Every Book Back multiple-choice question from Applications of Biotechnology (12th Standard Zoology, Samacheer Kalvi) — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
The first clinical gene therapy was done for the treatment of
- A. AIDS
- B. Cancer
- C. Cystic fibrosis
- D. SCIDCorrect
Explanation. SCID was the first disease treated with clinical gene therapy in 1990 by introducing a functional adenosine deaminase gene into the patient's cells.
Q2
Dolly, the sheep was obtained by a technique known as
- A. Cloning by gene transfer
- B. Cloning without the help of gametes
- C. Cloning by tissue culture of somatic cells
- D. Cloning by nuclear transferCorrect
Explanation. Dolly the sheep was cloned in 1997 using the somatic cell nuclear transfer technique, where a donor mammary gland cell nucleus was fused with an enucleated egg cell.
Q3
The genetic defect adenosine deaminase deficiency may be cured permanently by
- A. Enzyme replacement therapy
- B. Periodic infusion of genetically engineered lymphocytes having ADA cDNA
- C. Administering adenosine deaminase activators
- D. Introducing bone marrow cells producing ADA into embryo at an early stage of developmentCorrect
Explanation. Introducing functional ADA-producing bone marrow cells into the embryo at an early stage of development is a permanent cure because these cells can continuously divide and generate healthy immune cells.
Q4
How many amino acids are arranged in the two chains of Insulin?
- A. Chain A has 12 and Chain B has 13 amino acids
- B. Chain A has 21 and Chain B has 30 amino acidsCorrect
- C. Chain A has 20 and chain B has 30 amino acids
- D. Chain A has 12 and chain B has 20 amino acids
Explanation. Human insulin is composed of two polypeptide chains: Chain A has 21 amino acids, and Chain B has 30 amino acids, held together by disulfide bonds.
Q5
PCR proceeds in three distinct steps governed by temperature, they are in order of
- A. Denaturation, Annealing, SynthesisCorrect
- B. Synthesis, Annealing, Denaturation
- C. Annealing, Synthesis, Denaturation
- D. Denaturation, Synthesis, Annealing
Explanation. Polymerase chain reaction involves a cycle of three temperature-dependent steps: denaturation of DNA template, annealing of primers, and synthesis of new DNA strands by polymerase.
Q6
Which one of the following statements is true regarding DNA polymerase used in PCR?
- A. It is used to ligate introduced DNA in recipient cells
- B. It serves as a selectable marker
- C. It is isolated from a Virus
- D. It remains active at a high temperatureCorrect
Explanation. Taq DNA polymerase, isolated from the bacterium Thermus aquaticus, is used in PCR because it is extremely thermostable and remains active at the high temperatures required for DNA denaturation.
Q7
ELISA is mainly used for
- A. Detection of mutations
- B. Detection of pathogensCorrect
- C. Selecting animals having desired traits
- D. Selecting plants having desired traits
Explanation. ELISA stands for Enzyme-Linked Immunosorbent Assay. It is a highly sensitive biochemical technique used to detect specific antigens or antibodies, making it valuable for diagnosing pathogens.
Q8
Transgenic animals are those which have
- A. Foreign DNA in some of their cells
- B. Foreign DNA in all their cellsCorrect
- C. Foreign RNA in some of their cells
- D. Foreign RNA in all their cells
Explanation. Transgenic animals are genetically modified organisms that have foreign DNA integrated into the genomes of all their cells, allowing the transgene to be passed on to offspring.
Q9
Vaccines that use components of a pathogenic organism rather than the whole organism are called
- A. Subunit recombinant vaccinesCorrect
- B. attenuated recombinant vaccines
- C. DNA vaccines
- D. conventional vaccines
Explanation. Subunit recombinant vaccines use specific purified parts of a pathogen, such as proteins or peptides, to stimulate an immune response rather than using the entire virus or bacterium.
Q10
GEAC stands for
- A. Genome Engineering Action Committee
- B. Ground Environment Action Committee
- C. Genetic Engineering Approval CommitteeCorrect
- D. Genetic and Environment Approval Committee
Explanation. The Genetic Engineering Approval Committee is the Indian government body that regulates research, testing, and commercial release of genetically modified organisms and products to ensure safety.
About these Applications of Biotechnology questions
These are the Book Back multiple-choice questions for Applications of Biotechnology from the Tamil Nadu State Board (Samacheer Kalvi) 12th Standard Zoology syllabus. Each question shows the correct option and an original, step-by-step explanation so you understand the method, not just the answer. Use the answer key above to jump to any question, then take the practice test to check yourself under exam-like conditions.
Frequently asked questions
How many MCQs are there in Applications of Biotechnology?
This chapter has 10 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 12th Standard Zoology MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Applications of Biotechnology book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
