NIOS Class 12 Biology Chapter 30 Solution – Biotechnology
NIOS Class 12 Biology Solution Chapter 30 Biotechnology . NIOS Class 12 Biology Chapter 30 Question Answers Download PDF. NIOS Class 12 Biology Notes.
Board |
NIOS |
Class |
12th (Higher Secondary) |
Subject |
Biology |
Topic |
Question Answer, Solution, Notes |
INTEXT 30.1
1.) Name three different kinds of microorganisms used in the manufacture of industrial products.
Ans: Fungi, yeast, bacteria
2.) Name three products obtained in industries by using microorganisms.
Ans: Alcohol , antibiotics , curd , cheese are the products obtained in industries by using microorganisms
3.) Name two alcohols produced through fermentation by yeast.
Ans: Ethanol , Butanol , Glycerol are alcohols produced through fermentation by yeast
4.) Name the two methods of inoculation of yeast in the medium.
Ans: A layer of yeast can be grown on top of nutritional medium. The term for this is support growth system. (b) Liquid media is used to suspend cells or mycelia. This is known as system of halted growth.
5.) Match the items given in columns A with those given in column B.
Ans:
Column A | Column B |
Bioreactor | (b) Fermentation tank |
2. Steaming under pressure | (c) Autoclave
|
3. Alcohol | (a) Butanol |
INTEXT 30.2
1.) Name the bacterium responsible for curdling of milk.
Ans: Lactobacillus is responsible for curdling of milk
2.) Who discovered antibiotic?
. Ans: By accident, Alexander Fleming discovered in 1928 that one bacterium can stop another from growing. The term “antibiotic” was first used in 1942 by Selman Waksman.
3.) What do you mean by second generation vaccines?
Ans: The “second generation vaccines” were created using recombinant DNA technology or genetic engineering,
4.) Which was the first vitamin to be produced by fermentation?
Ans: Vitamin C was the first vitamin to be produced by fermentation
5.) Which bacteria cause the production of biogas?
Ans: Biogas is made by the action of methanogenic bacteria on waste matter such as the faeces of humans or of cattle.
INTEXT 30.3
1.) Define genetic engineering.
Ans: The body’s genes or gene products can be replaced with identical copies of these genes, which are then kept in a gene library by scientists who also edit genetic material. The term for this is genetic engineering.
2.) What is a clone?
Ans: Clone is a group of genetically identical cells. Such cells are descendents
of a single cell
3.) What do you mean by the term recombinant DNA?
Ans: DNA from a plasmid or phage is known as r-DNA when a piece of foreign DNA is put into the latter.
4.) Where are plasmids found?
Ans: Plasmid are found in bacteria
5.) Why are restriction enzymes called “molecular scissors”?
Ans:They are enzymes, They either cut both strands at the same location or at different locations so that the two ends of the DNA strands hang out.
6.) Name the enzyme which joins DNA fragments.
Ans: Ligase joins DNA fragments
7.) What is a clonal vector?
Ans: a phage or plamid that may transfer foreign DNA and divide alongside the bacteria of which it is a member is clonal vector.
mean by transgenic organism?
Ans: Offspring with the transgenes are the tran
8.) What do you sgenic organisms. A better output can be achieved by introducing or enhancing desirable features in domestic animals and agricultural plants, particularly cattle by transgenic organism.
INTEXT 30.4
1.) Name any two proteins and , two enzymes obtained by recombinant DNA technology.
Ans: (i) Insulin, Growth hormone (ii) Proteases, Amylases
2.) How is recombinant DNA technology useful for pharmaceutical companies?
Ans: Antibiotics, vaccines and proteins of clinical value can be manufactured abundantly
3.) Name any two diseases for which bioengineered vaccines have already been developed.
Ans: Rabies and hepatitis B are developed.
INTEXT 30.5
1.) Define the term transgenic.
Ans: Producing animals with genes from another species is now conceivable thanks to genetic engineering. Transgene refers to the alien gene. Transgenic refers to the plant or animal containing the gene.
2.) Name the gall producing bacterium and the plasmid which can be conveniently used to produce transgenics.
Ans: Agrobacterium tumefaciens is the gall producing bacterium and T1 plasmid which can be conveniently used to produce transgenics.
3.) What is bioremediation?
Ans: Bacteria that have been genetically modified can remove environmental contaminants. Bioremediation is the term for this. Toxic contaminants are metabolically broken down by the converted bacteria into harmless chemicals.
INTEXT 30.6
1.) What causes the alteration of normal functioning of a gene ?
Ans: can occur when genes become defective due to mutations.
2.) Name two single gene disorders in human beings.
Ans: Haemophilia which causes defective blood clotting, chronic bleeding in joints. and Sickle cell anaemia
3.) State which cells have a low count in Severe Combined Immuno Deficiency (SCID).
Ans: B-cells and T-cells have a low count in Severe Combined Immuno Deficiency (SCID)
4.) Define gene therapy.
Ans: Gene Therapy thus may be defined as a technique in which a patient (sufferer) is given healthy genes to replace the defective ones inherited from the parents, or to enhance the action/reaction of the genes they already have.
INTEXT 30.7
1.) State the two approaches to human gene therapy.
Ans: Somatic and Germ line cells are the approaches to human gene therapy
2.) Name the three categories of somatic cell gene therapy.
Ans: In-vivo gene therapy, Ex-vivo gene therapy and Anti-sense gene therapy
3.) Name any two genetic diseases that can be treated by somatic gene therapy.
Ans: Somatic gene therapy refers to medical intervention used on bodily cells other than germ line cells. Thalassamia, certain types of cancer are the genetic diseases that can be treated by somatic gene therapy
4.) What is the direct delivery of the corrected gene into the tissue of the patient by the use of Adenovirus called
Ans: The direct delivery of the corrected gene into the tissue of the patient by the use of Adenovirus called In-vivo gene therapy .
TERMINAL EXERCISE
1.) Define biotechnology.
Ans: The definition of biotechnology is the industrial use of living things and biological processes including biochemistry, microbiology, and genetic engineering to create optimum application of microbes for human benefit
2). How are alcoholic beverages produced by fermentation? Mention the steps in the process.
Ans: (i) Fermenter or tank and the
nutrient medium are sterilised by
steam under pressure (autoclave).
(ii) The correct strain of yeast is selected.
(iii) The yeast is inoculated into the medium. Inoculation can be done in two ways:
(a) Yeast can be grown as a layer on the surface of nutrient medium. This
is called support growth system.
(b) Cells or mycelia are suspended in a liquid medium. This is called
suspended growth system.
(iv) Care is taken to maintain the right temperature, pH, oxygen and carbon-dioxide
concentration.
(v) The medium is stirred and left to ferment.
(vi) The sugar in the medium gets fermented by enzymes released by yeast.
(vii) The fermented product is taken out
3.) How can you make cheese and curd on a large scale?
Ans: Rennet tablets are used commercially for the production of cheese and yoghurt. The milk-curdling enzyme rennin is derived from the stomach of a calf
4.) What are antibiotics? Name five antibiotics and their sources.
Ans:Antibiotics are substances made by microorganisms like bacteria or fungus that stop the development of other microorganisms. Typically, antibiotics are tiny compounds with a molecular weight of fewer than 2000.Da.
Tetracyclin Streptomyces sp
Chlorotetracycline Streptomyces auriefaciens
Chloramphenicol S. venezuelae
Cycloheximide S. griseus
Streptomycin S. griseus
5.) How are different generations of vaccines produced?
Ans: “First generation vaccines” are those that are created utilizing disease-causing microorganisms that have been attenuated. The “second generation vaccines” were created using recombinant DNA technology or genetic engineering. 3rd generation is made by chemicals
6.) Describe the steps in the production of biogas and mention the precautions to be taken.
Ans: Biogas is made from organic waste including faecal matter. Cowdung or faeces have lignocellulose. The energy used as fuel comes from methane (CH4). Cowdung forms the primary source of biogas.
A few factors must be considered when producing biogas. These are listed below:
a.) No free oxygen should be present during fermentation, and the environment must be anaerobic.
b.) The pH in the fermenter should be 6.8 to 7.6 or close to neutral.
c.) Fermentation is to be carried out using methanogenic bacteria.
7.) Enumerate in a sequence the steps in recombinant DNA technology.
Ans: a.. A particular restriction enzyme is chosen.
b.) Cell culture is created with the necessary gene present in the cells.
c.). A restriction fragment is produced after the restriction enzyme cuts the DNA of the particular gene at both ends.
d.). The identical restriction enzyme removes a plasmid’s matching DNA sequence.
e.). Ligase connects the restriction segment where the sliced DNA was previously located. The plasmid transforms into a recombinant plasmid by adding a piece of foreign DNA. Plasmids are known as clonal vectors because they have the ability to transmit foreign DNA.
f.) The comptent cells are then combined with the recombinant plasmids to enter the bacterium.
g.) Microbes divide. Bacterial DNA and recombinant plasmids both reproduce simultaneously.
h.) In less than ten hours, a sizable population of bacteria with recombinant DNA can be produced (more than a million).
i.) DNA pieces placed into plasmids or bacteriophages (bacterial viruses) are then acquired and stored in a DNA library in many identical copies.
j.) The cloned DNA is contained in these bits.
8.) Describe the uses of genetic engineering.
Ans: Genetic engineering is used the body abnormality such as diabetis, A person suffering from Thalassemia lacks the gene for haemoglobin and can survive only through frequent blood transfusions , A person suffering from sickle cell anemia has an altered gene whose product makes the red blood corpuscles abnormal on exposure to oxygen because they contain faulty haemoglobin
9.) How can a transgenic animal be obtained?
Ans: Producing animals with genes from another species is now conceivable thanks to genetic engineering. Transgene refers to the alien gene. Transgenic refers to the animal harbouring the gene.
10.) Write a note on bioremediation.
Ans: Genetically engineered bacteria can clean up pollutants from the environment. This is called Bioremediation. The transformed bacteria metabolically breakdown toxic pollutants into harmless compounds.
11.) Define the term gene therapy. Under what condition does it become necessary to opt for such a therapy ?
Ans: Gene Therapy thus may be defined as a technique in which a patient (sufferer) is given healthy genes to replace the defective ones inherited from the parents, or to enhance the action/reaction of the genes they already have.
12.) What is meant by human somatic gene therapy? How does it differ from the germ line gene therapy? Which of the two have been successful so far and why?
Ans: A normal gene can be utilised to fix a genetic flaw once it has been cloned. Body cells are the intended targets for genetic transformation (normalising a faulty gene). This method aids in the correction of a genetic flaw that affects only a certain organ or tissue.
13.) Discuss in brief the different types of somatic gene therapy
Ans: Somatic gene therapy can be grouped under the broad categories of :
(a) Ex-vivo (outside the body) gene therapy: Cells extracted from the patient and genetically altered for use in this sort of therapy. When the same cells are transfused after the gene change
There is no immunological reaction (when transferred back).
(b) In-vivo (within the body) gene therapy
Direct delivery of a therapeutic gene into the cells of a patient’s specific tissue is a feature of this kind of gene therapy. The remedial gene is being transmitted by the use of the double-stranded DNA virus adenovirus.
(c) Antisense Therapy This treatment aims to stop or reduce the expression of a particular gene, hence reducing the amount of protein produced by the overproducing gene.