NEET Zoology — MCQ Practice Questions & Answers

Question 1

Which enzyme is used to cut DNA at specific recognition sequences in genetic engineering?

Accepted Answer

Correct answer: A. Restriction endonuclease — Restriction endonucleases recognize and cut DNA at specific palindromic sequences, producing sticky or blunt ends used in cloning.

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B. DNA ligase

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C. DNA polymerase

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D. Helicase

Question 2

What is the primary purpose of using plasmids in biotechnology?

Accepted Answer

Correct answer: B. As vectors for introducing foreign genes into host cells — Plasmids are small, circular DNA molecules used as vectors to carry and transfer foreign genes into host cells during genetic engineering.

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A. To store genetic information in prokaryotes

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C. To produce antibodies in animals

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D. To facilitate photosynthesis

Question 3

Which of the following is a transgenic organism?

Accepted Answer

Correct answer: A. Bt cotton — Bt cotton contains foreign genes from Bacillus thuringiensis, making it a true transgenic organism. Others are produced by conventional breeding or mutation.

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B. Hybrid wheat

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C. Polyploid watermelon

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D. Mutant rice produced by irradiation

Question 4

What does PCR stand for?

Accepted Answer

Correct answer: A. Polymerase Chain Reaction — PCR (Polymerase Chain Reaction) is a molecular technique for amplifying specific DNA sequences through repeated cycles of denaturation, annealing, and extension.

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B. Protein Coding Region

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C. Plasmid Cloning Replication

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D. Primary Cell Recognition

Question 5

In recombinant DNA technology, what is the function of DNA ligase?

Accepted Answer

Correct answer: B. To join DNA fragments by forming phosphodiester bonds — DNA ligase catalyzes the formation of phosphodiester bonds between adjacent nucleotides, joining DNA fragments together during cloning.

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A. To cut DNA at specific sites

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C. To denature double-stranded DNA

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D. To synthesize new DNA strands

Question 6

Which of the following techniques is used to create transgenic animals by introducing foreign DNA into the pronucleus of a fertilized egg?

Accepted Answer

Correct answer: A. Microinjection — Microinjection is the standard technique for creating transgenic animals by directly injecting DNA into the pronucleus of a fertilized egg, allowing integration into the genome.

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B. Electroporation

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C. Gene gun method

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D. Biolistic bombardment

Question 7

In CRISPR-Cas9 technology, what is the function of the guide RNA?

Accepted Answer

Correct answer: B. To direct Cas9 protein to the target DNA sequence — The guide RNA (gRNA) is complementary to the target DNA sequence and directs the Cas9 endonuclease protein to the exact location where the cut should be made.

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A. To cut the DNA at specific locations

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C. To synthesize new DNA strands

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D. To ligate DNA fragments together

Question 8

Which vector is preferred for delivering genes into plant cells for genetic modification?

Accepted Answer

Correct answer: C. Ti plasmid — The Ti (Tumor-inducing) plasmid from Agrobacterium tumefaciens is the natural vector for plant genetic modification, carrying T-DNA that integrates into the plant genome.

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A. Lambda phage

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B. Retrovirus

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D. Cosmid

NEET Zoology - MCQ Practice Questions