NCERT Solutions Class 12 Biology Chapter 12 Biotechnology and its Applications with answers available in Pdf for free download. The NCERT Solutions for Class 12 Biology with answers have been prepared as per the latest syllabus, NCERT books and examination pattern suggested in Standard 12 by CBSE, NCERT and KVS. Solutions to questions given in NCERT book for Class 12 Biology are an important part of exams for Grade 12 Biology and if practiced properly can help you to get higher marks. Refer to more Chapter-wise Solutions for NCERT Class 12 Biology and also download more latest study material for all subjects
Chapter 12 Biotechnology and its Applications Class 12 NCERT Solutions
Class 12 Biology students should refer to the following NCERT questions with answers for Chapter 12 Biotechnology and its Applications in standard 12. These NCERT Solutions with answers for Grade 12 Biology will come in exams and help you to score good marks
Chapter 12 Biotechnology and its Applications NCERT Solutions Class 12
Class 12 Biology
Chapter 12 Biotechnology and its Applications
Question 1: Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because −
(a) bacteria are resistant to the toxin
(b) toxin is immature:
(c) toxin is inactive:
(d) bacteria encloses toxin in a special sac.
Answer toxin is inactive: In bacteria, the toxin is present in an inactive form, called prototoxin, which gets converted into active form when it enters the body of an insect.
Question 2: What are transgenic bacteria? Illustrate using any one example.
Answer Transgenic bacteria contain foreign gene that is intentionally introduced into its genome. They are manipulated to express the desirable gene for the production of various commercially important products. An example of transgenic bacteria is E.coli. In the plasmid of E.coli, the two DNA sequences corresponding to A and B chain of human insulin are inserted, so as to produce the respective human insulin chains. Hence, after the insertion of insulin gene into the bacterium, it becomes transgenic and starts producing chains of human insulin. Later on, these chains are extracted from E.coli and combined to form human insulin.
Question 3: Compare and contrast the advantages and disadvantages of production of genetically modified crops.
Answer The production of genetically modified (GM) or transgenic plants has several advantages.
(i) Most of the GM crops have been developed for pest resistance, which increases the crop productivity and therefore, reduces the reliance on chemical pesticides.
(ii) Many varieties of GM food crops have been developed, which have enhanced nutritional quality. For example, golden rice is a transgenic variety in rice, which is rich in vitamin A.
(iii) These plants prevent the loss of fertility of soil by increasing the efficiency of mineral usage.
(iv) They are highly tolerant to unfavourable abiotic conditions.
(v) The use of GM crops decreases the post harvesting loss of crops. However, there are certain controversies regarding the use of genetically modified crops around the world. The use of these crops can affect the native biodiversity in an area. For example, the use of Bt toxin to decrease the amount of pesticide is posing a threat for beneficial insect pollinators such as honey bee. If the gene expressed for Bt toxin gets expressed in the pollen, then the honey bee might be affected. As a result, the process of pollination by honey bees would be affected. Also, genetically modified crops are affecting human health. They supply allergens and certain antibiotic resistance markers in the body. Also, they can cause genetic pollution in the wild relatives of the crop plants. Hence, it is affecting our natural environment.
Question 4: What are Cry proteins? Name an organism that produces it. How has man exploited this protein to his benefit?
Answer Cry proteins are encoded by cry genes. These proteins are toxins, which are produced by Bacillus thuringiensis bacteria. This bacterium contains these proteins in their inactive from. When the inactive toxin protein is ingested by the insect, it gets activated by the alkaline pH of the gut. This results in the lysis of epithelial cell and eventually the death of the insect. Therefore, man has exploited this protein to develop certain transgenic crops with insect resistance such as Bt cotton, Bt corn, etc.
Please click the link below to download NCERT Solutions Class 12 Biology Chapter 12 Biotechnology and its Applications.
Click for more Biology Study Material ›
|NCERT Solutions Class 12 Biology Chapter 1 Reproduction in Organisms|
|NCERT Solutions Class 12 Biology Chapter 2 Sexual Reproduction in Flowering Plants|
|NCERT Solutions Class 12 Biology Chapter 3 Human Reproduction|
|NCERT Solutions Class 12 Biology Chapter 4 Reproductive Health|
|NCERT Solutions Class 12 Biology Chapter 5 Principles of Inheritance and Variation|
|NCERT Solutions Class 12 Biology Chapter 6 Molecular Basis of Inheritance|
|NCERT Solutions Class 12 Biology Chapter 7 Evolution|
|NCERT Solutions Class 12 Biology Chapter 8 Human Health and Disease|
|NCERT Solutions Class 12 Biology Chapter 9 Strategies for Enhancement in Food Production|
|NCERT Solutions Class 12 Biology Chapter 10 Microbes in Human Welfare|
|NCERT Solutions Class 12 Biology Chapter 11 Biotechnology Principles And Processes|
|NCERT Solutions Class 12 Biology Chapter 12 Biotechnology and its Applications|
|NCERT Solutions Class 12 Biology Chapter 13 Organisms and Populations|
|NCERT Solutions Class 12 Biology Chapter 14 Ecosystem|
|NCERT Solutions Class 12 Biology Chapter 15 Biodiversity and Conservation|
|NCERT Solutions Class 12 Biology Chapter 16 Environmental Issues|