Cell the unit of life

 

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Reagents

ORGANIC REAGENT WITH ITS USES👈🏻Clickhere 

MICROBES IN HUMAN WELFARE:

 MICROBES IN HUMAN WELFARE: 

CHAPTER AT A GLANCE

Microbes	Group	Uses
1.         Acetobacter aceti	Bacterium	Acetic acid
2.         Aspergillus niger	Fungus	Citric acid
3.         Azospirillum	Bacterium	Nitrogen fixation, biofertilizer
4.         Azotobacter	Bacterium	Nitrogen fixation, biofertilizer
5.         Bacillus thuringiensis (Bt)	Bacterium	Biocontrol of butterfly caterpillar
6.         Baculoviruses (mainlynucleopolyhedrovirus)	Virus	Biocontrol of insects and other arthropods. Used in Integrated Pest Management (IPM).
7.         Clostridium butyilicum	Bacterium	Butyric acid
8.         Cyanobacteria (blue green algae)	Bacteria	Nitrogen fixation, biofertilizer
9.         Lactobacillus (LAB)	Bacterium	Lactic acid, milk to curd
10.     Methanobacterium (methanogens)	Bacterium	Biogas (CH4) production i.e., source of energy
11.     Monascus purpureus	Fungus (a yeast)	Statins (blood cholesterol lowering agents)
12.     Mycorrhiza	Fungi (E.g.Glomus) + plant	Biofertilizer
13.     Penicillium notatum	Fungus (mould)	Penicillin (First antibiotic discovered by Alexander Fleming).
14.     Penicillium roqueforti	Fungus	Roquefort cheese
15.     Propionibacterium shermanii	Bacterium	In Swiss cheese formation
16.     Rhizobium	Bacterium	Nitrogen fixation, biofertilizer
17.     Saccharomyces cerevisie (Baker’s yeast or Brewer’s yeast)	Fungus	Production of beverages, bread by fermenting dough, ethanol etc.
18.     Streptococcus	Bacterium	Streptokinase (a clot buster)
19.     Trichoderma polysporum	Fungus	Cyclosporine A (An immunosuppressive agent)
20.     Trichoderma sp	Fungus	Biocontrol

• / Lipases: Used in detergent to remove oily stains from the laundry. 
• Pectinases & Proteases: To clarify bottled juices. 

Steps of Sewage treatment: 

• STP: Sewage Treatment Plant. 
• BOD: Biochemical Oxygen Demand (amount of O2 needed to oxidize all organic compounds in 1 litre of water.

Biogas Plant:

Technology of biogas production in India was developed by: 

• IARI: Indian Agricultural Research Institute 
• KVIC: Khadi & Village Industries Commission. 

STRATEGIES FOR ENHANCEMENT IN FOOD PRODUCTION

 STRATEGIES FOR ENHANCEMENT IN FOOD PRODUCTION: 

CHAPTER AT A GLANCE

I. ANIMAL HUSBANDRY

Scientific agricultural breeding practice and raising livestock. 

1. Dairy Farm Management (Dairying): 

• For increasing yield and quality of milk and its products. 
• Ways for the yield potential: Look after the cattle, Feeding of cattle in a scientific manner, Cleanliness and hygiene. 

2. Poultry Farm Management: 

Its components are: 

• (i) Selection of disease free & suitable breeds. 
• (ii) Proper and safe farm conditions. 
• (iii) Proper feed and water. 
• (iv) Hygiene and health care.

Animal Breeding

Modification of genotype of an organism to make it more useful to humans. E.g. Jersey (cattle), Leghorn (chicken). 

2 types: Inbreeding and out-breeding. 

a) Inbreeding: 

Mating of closely related individuals within the same breed for 4-6 generations. This strategy is as follows: 

• Identify and mate superior males & females of same breed. 
• Evaluate the progeny obtained and identify superior males and females among them for further mating. 

Advantages of Inbreeding: (i) Increases homozygosity. (ii) Exposes harmful recessive genes that are eliminated by selection. (iii) Helps in accumulation of superior genes. 

Inbreeding depression: Reduction in fertility and productivity due to continued inbreeding. To solve this problem, mate selected animals with unrelated superior animals of the same breed.  

b) Out-breeding: 

Breeding of the unrelated animals. 3 types: 

1. Out-crossing: Mating within the same breed, but having no common ancestors up to 4-6 generations. The offspring of such a mating is known as out-cross. Best method for animals having low milk productivity, growth rate in beef cattle, etc. It overcomes inbreeding depression. 

2. Cross-breeding: Mating of superior males of one breed with superior females of another breed to combine desirable qualities. E.g. Bikaneri ewes X Merino rams = Hisardale (sheep). 

3. Interspecific hybridization: Mating of male and female of two different species. E.g. Mule (male ass X female horse). 

Controlled breeding experiments 

1. Artificial insemination: Injection of semen from male parent into the reproductive tract of selected female. 

2. Multiple Ovulation Embryo Transfer Technology (MOET): A cow is administered hormones such as FSH to induce follicular maturation & super ovulation. The animal is either mated with an elite bull or artificially inseminated. Fertilised eggs at 8–32 cells stage are recovered and transferred to surrogate mothers. 

Bee-keeping (apiculture)

Maintenance of honeybees to produce honey and beeswax. 

Most common species: Apis indica. 

Important points for successful bee-keeping: 

• Knowledge of the nature and habits of bees.
• Selection of suitable location for beehives.
• Catching and hiving of swarms. 

Fisheries

An industry of catching, processing or selling of fish, shellfish or other aquatic animals. 

Freshwater fishes: Catla, Rohu, common carp etc. 

Marine fishes: Hilsa, Sardines, Mackerel, Pomfrets etc. 

Aquaculture: farming of aquatic organisms. Pisciculture: farming of fishes. 

Blue Revolution: The development of the fishery industry. 

II. PLANT BREEDING

Manipulation of plant species to create desired plant types for better cultivation, better yields and disease resistance. 

Green Revolution: The development and flourishing of the agriculture. It was dependent on plant breeding. 

Desirable traits for plant breeding: 

• Increased crop yield and quality. 
• Increased tolerance to environmental stresses, resistance to pathogens and insect pests. 

Steps of Plant breeding: 

1. Collection of genetic variability from wild relatives: The entire collection of plants/seeds having all the alleles for all genes in a crop is called germplasm collection. 
2. Evaluation and selection of parents from germplasm. 
3. Cross hybridisation of the selected parents with desired characters to produce hybrid. Limitations: Very time-consuming and tedious process, Hybrids may not combine the desirable characters. 
4. Selection & testing of superior recombinants: These are self-pollinated for several generations till they reach a state of uniformity (homozygosity), so that the characters will not segregate in the progeny. 
5. Testing, release & commercialization. 

Norman E. Borlaug developed semi-dwarf wheat. 

Sonalika & Kalyan Sona: High yielding & disease resistant wheats. 

Semi-dwarf rice varieties were derived from IR-8, (developed at International Rice Research Institute (IRRI), Philippines) and Taichung Native-1. 

Jaya & Ratna: Semi dwarf varieties developed in India. 

Sugar cane: Saccharum barberi X S. officinarum → hybrid sugar cane. 

Plant Breeding for Disease Resistance

Some plant diseases

Fungal: Rusts	Brown rust of wheat, Red rot of sugarcane, Late blight of potato
Bacterial	Black rot of crucifers
Viral	Tobacco mosaic, Turnip mosaic

Methods of breeding for disease resistance:

1. Conventional breeding: 

Some crop varieties bred by Conventional method 

The steps are: 

• Screening germplasm for resistance sources. 
• Hybridisation of selected parents. 
• Selection & evaluation of the hybrids. 
• Testing and release of new varieties.

Some crop varieties bred by Conventional method
Crop	Variety	Resistance to
Wheat	Himgiri	Leaf & stripe rust, hill bunt
Brassica	Pusa swarnim (Karan rai)	White rust
Cauliflower	Pusa Shubhra, Pusa Snowball K-1	Black rot & curl blight black rot
Cowpea	Pusa Komal	Bacterial blight
Chilli	Pusa Sadabahar	Chilly mosaic virus, Tobacco mosaic virus & leaf curl.

2. Mutation breeding: The breeding by mutation using chemicals or radiations to produce plants with desirable characters. 

E.g. In mung bean, resistance to yellow mosaic virus and powdery mildew were induced by mutations. 

Resistant genes from wild species have introduced into high-yielding varieties. E.g. In bhindi (Abelmoschus esculentus), resistance to yellow mosaic virus was transferred from a wild species. It resulted in a new variety called Parbhani kranti. 

Plant Breeding for Developing Resistance to Insect Pests

Morphological, biochemical or physiological characteristics give insect resistance in host crop plants. E.g. 

• Hairy leaves: E.g. resistance to jassids in cotton and cereal leaf beetle in wheat. 
• Solid stems in wheat → non-preference by the stem sawfly. 
• Smooth leaved and Nectar-less cotton varieties → do not attract bollworms. 
• High aspartic acid, low nitrogen and sugar content in maize → resistance to maize stem borers. 

Some crop varieties bred for insect pest resistance:

Crop	Variety	Insect pests
Brassica (rapeseed mustard)	Pusa Gaurav	Aphids
Flat bean	Pusa Sem 2, Pusa Sem 3	Jassids, aphids & fruit borer
Okra (Bhindi)	Pusa Sawani, Pusa A-4	Shoot and Fruit borer

Plant Breeding for Improved Food Quality

Breeding crops with higher levels of nutrients is called Biofortification. E.g. 

Maize hybrids	Twice amount of amino acids, lysine & tryptophan.
Wheat variety, Atlas 66	High protein content
Iron-fortified rice variety	Five times as much iron as in common varieties
Vegetables rich in vitamins & minerals	By Indian Agricultural Research Institute, New Delhi

SINGLE CELL PROTEIN (SCP)

It is the protein derived from single-celled organisms. 

It is an alternate source of proteins for animal and human nutrition. E.g. microbes like Spirulina. 

Spirulina is rich in protein, minerals, fats, carbohydrate & vitamins. It is grown on materials like waste water from potato processing plants, straw, molasses, animal manure & sewage. This also reduces environmental pollution. 

A micro-organism like Methylophilus methylotrophus produce 25 tonnes protein/day. 

TISSUE CULTURE

A technique of growing plant cells/tissues/organs in sterile culture medium under aseptic conditions. 

Totipotency: The ability to generate a whole plant from any cell/explant. 

Explant: Any part of a plant that is grown in a test tube under sterile nutrient media. 

Micropropagation: The method of producing thousands of plants in very short time through tissue culture. 

These plants will be genetically identical to original plant, i.e., they are somaclones. 

Tissue culture is also used for recovering healthy plants from diseased plants. The meristem (it will be free of virus) from infected plant is removed and grown it in vitro to obtain virus-free plants. 

Somatic hybridization: It is the fusion of protoplasts from two different varieties of plants to get hybrid protoplasts. It can be grown to form a new plant called somatic hybrids. E.g. Protoplast of tomato + protoplast of potato → pomato. 

Human health and disease

 HUMAN HEALTH AND DISEASES: 

CHAPTER AT A GLANCE

HUMAN INFECTIOUS DISEASES

Bacterial Diseases

Typhoid: 

• Pathogen: Salmonella typhi.
• Widal test: For confirmation of the disease. 
• Transmission: Food & water → small intestine. 
• Symptoms: High fever, weakness, stomach pain, constipation, headache & loss of appetite. Intestinal perforation. 

Pneumonia: 

• Pathogen: Streptococcus pneumoniae & Haemophilus influenzae
• Transmission: Inhaling droplets from patients, Sharing contaminated objects. 
• Symptoms: Respiratory problems, fever, chills, cough, headache. In severe cases, lips and finger nails turn gray to bluish colour.

Viral Diseases

Common cold: 

• Pathogen: Rhinovirus.
• Transmission: Inhaling droplets from cough or sneezes. Contaminated objects. 
• Symptoms: Nasal congestion & discharge, sore throat, cough, hoarseness, headache, tiredness.

Protozoan Diseases

Malaria: 

• Pathogen: Plasmodium sp. 
• Transmission: Female Anopheles mosquito. 
• Symptoms: Haemozoin toxin causes chill and high fever recurring every 3-4 days. 

Amoebiasis (Amoebic dysentery):

• Pathogen: Entamoeba histolytica
• Transmission: Houseflies transmit parasites from faeces to food & water. 
• Symptoms: Constipation, abdominal pain & cramps, stools with mucus and blood clots.

Helminth Diseases

Ascariasis:

• Pathogen: Ascaris 
  
• Transmission: Soil, water, vegetables, fruits etc. contaminated with faeces. 
• Symptoms: Internal bleeding, muscular pain, fever, anaemia, blockage of intestinal passage. 

Filariasis (Elephantiasis):

• Pathogen: Wuchereria (Filarial worms) 
• Transmission: Female Culex mosquito. 
• Symptoms: Chronic inflammation and deformity of limbs & genital organs. 

Fungal Diseases

Ringworm:

• Pathogen: Microsporum, Trichophyton & Epidermophyton 
• Transmission: From soil or towels, cloths, comb etc. 
• Symptoms: Dry, scaly lesions on skin, nails, scalp etc. Itching. 

Summary :

•  Transmitted through food and water — Typhoid,Amoebiasis,Ascariasis
•  Transmitted through air(airborne) —— pneumonia, common cold       
• Transmitted through  vector — Malaria(anopheles-female) ; filariasis(culex) ; dengue and  chikungunya (Aedes)

IMMUNE SYSTEM

LYMPHOID ORGANS 

The organs where origin/ maturation & proliferation of lymphocytes occur. 

2 types: Primary & Secondary. 

1. Primary lymphoid organs: Here, immature lymphocytes differentiate into antigen-sensitive lymphocytes. E.g. Bone marrow & thymus. 
2. Secondary lymphoid organs: The organs, to which matured lymphocytes migrate, interact with antigens and proliferate to effector cells. E.g. Spleen, lymph nodes, tonsils, Peyer’s patches, Mucosa associated lymphoid tissue (MALT) & appendix.

IMMUNITY 

2 types: Innate and Acquired. 

1. Innate immunity 

    Non-specific inborn immunity. 

    It includes 4 types of Barriers: 

• Physical barriers: E.g. Skin, Mucus. 
• Physiological barriers: E.g. gastric HCl, saliva, tear etc. 
• Cellular barriers: Phagocytes like WBC, macrophages etc. 
• Cytokine barriers: Virus infected cells → interferon → protect non-infected cells from viral infection. 

2. Acquired immunity 

    Pathogen specific immunity developed during lifetime. 

    First encounter of a pathogen → primary response in low intensity. 

    Second encounter → strong secondary (anamnestic) response. 

    These responses are carried out by 

• B-lymphocytes (B-cells): Produce antibodies. 
• T-lymphocytes (T-cells): Help B-cells to produce antibodies. 

Types of Acquired immune response 

1. Humoral immune response/ Antibody mediated immunity (AMI): It is mediated by antibodies. 
2. Cell-mediated response / cell-mediated immunity (CMI): It is mediated by T-lymphocytes. 

Structure of antibody 

Types of Acquired immunity 

• Active immunity: Here, antibodies are produced in host body. It is developed during natural infection by microbes or by injecting microbes during immunization. 
• Passive immunity: Here, readymade antibodies are given to the body. E.g. Foetus gets antibodies from mother through Placenta, infants gets antibodies (IgA) in colostrum. 

Types of Immunization 

1. Active Immunization (Vaccination) 

• Vaccine (inactivated pathogen or its antigenic proteins) is introduced into body for the development of antibodies. 
• E.g. Polio vaccine, Hepatitis B vaccine, DPT vaccine etc. 

2. Passive Immunization 

• It is the direct injection of pre-formed antibodies or antitoxin. It requires for quick immune response. 
• E.g. Immunization against Tetanus, snake venom etc. 

Autoimmunity

Due to genetic and other unknown reasons, the body attacks self-cells resulting in damage to the body. It is called auto-immune disease. E.g. Rheumatoid arthritis. 

Allergies

• Exaggerated response of the immune system to some antigens present in the environment. 
• Allergens: E.g. mites in dust, pollens, animal dander etc. 
• Symptoms: Sneezing, watery eyes, running nose, difficult breathing, wheezing etc. 
• Antibodies produced against the allergens are IgE type. 
• Asthma is a respiratory disease due to allergy. 
• Treatment: Drugs like anti-histamine, adrenaline and steroids quickly reduce the symptoms. 
• Modern-day life style & protected environment provided early in life results in low immunity and more sensitivity to allergens. So children in metro cities suffer from allergies and asthma.

AIDS (Acquired Immuno Deficiency Syndrome)

It is caused by HIV (Human Immunodeficiency Virus), a retrovirus having RNA genome. 

Transmission: Sexual contact with infected person, Transfusion of contaminated blood, Sharing of infected needles, From mother to child through placenta. 

Diagnosis: ELISA test (Enzyme-linked immuno-sorbent Assay). 

Treatment: Anti-retroviral drugs. 

Prevention: Educate people about AIDS, Make blood safe from HIV, Use disposable needles and syringes, Condoms, Control drug abuse. 

Replication of retrovirus: 

Life cycle of HIV: 

HIV enters body → To macrophages (acts as HIV factory) → RNA becomes viral DNA in presence of Reverse transcriptase → Viral DNA incorporates into host DNA→ produce virus particles → HIV enters helper T-cells (TH lymphocytes) → Replicates & produce progeny viruses → Attack other TH cells → TH cells decrease → Weaken immunity. 

CANCER

It is an abnormal and uncontrolled multiplication of cells to form tumour. 

Normal cells show contact inhibition (contact with other cells inhibits their uncontrolled growth). Cancer cells do not have this property. 

Types of Tumours: 

• Benign tumours: Confined to the place of its origin. Cause little damage. 
• Malignant tumours: Tumour cells (neoplastic cells) invade and damage surrounding tissues. Cells from tumours reach other sites via blood and form a new tumour. It is called metastasis. 

Causes of cancer (Carcinogens): 

• Physical agents: Radiations like X-rays, gamma rays, UV etc. 
• Chemical agents: Tobacco smoke, vinyl chloride, nicotine, etc. 
• Biological agents: Oncogenic viruses, c-onc (cellular oncogenes or proto oncogenes) etc. 

Cancer detection and diagnosis:

• Biopsy: Histopathological studies of suspected tissue. 
• Imaging techniques: Radiography, CT scan & MRI. 
• Use of antibodies against cancer-specific antigens. 
• Molecular biology technique: To detect cancer related genes. 

Treatment of cancer: 

• Radiotherapy
• Chemotherapy
• Immunotherapy
• Surgery.

DRUGS, SMOKING & ALCOHOL ABUSE

DRUGS 

1. Opioids: 

• E.g. morphine, heroin, brown sugar. 
• Morphine is extracted from latex of Papaver somniferum (poppy plant). It is a sedative & painkiller. Used in surgery. 
• Heroin (smack or diacetylmorphine) is obtained by acetylation of morphine. It is a depressant. 

2. Cannabinoids: 

• Obtained from Cannabis sativa (Hemp plant). 
• Includes marijuana, hashish, charas & ganja. 
• They affect cardiovascular system. 

3. Coca alkaloid or cocaine (coke or crack): 

• It is obtained from coca plant Erythroxylum coca. 
• It interferes with transport of neurotransmitter dopamine. 
• It stimulates CNS producing euphoria & increased energy. 

SMOKING

• Tobacco contains nicotine etc. 
• Smoking causes cancers of lung, urinary bladder and throat, bronchitis, emphysema, coronary heart disease, gastric ulcer etc. Tobacco chewing causes oral cancer. 
• Smoking increases CO content in blood and reduces oxyhaemoglobin. This causes O2 deficiency in the body. 

ADOLESCENCE & DRUG/ALCOHOL ABUSE 

Causes of drug/alcohol use in Adolescence 

• Curiosity and Experimentation. 
• Need for adventure and excitement. 
• To escape facing problems. 
• Stress from pressure to excel in academics or examination. 
• Television, movies, newspapers, internet etc. 
• Unstable or unsupportive family structures & peer pressure. 

Addiction: Psychological attachment with drugs & alcohol. 

Dependence: Body manifests unpleasant withdrawal syndrome if drugs/alcohol is abruptly discontinued. This results in anxiety, shakiness, nausea and sweating. 

Effects of Drug/alcohol abuse

• Reckless behaviour, vandalism and violence. 
• Coma and death. 
• Damage of nervous system and liver cirrhosis. 
• Causes mental and social distress to family and friends. 
• Social problems like stealing and spread of diseases. 
• Misuse of drugs by athletes. 

Warning signs of drug/alcohol abuse in Adolescence period

• Drop in academic performance and absence from school. 
• Lack of interest in personal hygiene. 
• Withdrawal and isolation. 
• Depression, fatigue, aggressive and rebellious behaviour. 
• Loss of interest in hobbies. 
• Deteriorating relationships with family and friends. 

Side effects of anabolic steroid abuse

In males:

• Acne, premature baldness 
• Mood swings & depression, increased aggressiveness. 
• Reduced testicles & decreased sperms. 
• Kidney & liver dysfunction. 
• Enlargement of Breast & prostate gland. 

In females:

• Masculinisation, excessive hair growth 
• Mood swings & depression, increased aggressiveness 
• Abnormal menstrual cycle, deepening of voice 
• Enlargement of clitoris 

Prevention and control 

• Avoid undue peer pressure. 
• Education and counselling. 
• Seeking help from parents and peers. 
• Looking for danger signs. 
• Seeking professional and medical help