fungal fungal symbionts in these associations absorbs phosphorous from soil and passes it
to the plant.
2. Such associations shows resistance root born pathogens.
3. Tolarance to salinity and droughts.
4. An over all increase in plant growth and development.
(C)Cynobacteria:





These are autotrophic microbes.
Widely distributed in aquatic and terrestrial environments.
Many of which can fix atmospheric nitrogen.
In paddy fields cynobacteria serves as a important biofertilizer.
Blue green algae also add organc matterto the soil and increase its fertility.
Examples of cyanobacteria -Anabaena ,Nostoc ,Ocillatoria etc.
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