Cell Biology and Biotechnology Science Notes
Important Points :
- The structural and functional unit of the body is called a cell.
- Tissue is a group of cells that performs a similar and definite function. E.g. The muscular tissues in the body perform contraction and extensions thereby helping in locomotion.
- The conducting tissues of the plants like xylem and phloem transport the water and food respectively.
- The technique of tissue culture and genetic engineering has been studied last year. Tissue culture is ‘Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’.
- Genetic engineering and its use has also been studied under, ‘Introduction to biotechnology’.
- Various step-wise processes are done while performing the tissue culture. .
- These processes are primary treatment, reproduction/cell division/multiplication, shooting, or rooting, primary hardening, secondary hardening, etc.
Assign names in the figure given below:
→ Tissue Culture : Tissue culture is the technique in which ‘ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium is done. While performing experiments of tissue culture, a liquid, solid or gel-like medium prepared from agar, is used.
→ Such medium supplies nutrients and energy necessary for tissue culture technique. Different processes are to be done while performing tissue culture, viz. primary treatment, reproduction or multiplication, shooting and rooting, primary hardening, secondary hardening, etc. From the source plant, required tissues are taken out and all the processes are carried in an aseptic medium in laboratory.
Cell Biology/Cytology :
→ The study of structure, types and organelles of the cell, cell division and some other aspects together is known as cell biology or cytology. In the field of human health, there are revolutionary changes due to advances of cell biology.
→ Research Institutes for dedicated research in cell biology:
- National Centre for Cell Science (http://www.nccs.res.in) at Pune
- Instem (http://www.instem.res.in) at Bengaluru
Stem Cells :
Special types of cells present in the body of multicellular organisms that can give rise to cells of all other types are called stem cells:
- The zygote formed after fertilization of gametes contains mass of cells, which are similar cells. These are the stem cells. They can give rise to new organism.
- Stem cells can be used to produce new tissues in laboratory.
- Stem cells also play an important role in wound healing.
Differentiation of stem cells :
- Stem cells can form any type of cell during the further development.
- The formation of different types of tissues to perform specific and different functions is called differentiation of the stem cells.
- Once the new tissues are formed their capacity to differentiate is lost. Later they form cells which are similar to them.
stem cells found :
- In the umbilical cord present in the uterus of mother.
- In the blastocyst stage of embryonic development.
- In red bone marrow.
- In adipose connective tissue of adult human beings.
- In blood.
→ Stem cell preservation : Stem cell samples from umbilical cord blood, red bone marrow or blastocyst are taken and are kept in small, sterile vials, kept in liquid nitrogen at – 135°C to – 190°C. In this way, the stem cells can be preserved for a longer use.
→ Stem cell research :
- The revolutionary event that occurred in biotechnology is stem cell research.
- Stem cell research will cause the fundamental changes in the medical science.
- Stem cells are of two types depending upon the source, viz. embryonic stem cells and adult stem cells.
Embryonic stem cells :
→ Embryo is formed by divisions of zygote. These embryonic cells continuously divide by mitosis. These cells are stem cells.
→ But by 14th day of conception cell differentiation starts. This differentiation causes formation of 220 different types of cells, e.g. osteocytes (bone cells), hepatocytes (liver cells), and neurons, etc. from the stem cells.
→ Before the differentiation, the embryonic cells are called embryonic stem cells. These stem cells are primary, undifferentiated cells having ability to multiply. They are called parent cells of all types of human cells. The property to develop into different types of cells is called pleuripotency. This property is present in the stem cells.
→ Stem cells can be collected well before the beginning of differentiation and cultured with certain biochemical stimuli in laboratory. Based on the type of stimulus, stem cells transform themselves into desired type of cells, later the tissues and organs.
Adult stem cells : Stem cells taken from the adult body are called adult stem cells.
For adult stem cells following sources are used:
- Red bone marrow
- Adipose connective tissue
- Cord blood (after the birth)
Uses of Stem Cells:
|Cell therapy: Replacing the dead cells in patients of diabetes, myocardial infarction, Alzheimer’s disease, Parkinson’s disease, etc.
|In organ – failure such as kidney and liver,’ some tissues can be formed by stem cells and transplanted in a needy patient.
|The formation of blood cells in patients of anaemia, thalassemia, leukaemia, etc.
Organ transplantation :
→ If less efficient or completely functionless organ of the body is changed, the life of such patient can be saved. Kidney transplantation or skin transplantation can be done on the patients if there is suitable donor for the same.
→ Investigations about the factors such as blood group, diseases, disorders, age, etc. are done for donor and recipient. This matching is done before the transplantation.
→ Healthy donor should be available For kidney and skin, live donor can be taken but liver, heart, eyes can be donated posthumously, i.e. after death.
Organ and Body donation:
→ If the organs of deceased person are in good condition and functional, then they can be used for donation. Organ donations can save the life of other needy patients.
→ Due to progress in science, such donations are possible. The awareness about such posthumous donations should increase so that people can donate their bodies voluntarily.
→ Organ donation : By organ donation the critical patient’s life can be saved. Blind persons can again get the vision by getting a eye donation. Liver, kidneys, heart, heart valves, skin, etc. can be donated. Body donation : Body can be made available for research in medical studies, after body donation.
→ Organ transplantations are under the control of Transplantation Human Organs Act, 1994 and its further amendments of 2009, 2011 and 2014. These acts make the transplantation or donation process transparent and no one can be cheated.
→ The techniques of bringing about improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings is called biotechnology.
→ Biotechnology can be used in the fields of agriculture, horticulture, medical field, diagnosis of diseases etc. Biotechnology is used in the production of cash crops, improvement in varieties of cash crops, increase in abilities of plants to withstand environmental stresses, vaccine production, early diagnosis of congenital diseases, organ transplant, cancer research, production of artificial skin, cartilage, etc. in laboratories. It includes the techniques of genetic engineering and tissue culture.
→ Natural characters of some species may not have all useful features. Some of the characters may be deleterious. In order to avoid such varieties, GMO or Genetically Modified Organisms are created. For this purpose, the DNA is changed in the crops. The modified crops then possess required features.
→ Following changes have occurred in the crops due to biotechnology. The varieties that can withstand the changes in the environment can be created. E.g., constantly changing temperature, dry and wet droughts, climate change and some similar stressor-resistant varieties are produced through genetic engineering.
→ GM crops are resistant to insect pests, pathogens, chemical weedicides, etc., due to their changed genome. This reduces the use and the cost of chemical pesticides which are harmful.
→ Due to use of seeds of GM crops, there is improvement in nutritive value of crops. Therefore now, seeds of a better quality crops are being produced.
→ There is also a decrease in loss of crops. Subsequently there is increase in the cultivable land and agriculture. Some insect resistant crops such as Bt Cotton have been produced which is widely used in Maharashtra
Biotechnology and its Applications :
→ Biotechnology: The technology that brings about artificial genetic changes and hybridization in organisms for human welfare is called biotechnology.
- Cytology, biochemistry, molecular biology, and genetic engineering are different branches
of science that are included in biotechnology.
- In the field of agriculture and pharmacy major progress has been done due to biotechnology
- Improving the agricultural yield, production of high-class varieties of crops and suitable farm products through tissue culture are the aspects in which biotechnology is largely used.
- Pharmaceutical experiments to produce antibodies, vitamins, and hormones like insulin are taking support of biotechnological principles.
Inclusion of main areas in biotechnology :
- Microbiology : Using microbial abilities to form yoghurt from milk and alochol from molasses.
- Biochemistry : By increasing the productivity of the specific cell to manufacture antibiotics and vaccines, etc.
- Molecular biology : Use of bio-molecules like DNA and proteins in human welfare.
- Genetic engineering : By techniques of genetic manipulations, the plant and animal varieties and products of desired quality can be obtained. E.g. From genetically modified bacteria, human growth hormone ard insulin can be produced.
- Non-genetic biotechnology : By using entire cell or tissue, non-genetic biotechnology experiments are done. E.g. In tissue culture, production of hybrid seeds, etc. such methods are uset.
Benefits of Biotechnology:
- Increasing the per hectare yield of the crop land, irrespective of the limitations.
- By development of resistant varieties, the expenses on disease control become less.
- Fast fruit setting varieties are developed that increase the per annum yield.
- Varieties which can withstand changing environmental parameters such as variable temperature, water-stress, changing fertility of soil, etc. are created. These are stress resistant varieties.
Development of Biotechnology in India :
- Establishment of the National Biotechnology Board : 1982.
- Department of biotechnology under the ministry of science and technology : 1986.
Institutes under the control of this department are as follows:
- National Institute of Immunology
- National Facility for Animal Tissue and Cell Culture
- National Centre for Cell Science
- National Brain Research Centre
- Central Institute of Medicinal and Aromatic Plants.
- Facilities of higher education and research.
Commercial Applications of Biotechnology :
Animal Husbandry :
→ In animal husbandry, there are two main methods used :
- Artificial Insemination
- Embryo transfer
→ By these methods, the quantity and quality of animal products such as milk, meat and wool are both improved. Stronger animal varieties that can perform hard work have been developed.
- Biotechnology for human health management takes into consideration two important tasks, these are diagnosis and treatment of the diseases.
- Identifying the role of gene, in disease of a person. Diagnosis of diabetes and heart diseases can now be done even before the onset of symptoms.
- AIDS and dengue can be diagnosed within few minutes due to biotechnology. Treatment in such cases can be done at the earliest.
- Through biotechnology, medicines needed for the treatment can be manufactured. E.g. with the help of bacteria, human insulin can be made now.
- The human insulin gene is incorporated in bacterial genome for this purpose.
→ Various vaccines and antibiotics are also made in this way. On 5th July 1996, sheep ‘Dolly’ was the first animal clone born in Scotland. She was developed by a diploid nucleus of udder cells of Finn Dorset variety of sheep.
→ This nucleus was introduced into enucleated ovum (haploid nucleus was removed) of Scottish sheep. The ovum was then implanted in the uterus of Scottish sheep. Dolly showed characters of Finn Dorset sheep.
Industrial Products / White Biotechnology:
→ Manufacturing alcohol by using transgenic yeast on sugarcane molasses is one of the example of white biotechnology. Similarly many other industrial chemicals are produced through less expensive processes by substituting them with biotechnology.
Environment and Biotechnology:
- For treatment on sewage and solid wastes, microbial processes are used to speed up decomposition. If such organically rich sewage is released in natural water bodies, there is oxygen depletion in water.
- This is because the organic matter is oxidized with the help of dissolved oxygen in the water, Depletion in oxygen level adversely affects the aquatic life.
- Therefore, sewage is first oxidized by microbial techniques and then it is released
- Solid organic waste material is treated with microbes to produce compost on a large scale.
- Some new concepts in biotechnological methods are bio-remediation, biopesticides, biofertilizers, biosensors, etc.
→ In the process of bioremediation absorption or destruction of toxic chemicals and harmful pollutants is carried out with the help of plants and microorganisms. Phytoremediation is the method of bioremediation in which plants are used for this process.
Examples of phytoremediation:
|Cleaning the hydrocarbon and oil pollutants from soil and water.
|Fern Pteris vitata
|Absorbing the arsenic from the soil.
|Genetically modified variety of Indian mustard
|Absorbing selenium from soil.
|Absorbing uranium and arsenic.
|The bacterium, Deinococcus radiodurans
|Being a radiation resistant organism, it absorbs the radiations from radioactive debris. ,
|Grasses like alfalfa, clover and rye
|Used in phyto-remediation.
→ Food Biotechnology : Microorganisms are used for the manufacture of food items like bread, cheese, wine, beer, yoghurt, vinegar, soya sauce, etc.
DNA fingerprinting :
→ In every organism, the nucleotide sequence in the DNA molecule is unique. In human beings as a fingerprint is unique for every person, similarly DNA is also unique. Therefore, the technique to identify any person can be proved by his or her DNA.
- DNA fingerprinting technique is mainly used in investigations of forensic sciences.
- To establish identity of the criminal.
- To identify parents of any child in case of disputed parentage.
- In India DNA fingerprinting is done at “Centre for DNA fingerprinting and Diagnostics”, located at Hyderabad.
Cleaning of Oil Spillage in Oceans :
- Through the oil tankers or oil wells, there is oil spillage in the marine waters. This adversely affects the marine flora and fauna.
- By using oil-digesting and fast multiplying bacteria, such oil spills can be cleared in a lesser cost and without affecting the marine environment.
- Dr. Anand Mohan Chakravarti discovered the use of such bacteria.
Important Stages in Agricultural Development :
Green revolution :
- The improved methods for harvesting maximum yield from minimum land are collectively called green revolution.
- Large sector of Indian population has been saved from starvation due to green revolution.
- In green revolution, ‘methods of improvised dwarf varieties of wheat and rice, proper utilization of fertilizers and pesticides and appropriate water management have led to increased production of food grains.
- New varieties of various crops have been developed through different agricultural research institutes.
Various research institutes and laboratories :
→ Under ICAR, Indian Council of Agricultural Research, there are many research institutes located throughout India. These institutes perform active research regarding various cash crops, fishery and other agricultural related products.
- Indian Agricultural Research Institute (IARI), New Delhi
- National Citrus Research Institute, Nagpur and allied branches (ICAR-CCRI)
- Indian Institute of Sciences
- National Pomegranate Research Institute, Solapur.
White revolution :
→ The cooperative dairy movement that was undertaken with the help of biotechnology to produce abundant milk and dairy production, is called white revolution.
→ At Anand in the State of Gujarat, the cooperative movement was laid by Dr. Verghese Kurien. He took this movement to the greatest heights. AMUL (Anand Milk Union Limited) which was founded by him, has now become an international brand.
→ The self-sufficiency in dairy business was achieved due to white revolution. Many experiments done for quality control, newer dairy products and their preservation.
Blue revolution :
→ Blue revolution is production of various useful aquatic organisms by methods of aquaculture.
In East Asian region, fish species are raised in the farm ponds. This practice of rearing aquatic organisms is called aquaculture which is common in this region. Rearing fish is called pisciculture and that of marine organisms is mariculture.
→ Cultivation of the fishes and prawns (shrimps), marine organisms and sea weeds is also practised in India.
Government of India encourages the aquaculture activities. Government has launched the program “Nil-Kranti Mission-2016′ (NKM-16). Subsidies at 50% to 100% are offered in this case.
→ Aquaculture and mariculture can be carried along Indian coastline on a large scale. Fresh water fishes like rohu, catla and marine and brackish water prawns and lobster, etc. can be cultured on large scale.
|Improved water holding capacity of the soil. Soil conservation takes place.
|Decrease in fertility of soil due to excessive use.
|Due to humus formation, upper layer of the soil is formed.
|Toxic for soil bacteria, cattle, human.
|Essential elements (N, P, K) are easily available due to activities of earthworms and fungi.
|Contamination of the environment.
- Plants have natural immunity to fight against infections.
- To eradicate the pests, insecticides are used on plants. This use can be harmful for the environment.
Natural pest control measures such as insectivorous frogs and birds keep the pest population under control.
- But in an attempt to increase the yield, man excessively uses the pesticides and insecticides.
- These are toxic to all resident organisms.
- They also show biomagnification, in which the concentration of the insecticide goes on increasing according to the food chain.
- The insecticides like DDT, malathion, chloropyriphos also contaminate water and soil.
→ Organic farming:
- When the chemical fertilizers and pesticides are not used, only local, sturdy varieties are cultivated, and a natural balance is maintained, then such type of farming is called organic farming.
- Organic farming and organic products are in demand these days.
The use of chemical fertilizers and pesticides cause many environmental problems due to pollution.
- The soil fertility is decreased, the insect-pests become resistant and cause more damage.
- Organic farming can help to save the environment from such effects.
→ Apiculture :
- Apiculture is rearing of honey bees to obtain products such as honey and wax. In such practice, artificial hives are placed.
- By such practice, the honey can be extracted without causing any harm to the honey bees or their hives.
→ Cultivation of Medicinal Plants :
- In Ayurveda, different medicines are traditionally obtained from plants.
- The rich biodiversity of India was conducive in gathering such medicinal herbs from forests.
- Now due to deforestation, the medicinal plants and herbs are becoming rare. Hence their cultivation is to be done.
→ Fruit Processing:
- Fruit processing can form following products : Chocolates, juices, jams and jellies. Since ‘fruits are perishable agro-produce, processing is a must. .
- Different methods of fruit processing are keeping in cold storage, drying, salting, air tight packing, preparing jams (muramba), condensing, etc.