Cell Biology and Biotechnology Class 10 Notes, Questions | SSC

This chapter begins with cytology and stem cells: where they are found, how they are preserved and how they are used in therapy and organ transplantation. It explains organ and body donation. It then describes biotechnology, its areas and benefits, its growth in India, and its commercial uses in crops, animal husbandry, human health, industry, environment, food and DNA fingerprinting. The last part covers the green, white and blue revolutions, organic farming, apiculture, medicinal plants and fruit processing.

Summary

Cell biology or cytology is the study of cell structure, types, organelles, cell division and other aspects of cells; the National Centre for Cell Science, Pune and inStem, Bengaluru carry out cell research in India. Stem cells are special cells that give rise to all other cell types in multicellular organisms and help in wound healing. In the early embryo all cells are alike stem cells; as development proceeds they differentiate into different tissues, after which tissue cells can at most form cells of the same kind.

Stem cells are found in the umbilical cord, in the blastocyst, and in adults in red bone marrow, adipose connective tissue and blood. Embryonic stem cells are the cells of the embryo before differentiation, which begins on the 14th day after conception; they can form all 220 types of human cells, a property called pluripotency. If collected on the 5th to 7th day and given suitable biochemical stimuli in the lab, they can form desired cells, tissues and organs. For preservation, samples from cord blood, bone marrow or blastocyst are kept in sterile vials in liquid nitrogen at \( -135^\circ C \) to \( -190^\circ C \).

Stem cells are used in regenerative therapy: cell therapy to replace dead cells in diabetes, myocardial infarction, Alzheimer's and Parkinson's disease, and to produce blood cells in anaemia, thalassemia and leukemia. They may also be used to grow organs like kidney and liver for transplantation. A person can donate one kidney and some skin while alive, while liver, heart and eyes can be donated only after death. Blood group, disease, age and other factors of donor and recipient must match. Organ and body donation saves lives and supports medical research, and is regulated by the Transplantation of Human Organs Act, 1994, amended in 2009, 2011 and 2014.

Biotechnology means bringing about artificial genetic changes and hybridization in organisms for human welfare; it combines cytology, biochemistry, molecular biology and genetic engineering. Its areas include using microbial abilities, cell productivity, biomolecules such as DNA and proteins, gene manipulation, and genetic and non-genetic techniques such as tissue culture and hybrid seeds. Its benefits are higher yield per hectare, lower disease-control costs through resistant varieties, fast fruit-setting varieties and stress-resistant varieties. India set up the National Biotechnology Board in 1982, which became the Department of Biotechnology in 1986.

In crops, biotechnology gives hybrid seeds and genetically modified crops. Bt cotton and Bt brinjal carry a gene from Bacillus thuringiensis that makes a toxin which kills the bollworm or pest by destroying its alimentary canal. Golden rice, developed in 2005, carries a gene for beta carotene and has 23 times more of it than normal rice. Herbicide-tolerant crops allow selective killing of weeds. Biofertilizers such as Rhizobium, Azotobacter, Nostoc, Anabaena and Azolla improve nitrogen fixation and phosphate solubilization. In animal husbandry, artificial insemination and embryo transfer improve milk, meat and wool.

In human health, biotechnology allows early diagnosis of diabetes and heart disease and quick tests for AIDS and dengue. Human insulin is now made by bacteria carrying the human insulin gene. Modern vaccines use pure antigen proteins made from pathogen genes, which are safer, more thermo-stable and longer lasting; transgenic potatoes are being developed as edible vaccines against Vibrio cholerae and E. coli. Biotechnology also gives insulin, somatotropin, clotting factors and interferon (made by transgenic E. coli), somatic cell gene therapy for disorders such as phenylketonuria, and cloning. Dolly the sheep was cloned in Scotland on 5 July 1996 using a nucleus from a Finn Dorset udder cell; therapeutic cloning produces stem cells for treatment.

White biotechnology produces industrial chemicals cheaply, such as alcohol from molasses using transgenic yeast. Microbial treatment of sewage before release protects dissolved oxygen in rivers. Bioremediation uses plants and microbes to absorb or destroy pollutants; with plants it is phytoremediation. Examples are Pseudomonas for oil, Pteris vittata for arsenic, GM Indian mustard for selenium, sunflower for uranium and arsenic, and Deinococcus radiodurans for radiation; Dr. Anand Mohan Chakravarti first suggested oil-digesting bacteria for oil spills. Bread, cheese, wine, yoghurt and vinegar are among the oldest biotechnology foods, and DNA fingerprinting, done at the Centre for DNA Fingerprinting and Diagnostics, Hyderabad, identifies criminals and establishes parentage.

The green revolution used improved dwarf wheat and rice, fertilizers, pesticides and water management to raise grain output; Dr. Norman Borlaug and Dr. M. S. Swaminathan contributed to it. The white revolution in dairy was led by Dr. Verghese Kurien through the cooperative movement at Anand, Gujarat. The blue revolution increases production of useful aquatic organisms, supported by the Nil-Kranti Mission 2016 with 50% to 100% subsidies. Organic farming bans chemical fertilizers and pesticides such as DDT, malathion and chloropyriphos, which bio-magnify in food chains. Bee boxes let honey be collected without destroying hives, medicinal plants like adulsa and neem are now cultivated, and fruit processing such as cold storage, drying, salting and air-tight packing makes perishable fruits available all year.

Mind map

How Dolly the sheep was cloned

Important definitions

Key points to remember

• Stem cells are present in the umbilical cord, blastocyst, red bone marrow, adipose tissue and blood.
• Cell differentiation starts from the 14th day of conception; human body has 220 cell types.
• Stem cells are stored in liquid nitrogen at \( -135^\circ C \) to \( -190^\circ C \).
• Stem cell research is the revolutionary event in biotechnology after cloning.
• Transplantation of Human Organs Act, 1994, amended in 2009, 2011 and 2014.
• National Biotechnology Board 1982; Department of Biotechnology 1986.
• Bt crops carry a gene from Bacillus thuringiensis.
• Golden rice (2005) has 23 times more beta carotene.
• Insulin for diabetes, somatotropin (human growth hormone; the textbook table prints 'somatostatin') for dwarfism, erythropoietin for anaemia, factor VIII for haemophilia, interleukin for cancer, interferon for viral infection.
• Dolly, the cloned sheep, was born on 5 July 1996 in Scotland.
• IISc developed transgenic tobacco that protects cattle from rinderpest.
• DNA fingerprinting research is done at CDFD, Hyderabad.
• Green revolution: Norman Borlaug and M. S. Swaminathan; white revolution: Verghese Kurien.
• Nil-Kranti Mission 2016 promotes pisciculture under the blue revolution.

Solved examples

Example 1. Complete the analogy: Insulin : Diabetes :: Interleukin : ____

Insulin is the biotechnology protein used for diabetes. From the textbook list, interleukin is used against cancer. Answer: Cancer.

Example 2. Complete the analogy: White revolution : Dairy :: Blue revolution : ____

White revolution increased milk production. Blue revolution is about producing useful aquatic organisms. Answer: Fishery (pisciculture).

Example 3. Correct the statement: Gene from Bacillus thuringiensis is introduced into soyabean.

The Bacillus thuringiensis gene was introduced into cotton (and brinjal) to make Bt cotton and Bt brinjal. Corrected: Gene from Bacillus thuringiensis is introduced into cotton.

Example 4. Correct the statement: Changes in genes of the cells are brought about in non-genetic technique.

Non-genetic biotechnology uses cells or tissues without changing genes, for example tissue culture and hybrid seeds. Corrected: Changes in genes of the cells are brought about in genetic technique.

Example 5. Explain how Bt cotton protects itself from bollworms.

1. A gene was isolated from the bacterium Bacillus thuringiensis. 2. It was integrated into the genome of cotton. 3. The plant now makes a toxin in its leaves and bolls. 4. When a bollworm feeds on them, the toxin destroys its alimentary canal. 5. The bollworm dies, so the crop is protected.

Important questions and answers

Q1. Fill in: Methods like artificial insemination and embryo transplant are mainly used for ____.

Animal husbandry.

Q2. Fill in: ____ is the revolutionary event in biotechnology after cloning.

Stem cell research.

Q3. Fill in: The disease related with the synthesis of insulin is ____.

Diabetes.

Q4. Fill in: Government of India encouraged ____ by launching NKM-16.

Pisciculture (blue revolution).

Q5. Match: Interferon, Factor VIII, Somatotropin (growth hormone), Interleukin.

Interferon: viral infection. Factor VIII: haemophilia. Somatotropin (growth hormone): dwarfism. Interleukin: cancer.

Q6. What are stem cells? Write their uses.

Stem cells are undifferentiated cells that can multiply and form all other cell types. Uses: cell therapy to replace dead cells in diabetes, myocardial infarction, Alzheimer's and Parkinson's disease; producing blood cells in anaemia, thalassemia and leukemia; and producing organs like kidney and liver for transplantation.

Q7. Explain the meaning of vaccination and how biotechnology made vaccines safer.

A vaccine is antigen-containing material given to gain immunity against a specific pathogen. Older vaccines used killed or partly killed pathogens, which could sometimes cause the disease. Biotechnology produces the antigen protein in the lab from the pathogen's gene, and only this pure antigen is injected. Such vaccines are safer, more thermo-stable and remain active longer, e.g. polio and hepatitis vaccines.

Q8. Why are some organs of the human body very valuable?

Organs like kidney, liver, heart and eyes may stop working due to ageing, accidents, infection or disorders, and the person's life may be in danger. Only a kidney and some skin can be donated while alive; liver, heart and eyes only after death. A donated organ can save a life or restore vision, so these organs are very valuable.

Q9. What is DNA fingerprinting? Give its uses.

Every person's DNA sequence is unique like fingerprints, so identity can be established from available DNA. It is used in forensic science to identify a criminal from any body part found at the crime scene and to establish the father of a child. Research is done at CDFD, Hyderabad.

Q10. What is bioremediation? Give examples.

Absorbing or destroying toxic chemicals and pollutants using plants and microbes; with plants it is phytoremediation. Examples: Pseudomonas cleans oil from soil and water, the fern Pteris vittata absorbs arsenic, GM Indian mustard absorbs selenium, sunflower absorbs uranium and arsenic, and GM Deinococcus radiodurans absorbs radiation from radioactive debris.

Q11. Why are farmers turning to organic farming?

Chemical fertilizers and pesticides reached the human body through food and water and harmed people and the environment; they reduce soil fertility, and pesticides like DDT, malathion and chloropyriphos bio-magnify in food chains. Organic farming completely bans chemical fertilizers and pesticides and uses local, sturdy varieties, thereby maintaining the natural balance.

Q12. Explain the importance of fruit processing.

Fruits are perishable. Processing by cold storage, drying, salting, air-tight packing, making murabba and evaporating lets them be used throughout the year and gives products such as juices, jams, jellies and chocolates.

Exam tips

• Memorise the six protein-disease pairs; they appear as match the pairs and analogies.
• Learn dates and names: 1982, 1986, 1994 Act, 5 July 1996 (Dolly), 2005 (golden rice), NKM-16.
• In stem cell answers mention both sources and uses.
• For revolutions, write the field and the person: green (Borlaug, Swaminathan), white (Kurien), blue (fishery).
• Keep bioremediation examples ready as plant or microbe with the pollutant it removes.

FAQs

Where are stem cells found in adults?

In red bone marrow, adipose connective tissue and blood. Cord blood collected at birth is another source.

What is golden rice?

A rice variety developed in 2005 with a gene for beta carotene (vitamin A precursor); it has 23 times more beta carotene than normal rice.

Which organs can be donated while alive?

One kidney and skin from certain parts of the body. Liver, heart and eyes can be donated only after death.

Who led the white revolution in India?

Dr. Verghese Kurien, through the cooperative dairy movement of Anand, Gujarat.

These notes were prepared with AI help from the Balbharati Science and Technology Part 2 textbook (2026-27) and checked against it.