NIOS Class 12 Biology Chapter 24 Solution – Genetics and Society
NIOS Class 12 Biology Solution Chapter 24 Genetics and Society . NIOS Class 12 Biology Chapter 24 Question Answers Download PDF. NIOS Class 12 Biology Notes.
Board |
NIOS |
Class |
12th (Higher Secondary) |
Subject |
Biology |
Topic |
Question Answer, Solution, Notes |
INTEXT 24.1
1.) Name any two recent techniques in genetics.
Ans: Genetic engineering or recombinant DNA technology, gene cloning, DNA fingerprinting are the recent techniques in genetics.
2.) Define gene cloning
Ans: The term clone is a collective term for genetically identical individuals. The production of large quantities of identical genes is called gene cloning
3.) What is a gene bank ?
Ans: A gene bank is a collection of all the genes of any human or genes of any other organisms in various clones of bacteria.
INTEXT 24.2
1.) What is the popular term for recombinant DNA technology?
Ans: The the popular term for recombinant DNA technology is genetic engineering
2.) What is meant by DNA splicing?
Ans: Joining of two pieces of DNA belonging to different species is called DNA splicing
3.) What is a plasmid and why is it called a vector for genetic engineering?
Ans: A plasmid is a DNA molecule with a ring structure that is found in bacteria. It is not a piece of the bacterium’s chromosome. It functions as a vehicle for introducing foreign DNA into the host cell.
INTEXT 24.3
1.) Use the example of Bt crops to state importance of transgenic crops.
Ans: Transgenic crops are modified crops , transgenic crop like Bt crops reduce the need for use of insecticides which are toxic to humans and other animals.
2.) What is a cry protein?
Ans: Cry protein produced by Bt crop causes toxicity or poisoning when it enters the pest stomach killing the pest
3.) Exploiting a biological resource of another country without being authorised is called .
Biopiracy
4). When and why was the biopatent act adopted in India?
Ans: In 1970 , biopatent act adopted in India. It provides patents for invention to be used as food, medicine/ drugs, alloys, semiconductors etc
5.) What is the duration of a patent for pharmaceutical products in India?
Ans: The duration of a patent for pharmaceutical products in India
INTEXT 24.4
1.) Define genome.
Ans: The term “genome” refers to an organism’s whole set of genes. Since genes are paired,
2.) What is genomics?
Ans: The term “genome” refers to all of the genes found in a set of haploid (n) chromosomes.
3.) What is the use of genomics?
Ans: Genomics helps to identifying defective genes so that correction may be possible by gene therapy. It analysis the genome data, that is, finding out the functional nucleotide sequences (genes) in the DNA of an organism.
4.) Why should a genetic counsellor have good knowledge of genetics?
Ans: A genetic counsellor should have good knowledge of genetics because the counsellor has to advise regarding the possibility of genetic disorder in the next generation
5.) Expand the abbrenation PCR.
Ans: polymerase chain reaction (PCR), the polymerase chain reaction or PCR helps in making many copies of a small amount of DNA.
6.) Why is the tehnique DNA fingerprinting named so?
Ans: DNA fingerprinting is a method for identifying a specific person’s DNA. Heredity
It is utilised to conduct a scientific investigation into a crime and locate the true offender.
TERMINAL EXERCISE
1.) Name the three eras in the history of genetics.
(i) Early ideas
(ii)Modern Genetics
(iii) Molecular Genetics
2.) Define gene cloning. What is the usefulness of a gene bank?
Ans: The term clone is a collective term for genetically identical individuals. Gene cloning is the process of creating several copies of an identical gene.
In a gene bank, several clones of bacteria with the desired genes present in their DNA can be kept and stored at extremely low temperatures for later use. Thus, a collection of bacterial or bacteriophage (viral) clones makes up a gene bank, gene library, or DNA library. clones from a gene bank may be used for producing large quantities of certain enzymes, hormones and vaccines
3.) Give the various steps of recombinant DNA technology.
Ans: The following are the steps involved in producing rDNA:
(i) With the aid of restriction endonucleases, the required portion of DNA is removed from the cells. They identify particular nucleotide patterns in a DNA molecule and cleave (cut) those patterns.
(ii) A plasmid is a DNA molecule with a ring structure that is found in bacteria. It functions as a vehicle for introducing foreign DNA into the host cell.
(iii) The cleaved plasmids are then combined with the required DNA pieces. To replace their missing components, these plasmids take up foreign DNA fragments with the same base sequence. These develop into recombinant plastids with rDNA as the DNA.
(iv) Now, the bacteria that pick up the recombinant plasmids are exposed to or mixed with the recombinant plasmids. Along with the host bacteria, the r-plasmids in the bacterium multiply. rDNA-containing bacteria are quickly acquired as a clone.
4.) What are the benefits of genetic engineering?
Ans: Using genetic engineering or rDNA technology, essential substances including vaccines, hormones, vitamins, and antibodies can be produced. Genes responsible for producing these chemicals are inserted into bacteria, which are then cloned to create the desired substances. Examples of this include producing cheese-making enzymes and using recombinant bacteria to break down contaminants.
5.) What are transgenics? Give examples of a transgenic microbe, plant and animal.
Ans: Transgenics is another name for genetically modified organisms. Animals, plants, and microorganisms that have undergone genetic engineering may have one or more genes from a different species. Transgenic bacteria , tobacco plant and large fish, pigs etc.
6.) Define genomics
Ans: The term “genome” refers to all of the genes found in a set of haploid (n) chromosomes.
Genomics helps to identifying defective genes so that correction may be possible by gene therapy. It analysis the genome data, that is, finding out the functional nucleotide sequences (genes) in the DNA of an organism.
7.) Draw and explain a pedigree chart.
Ans: The pedigree analysis approach can reveal the pattern of inheritance of a specific characteristic (feature) in people. A pedigree is a diagrammatic representation of links that highlights a specific family feature. A pedigree chart is created by the genetic counsellor, who can subsequently provide advice based on it.
8.) What is genetic counselling and why is it important?
Ans: Genetic counselling refers to information provided about a genetic problem so that a couple can decide whether to have another child if their first kid has a genetic disorder. The genetic counsellor is well knowledgeable about human genetics and can estimate the likelihood that a family will carry a certain genetic abnormality.
9.) What is DNA fingerprinting? Justify that it is the foolproof tecnique for sorting out paternity issues.
Ans: DNA fingerprinting is a method for identifying a specific person’s DNA. Heredity
It is utilised to conduct a scientific investigation into a crime and locate the true offender.
DNA can be extracted from extremely little amounts of blood, semen, hair follicles, and tooth pulp and used to create a DNA fingerprint.This can be matched with the DNA of parents or child.
10.) List the steps of Polymerase chain reaction.
The steps in PCR are,
(i)Double helical DNA molecule is heated so that it breaks up into two strands
(ii)Primers are added and the DNA is cooled.
(iii)DNA polymerase is added and in its presence the two single strands acquire complementary strands and so two molecules of the DNA are formed.
11.) What are Bt crops? What are the benefits and fearns related to their use?
Ans: Bt crops are also referred to as transgenic crops because they are genetically altered. The reason Bt crops got their name is because the soil bacterium Bacillus thuringiensis (Bt) is responsible for introducing the transgenic or foreign gene into the crop.
Use of Bt crops reduces the need for spraying insecticides to kill insect pests.
Cry protein which is produce by Bt crop is a protein which is converted into a toxic substance by the enzyme present in the stomach of the pest, this toxic substance kills the pest.
12.) Write notes on
(i) Biopatent : An official document is a patent. This document gives the bearer permission to use or sell their idea. The Indian Patent Act of 1970 grants patents for inventions utilised in food, pharmaceuticals, metals, semiconductors, and other products.
(ii) Biopiracy : Patenting or using a biological resource belonging to another country without authorization or fair remuneration is known as “biopiracy.”
(iii) Necessity for a biosafety protocol: A Biosafety protocol was adopted by various nations, according to which the safety of adopting GM foods must first be established. According to EPA regulations, the Department of Biotechnology must be consulted before approving any research or use of a genetically modified organism and only after ensuring its safety for humans, other animals, and the environment.