XII Chap 12 Biotechnology Applications

Question 1

Some of the applications of biotechnology?

Answer 1

Therapeutics
Diagnostics
Genetically modified crops
Processed food
Bioremediation 
Waste treatment
Energy production

Question 2

3 critical areas of research in biotech?

Answer 2

1. Best catalyst - improved microbe or pure enzyme
2. Optimal conditions for a catalyst to act
3. Downstream processing technologies to purify protein/organic compound

Question 3

___________ succeeded in tripling the food supply

Answer 3

Green Revolution

Question 4

What are agrochemicals?

Answer 4

Fertilisers and pesticides

Question 5

What are GMO?

Answer 5

Genetically Modified Organisms

Bacteria, Fungi, Plants and Animals whose genes have been altered

Question 6

How has GM been useful?

Answer 6

1. Crops more tolerant to abiotic stresses
2. Reduced reliance on chemical pesticides
3. Reduced post harvest losses
4. Increased efficiency of mineral usage by plants (prevents early exhaustion of soil fertility)
5. Enhanced nutritional value of food

Question 7

What is Bt toxin?

What is a biopesticide?

Answer 7

toxin produced by bacterium Bacillus thuringiensis (Bt)

Plant in which gene has been cloned and to create resistance to insects

Question 8

Examples of bio-pesticides?

Answer 8

Bt cotton, Bt corn
rice
tomato, potato and soyabean

Question 9

How does Bt kill insects?

Answer 9

Protein crystals - toxic insecticidal protein.
Inactive in Bt, active in alkaline pH of the insect’s gut
Crystals solubilise => toxin binds to midgut epithelial cells => creates pores => cell swelling and lysis => death

Question 10

Bt toxins are insect group specific and so choice of gene depends on the crop + targeted pest. T or F?

Answer 10

True

Question 11

Which gene codes the toxin in Bt?

Answer 11

cryIAc named “cry”

Question 12

________ and _______ genes control the cotton ballworms

________ gene controls corn borer

Answer 12

cryIAc cryIIAb control the cotton ballworms

cryIAb controls corn borer

Question 13

_______ infects root of tobacco plants

Answer 13

nematode Meloidegyne incornitia

Question 14

How has the tobacco plant been made resistant to nematodes?

Answer 14

RNA interference (RNAi)

vector - Agrobacterium
gene produced both sense and anti-sense RNA (complementary) => double-stranded dsRNA => RNAi initiated => silenced nematode mRNA => death

Question 15

What is RNAi?

Answer 15

RNA interference is a cellular defense mechanism in all eukaryotic organisms

Question 16

How does RNAi work?

Answer 16

A specific mRNA gets silenced due to a complementary dsRNA molecule that binds to mRNA and prevents translation of mRNA

source of this complementary dsRNA can be viruses or transposons

Question 17

At present ________ recombinant therapeutics have been approved and _____ are used in India

Answer 17

30; 12

Question 18

Insulin used for diabetes was previously extracted from _______

Answer 18

pancreas of slaughtered cattle and pigs => some patients had allergies and other reactions

Question 19

What does insulin consist of ?

Answer 19

Two short polypeptide chains
chain A and chain B
linked - disulphide bridges

Question 20

How is insulin synthesised in mammals?

Answer 20

Pro-insulin needs to be processed before it becomes mature and functional;

contains an extra stretch of C-peptide => removed during maturation into insulin

Question 21

How is insulin produced now? Who pioneered it?

Answer 21

Eli Lilly - American company - 1983

two DNA sequences - one for chain A and one for chain B => introduced into plasmids of E coli to produce insulin chains => produced separately, extracted and combined with disulfide bonds => human insulin

Question 22

What does gene therapy involve?

Answer 22

correction of a genetic defect

delivery of a normal gene into individual/embryo

Question 23

First clinical gene therapy?

Answer 23

1990, 4-year-old girl, ADA deficiency, crucial enzyme for immune system

usually treated by bone marrow transplant or injection => both are not curative

lymphocytes from patient grown in culture => functional ADA cDNA introduced using retroviral vector => returned to patient.

Patient requires periodic infusion. However, if introduced in embryonic stages could be permanent

Question 24

What are some techniques for early diagnosis of a disease?

Answer 24

Recombinant DNA technology
Polymerase Chain Reaction (PCR)
Enzyme Linked Immuno-sorbent Assay (ELISA)

Question 25

Very low concentration of a bacteria or a virus can be detected by a PCR. T or F?

Answer 25

True

Question 26

______ is now routinely used to detect HIV in suspected AIDs patients and gene mutations in suspected cancer patients

Answer 26

PCR

Question 27

ELISA is based on what principle?

Answer 27

antigen-antibody interaction;

presence of antigen or antibodies => infection by pathogen

Question 28

What are transgenic animals?

Answer 28

DNA manipulated to possess/express an extra/foreign gene

Question 29

Over 95% of transgenic animals are ______

Answer 29

Mice

Question 30

Why are transgenic animals produced?

Answer 30

1. Study gene regulation and effect of genes i.e. normal physiology and development
2. Study disease (cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer’s)
3. Biological products - in 1997, the first transgenic cow produced human protein-enriched milk
4. Vaccine safety - test polio vaccines
5. Chemical safety testing - transgenic animals made that are more sensitive to toxic substances, exposed and studied

Question 31

______ can replace monkeys to test safety batches of vaccines

Answer 31

Transgenic mice

Question 32

________ varieties of rice in Inida

Answer 32

200,000

Question 33

What is biopiracy?

Answer 33

Use of bio-resources by multinational companies / other organisation without proper authorisation from countries and people concerned without compensatory payment

Question 34

Human insulin these days is made in _________

Answer 34

bacteria

Question 35

_______ are used as vectors in gene therapy

Answer 35

Viruses