What traumatic event does Zitkala-Sa describe at the school?

The forcible cutting of her long hair

Why was the cutting of her hair so humiliating to Zitkala-Sa?

Among her people, shingled hair was worn by cowards and mourners

What are Bt crops and how do they resist pests?

Bt crops carry cry genes from Bacillus thuringiensis that produce a protein toxin (Bt toxin) becoming active in the alkaline gut of insects, killing the larvae.

Why is the Bt toxin harmless to the bacterium that produces it?

It exists as an inactive protoxin (crystal) in the bacterium and becomes active only in the alkaline pH of the insect gut.

How is human insulin produced using recombinant DNA technology?

The DNA sequences encoding the A and B peptide chains of insulin are introduced into E. coli, which produce the chains; they are then extracted and combined by disulphide bonds to form functional Humulin.

What is RNA interference and how is it used to protect plants?

RNAi silences a specific mRNA by complementary double-stranded RNA; transgenic plants producing dsRNA against nematode genes silence them, making the plant resistant.

What was the first disorder treated by gene therapy?

Adenosine deaminase (ADA) deficiency was the first disorder treated with gene therapy in 1990.

What is the advantage of using PCR in molecular diagnosis?

PCR amplifies even very low amounts of pathogen nucleic acid, enabling detection of infection before symptoms appear or before the pathogen reaches detectable levels.

What is Golden Rice and why was it developed?

Golden Rice is a biofortified, genetically engineered rice variety rich in pro-vitamin A (beta-carotene), developed to combat vitamin A deficiency.

Why are transgenic animals produced?

They are produced to study gene regulation and disease, to obtain biological products like proteins, to test the safety of vaccines and to test the toxicity of chemicals.

What is biopiracy and give an example?

Biopiracy is the unauthorised use of bio-resources or traditional knowledge by organisations without compensation; examples include patents related to Basmati rice, turmeric and neem.

What is the role of GEAC?

The Genetic Engineering Appraisal Committee makes decisions regarding the validity of GM research and the safety of introducing GM organisms for public services.

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Chapter 10: Biotechnology and its Applications — Class 12 Biology

Biology · 13 chapters

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Chapter 10: Biotechnology and its Applications

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Bt cotton is resistant to insects because it carries the:

Summary

This chapter surveys the applications of biotechnology in agriculture, medicine and other fields, along with the ethical issues they raise. In agriculture, genetically modified (GM) crops and transgenic plants are produced to improve tolerance to abiotic and biotic stresses, reduce pesticide use, increase nutritional value and reduce post-harvest losses. Examples include Bt cotton (carrying the cry genes of Bacillus thuringiensis for pest resistance), Bt brinjal, pest-resistant plants using RNA interference (RNAi) against nematodes (Meloidogyne incognita), and biofortified crops such as Golden Rice. In medicine, biotechnology enables the production of recombinant therapeutic proteins, exemplified by human insulin (Humulin) made by inserting the gene chains A and B into E. coli, gene therapy to correct genetic defects (the first case treated adenosine deaminase, ADA, deficiency), and molecular diagnostics using PCR, ELISA and recombinant DNA probes for early detection of pathogens and disorders. Transgenic animals are produced for research, biological products, vaccine safety testing and the study of disease. The chapter also addresses ethical issues and biopiracy, the unauthorised exploitation of bio-resources and traditional knowledge, and the role of the GEAC (Genetic Engineering Appraisal Committee) and patents, citing cases like the patenting of Basmati rice and the use of turmeric and neem.

Biotechnological applications in agricultureBt crops and pest-resistant plantsBiotechnological applications in medicineRecombinant insulin and gene therapyMolecular diagnosis and transgenic animalsEthical issues and biopiracy

Key terms

Transgenic organism

An organism whose genome has been altered by the introduction of one or more foreign genes.

Bt crop

A crop carrying cry genes from Bacillus thuringiensis that produce insecticidal toxins, such as Bt cotton.

Gene therapy

A collection of methods that correct a defective gene by introducing a normal gene into the patient.

RNA interference (RNAi)

A cellular defence mechanism that silences specific mRNA, used to develop pest-resistant plants.

Biopiracy

The exploitation of bio-resources and traditional knowledge of a country without proper authorisation or compensation.

Molecular diagnosis

Early and accurate disease detection using techniques such as PCR, ELISA and recombinant DNA probes.

Important questions

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Transgenic organism

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An organism whose genome has been altered by the introduction of one or more foreign genes.

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Practice quiz · Biotechnology and its Applications

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Biotechnology and its Applications

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