Bt protoxin crystals are fed to a caterpillar whose midgut is experimentally kept at an acidic pH. Using the known mode of action, what is the expected result?

Crystals stay unsolubilised, so active toxin does not form and midgut cells stay intact

Midgut cells start making the toxin themselves from the swallowed crystal protein

Crystals dissolve as usual, and pores cause the midgut cells to swell and burst

Acid activates the toxin faster, so the midgut cells are lysed much sooner

In India, the organisation that decides on the validity of GM research and the safety of introducing GM organisms for public services is the

Genetic Engineering Approval Committee

Indian Council of Medical Research

National Biodiversity Authority

Central Pollution Control Board

Given below are two statements: Statement I: A clone carrying a mutated gene appears on the photographic film because the probe cannot pair with it. Statement II: ELISA detects a pathogen by amplifying its nucleic acid through repeated cycles. Choose the correct answer.

Both Statement I and Statement II are incorrect

Statement I is incorrect but Statement II is correct

Both Statement I and Statement II are correct

Statement I is correct but Statement II is incorrect

Biotechnology and its Applications

19 NEET-UG practice questions on Biotechnology and its Applications, part of Zoology. The first 19 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
Bt protoxin crystals are fed to a caterpillar whose midgut is experimentally kept at an acidic pH. Using the known mode of action, what is the expected result?
1. AMidgut cells start making the toxin themselves from the swallowed crystal protein
2. BCrystals dissolve as usual, and pores cause the midgut cells to swell and burst
3. CCrystals stay unsolubilised, so active toxin does not form and midgut cells stay intact
4. DAcid activates the toxin faster, so the midgut cells are lysed much sooner
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Answer: C · Crystals stay unsolubilised, so active toxin does not form and midgut cells stay intact
The toxin stays inactive until the alkaline pH of the insect gut solubilises the crystals and converts it to the active form. Without alkalinity, this first step fails, so there is no binding to the epithelium, no pore formation and no lysis.
- A: Swallowed protein carries no gene, so the cells cannot make toxin from it.
- B: This ignores the need for alkaline pH to solubilise the crystals.
- D: This reverses the pH requirement for activation.
Remember this
Alkaline gut pH is the trigger for Bt toxin; crystals, activation, binding, pores, swelling and lysis follow in sequence.
Question 2 · Medium
Match List-I with List-II. List-I (transgenic animal work) A. Mice used to test polio vaccine B. Animals made more sensitive to toxic substances C. Models of cancer, cystic fibrosis and Alzheimer's disease D. Animals carrying the human gene for alpha-1-antitrypsin List-II (application) I. Study of disease II. Chemical safety testing III. Biological products IV. Vaccine safety
1. AA-I, B-II, C-IV, D-III
2. BA-II, B-IV, C-I, D-III
3. CA-IV, B-II, C-III, D-I
4. DA-IV, B-II, C-I, D-III
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Answer: D · A-IV, B-II, C-I, D-III
Testing polio vaccine in mice is vaccine safety, and using more sensitive animals is chemical safety testing. Disease models serve the study of disease, while human proteins made by animals are biological products.
- A: This swaps vaccine safety and disease study.
- B: This swaps vaccine safety and chemical safety.
- C: This swaps disease study and biological products.
Remember this
Five uses of transgenic animals: physiology and development, disease study, biological products, vaccine safety and chemical safety.
Question 3 · Easy
In India, the organisation that decides on the validity of GM research and the safety of introducing GM organisms for public services is the
1. AIndian Council of Medical Research
2. BGenetic Engineering Approval Committee
3. CNational Biodiversity Authority
4. DCentral Pollution Control Board
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Answer: B · Genetic Engineering Approval Committee
The Indian Government has set up GEAC for this purpose. It decides on the validity of GM research and on the safety of introducing GM organisms for public services.
- A: ICMR is a medical research council, not the GM approving body.
- C: This body is not the one named for GM organism approval.
- D: This board deals with pollution, not GM organism approval.
Remember this
GEAC judges GM research validity and safety; biopiracy concerns led to the Indian Patents Bill amendment.
Question 4 · Hard
Given below are two statements: Statement I: A clone carrying a mutated gene appears on the photographic film because the probe cannot pair with it. Statement II: ELISA detects a pathogen by amplifying its nucleic acid through repeated cycles. Choose the correct answer.
1. ABoth Statement I and Statement II are incorrect
2. BStatement I is incorrect but Statement II is correct
3. CBoth Statement I and Statement II are correct
4. DStatement I is correct but Statement II is incorrect
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Answer: A · Both Statement I and Statement II are incorrect
Statement I fails on logic: a probe that cannot pair with the mutated gene gives no signal, so that clone does not appear on the film. Statement II describes PCR; ELISA rests on antigen-antibody interaction.
- B: Statement II is false because amplification is PCR.
- C: Both statements contain an error, so neither is correct.
- D: Statement I is false because a mutated clone gives no signal.
Remember this
In probe screening, no pairing means no signal, so a mutated clone stays invisible on the film.
Question 5 · Medium
Read these statements on RNA interference. A. It takes place in all eukaryotic organisms as a method of cellular defence. B. It silences a gene by destroying its DNA in the nucleus. C. The complementary RNA may come from viruses with RNA genomes or from mobile genetic elements. D. Nematode-resistant tobacco was made to produce both sense and anti-sense RNA. Choose the correct option.
1. AB, C and D only
2. BA, C and D only
3. CA and C only
4. DA, B and D only
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Answer: B · A, C and D only
A, C and D are true. B is false because RNAi silences a specific mRNA: a complementary dsRNA binds it and prevents translation, while the DNA stays intact.
- A: This includes B and leaves out the true A.
- C: This leaves out D, which describes the transgenic tobacco correctly.
- D: This includes B, which wrongly places silencing at the DNA.
Remember this
RNAi silences mRNA, not DNA; the dsRNA can arise from RNA viruses, transposons or an introduced gene.
Question 6 · Medium
Given below are two statements: Statement I: If a functional ADA gene is introduced into cells at early embryonic stages, it could be a permanent cure. Statement II: Lymphocytes given in gene therapy are immortal, so an ADA patient needs no repeat infusion. Choose the correct answer.
1. ABoth Statement I and Statement II are incorrect
2. BBoth Statement I and Statement II are correct
3. CStatement I is incorrect but Statement II is correct
4. DStatement I is correct but Statement II is incorrect
Answer and explanation in LearnFree account
Question 7 · Easy
The first clinical gene therapy, given in 1990 to a 4-year-old girl, treated a deficiency of
1. AAdenosine deaminase
2. BBeta-galactosidase
3. CAlpha-1-antitrypsin
4. DAlpha-lactalbumin
Answer and explanation in LearnFree account
Question 8 · Medium
Match List-I with List-II. List-I (agent) A. RNA interference B. Rosie C. Alpha-1-antitrypsin D. cryIAb List-II (use) I. Control of corn borer II. Protection of tobacco roots against a nematode III. Treatment of emphysema IV. Human protein-enriched milk
1. AA-I, B-IV, C-III, D-II
2. BA-II, B-III, C-IV, D-I
3. CA-IV, B-II, C-III, D-I
4. DA-II, B-IV, C-III, D-I
Answer and explanation in LearnFree account
Question 9 · Easy
The insect-killing crystal protein of Bt crops comes from genes of
1. AMeloidogyne incognita
2. BBacillus thuringiensis
3. CThermus aquaticus
4. DAgrobacterium tumefaciens
Answer and explanation in LearnFree account
Question 10 · Medium
Which of the following are benefits of genetically modified plants? A. Greater tolerance to abiotic stresses such as cold and drought B. Higher post-harvest losses C. Greater reliance on chemical pesticides D. Increased efficiency of mineral use by plants Choose the correct option.
1. AA, B and D only
2. BA and D only
3. CA, C and D only
4. DB and C only
Answer and explanation in LearnFree account
Question 11 · Easy
Golden rice is a genetically modified rice enriched in
1. AVitamin B₁₂
2. BVitamin C
3. CIodine
4. DVitamin A
Answer and explanation in LearnFree account
Question 12 · Medium
Assertion A: Recombinant human insulin is preferred over insulin taken from slaughtered cattle and pigs. Reason R: Insulin from an animal source caused allergy or other reactions to the foreign protein in some patients. Choose the correct answer.
1. AA is correct but R is not correct
2. BBoth A and R are correct and R is the correct explanation of A
3. CA is not correct but R is correct
4. DBoth A and R are correct but R is not the correct explanation of A
Answer and explanation in LearnFree account
Question 13 · Hard
Match List-I with List-II. List-I (tool in molecular diagnosis) A. PCR B. ELISA C. Probe D. Autoradiography List-II (basis) I. Radioactively tagged single-stranded nucleic acid that pairs with its complement II. Exposure of a photographic film reveals where a tagged strand has bound III. Amplifies very small amounts of a pathogen's nucleic acid IV. Relies on antigen-antibody interaction
1. AA-III, B-I, C-IV, D-II
2. BA-III, B-IV, C-I, D-II
3. CA-IV, B-III, C-I, D-II
4. DA-III, B-IV, C-II, D-I
Answer and explanation in LearnFree account
Question 14 · Medium
Mature human insulin, as compared with its pro-hormone, lacks the
1. AA peptide
2. BB peptide
3. CDisulphide bridges
4. DC peptide
Answer and explanation in LearnFree account
Question 15 · Medium
An American company obtained a patent on a Basmati-derived rice in 1997, though the new variety came from Indian farmers' varieties. Using a country's bio-resources or traditional knowledge in this way without proper authorisation or compensation is called
1. ABioremediation
2. BBiomagnification
3. CBiopiracy
4. DBiofortification
Answer and explanation in LearnFree account
Question 16 · Hard
Transgenic tobacco that produces both sense and anti-sense RNA of nematode-specific genes resists Meloidogyne incognita. What is the basis of this protection?
1. AAnti-sense RNA converts the nematode DNA into a lethal mutant form
2. BThe two RNAs code for a new protein that blocks the nematode's feeding
3. CDouble-stranded RNA formed in the plant silences a specific nematode mRNA
4. DThe plant roots secrete Bt toxin that makes pores in the nematode gut
Answer and explanation in LearnFree account
Question 17 · Medium
Assertion A: Transgenic mice are used to test the safety of polio vaccine before use on humans. Reason R: Over 95 percent of all existing transgenic animals are mice. Choose the correct answer.
1. ABoth A and R are correct and R is the correct explanation of A
2. BA is not correct but R is correct
3. CBoth A and R are correct but R is not the correct explanation of A
4. DA is correct but R is not correct
Answer and explanation in LearnFree account
Question 18 · Easy
Milk of the transgenic cow Rosie, produced in 1997, was enriched in
1. AHuman insulin
2. BHuman alpha-1-antitrypsin
3. CHuman alpha-lactalbumin
4. DHuman interferon
Answer and explanation in LearnFree account
Question 19 · Medium
Given below are two statements: Statement I: The activated Bt toxin binds to the surface of plant leaf cells and creates pores in them. Statement II: The toxin in Bt cotton is coded by a gene named cry. Choose the correct answer.
1. AStatement I is correct but Statement II is incorrect
2. BBoth Statement I and Statement II are correct
3. CStatement I is incorrect but Statement II is correct
4. DBoth Statement I and Statement II are incorrect
Answer and explanation in LearnFree account

Biotechnology and its Applications

Bt protoxin crystals are fed to a caterpillar whose midgut is experimentally kept at an acidic pH. Using the known mode of action, what is the expected result?

In India, the organisation that decides on the validity of GM research and the safety of introducing GM organisms for public services is the

Given below are two statements: Statement I: A clone carrying a mutated gene appears on the photographic film because the probe cannot pair with it. Statement II: ELISA detects a pathogen by amplifying its nucleic acid through repeated cycles. Choose the correct answer.

Given below are two statements: Statement I: If a functional ADA gene is introduced into cells at early embryonic stages, it could be a permanent cure. Statement II: Lymphocytes given in gene therapy are immortal, so an ADA patient needs no repeat infusion. Choose the correct answer.

The first clinical gene therapy, given in 1990 to a 4-year-old girl, treated a deficiency of

Match List-I with List-II. List-I (agent) A. RNA interference B. Rosie C. Alpha-1-antitrypsin D. cryIAb List-II (use) I. Control of corn borer II. Protection of tobacco roots against a nematode III. Treatment of emphysema IV. Human protein-enriched milk

The insect-killing crystal protein of Bt crops comes from genes of

Which of the following are benefits of genetically modified plants? A. Greater tolerance to abiotic stresses such as cold and drought B. Higher post-harvest losses C. Greater reliance on chemical pesticides D. Increased efficiency of mineral use by plants Choose the correct option.

Golden rice is a genetically modified rice enriched in

Assertion A: Recombinant human insulin is preferred over insulin taken from slaughtered cattle and pigs. Reason R: Insulin from an animal source caused allergy or other reactions to the foreign protein in some patients. Choose the correct answer.

Mature human insulin, as compared with its pro-hormone, lacks the

An American company obtained a patent on a Basmati-derived rice in 1997, though the new variety came from Indian farmers' varieties. Using a country's bio-resources or traditional knowledge in this way without proper authorisation or compensation is called

Transgenic tobacco that produces both sense and anti-sense RNA of nematode-specific genes resists Meloidogyne incognita. What is the basis of this protection?

Assertion A: Transgenic mice are used to test the safety of polio vaccine before use on humans. Reason R: Over 95 percent of all existing transgenic animals are mice. Choose the correct answer.

Milk of the transgenic cow Rosie, produced in 1997, was enriched in

Given below are two statements: Statement I: The activated Bt toxin binds to the surface of plant leaf cells and creates pores in them. Statement II: The toxin in Bt cotton is coded by a gene named cry. Choose the correct answer.