Sign Up

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.

Have an account?

Sign In

Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.

Don't have account,

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Have an account?

You must login to ask a question.

Need An Account,

You must login to add post.

Need An Account,

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

Search
Ask A Question
Home/ Education/ Exam/ NEET/ Biology/NEET 2025 MCQ with Answer Explanation : “Molecular Basis of Inheritance”.

love-insta : Question and Answer Sharing Platform. Latest Articles

On: October 4, 2024 Posted in Biology, Education, Exam, NEET Comments: 0 Views: 163

NEET 2025 MCQ with Answer Explanation : “Molecular Basis of Inheritance”.

  1. What is the role of telomerase in DNA replication?
    a) It adds nucleotides to the ends of chromosomes to prevent shortening
    b) It synthesizes RNA primers
    c) It unwinds the DNA double helix
    d) It repairs mismatched nucleotides

Answer: a) It adds nucleotides to the ends of chromosomes to prevent shortening

Explanation: Telomerase adds repetitive nucleotide sequences (telomeres) to the ends of eukaryotic chromosomes, protecting them from degradation during replication.

  1. Which of the following is true about the lac operon in E. coli?
    a) It is an example of a repressible operon
    b) It is activated when lactose is absent
    c) It is regulated by the repressor protein binding to the operator
    d) It controls the synthesis of tryptophan

Answer: c) It is regulated by the repressor protein binding to the operator

Explanation: The lac operon in E. coli is an inducible operon. When lactose is absent, the repressor binds to the operator, blocking transcription. When lactose is present, it binds to the repressor, preventing it from binding to the operator and allowing transcription.

  1. Which of the following is an example of a point mutation?
    a) Deletion of three nucleotides
    b) Duplication of a gene segment
    c) Substitution of one base pair
    d) Insertion of a large sequence

Answer: c) Substitution of one base pair

Explanation: A point mutation is a change in a single base pair, such as substitution, where one nucleotide is replaced by another. This may result in a silent, missense, or nonsense mutation.

  1. In prokaryotes, which of the following helps in the termination of transcription?
    a) Helicase
    b) rho protein
    c) DNA polymerase
    d) Telomerase

Answer: b) rho protein

Explanation: In prokaryotes, the rho protein is involved in the rho-dependent termination of transcription. It unwinds the RNA-DNA hybrid, causing the termination of RNA synthesis.

  1. Which of the following is involved in the splicing of introns from pre-mRNA?
    a) rRNA
    b) snRNA
    c) tRNA
    d) siRNA

Answer: b) snRNA

Explanation: Small nuclear RNA (snRNA) plays a crucial role in the splicing of pre-mRNA by recognizing splice sites and helping to remove introns from the transcript during the formation of mature mRNA.

  1. Which of the following statements about DNA replication is correct?
    a) DNA replication occurs in the 3′ to 5′ direction
    b) The leading strand is synthesized discontinuously
    c) DNA polymerase adds nucleotides to the 3′ end of the new strand
    d) The process does not require a primer

Answer: c) DNA polymerase adds nucleotides to the 3′ end of the new strand

Explanation: DNA polymerase can only add nucleotides to the free 3′ hydroxyl end of the growing DNA strand, which means replication always occurs in the 5′ to 3′ direction. The leading strand is synthesized continuously, while the lagging strand is synthesized in fragments (Okazaki fragments).

  1. What is the role of a codon in protein synthesis?
    a) It signals the end of transcription
    b) It directs the assembly of amino acids into a protein
    c) It binds to the anticodon on tRNA
    d) It unwinds the DNA double helix

Answer: b) It directs the assembly of amino acids into a protein

Explanation: A codon is a sequence of three nucleotides on mRNA that specifies a particular amino acid or signals the start or stop of protein synthesis during translation. The anticodon on tRNA pairs with the codon on mRNA to ensure the correct amino acid is added to the growing polypeptide chain.

  1. Which of the following is a stop codon in the genetic code?
    a) AUG
    b) UUU
    c) UAA
    d) UGG

Answer: c) UAA

Explanation: The three stop codons are UAA, UAG, and UGA, which signal the termination of protein synthesis. AUG is the start codon, and UUU codes for phenylalanine.

  1. The term “antiparallel” in the context of DNA structure refers to:
    a) The arrangement of the sugar-phosphate backbone
    b) The direction of the two DNA strands relative to each other
    c) The orientation of the nitrogenous bases
    d) The helical twist of the DNA strands

Answer: b) The direction of the two DNA strands relative to each other

Explanation: DNA strands run in opposite directions; one strand runs in the 5′ to 3′ direction, while the complementary strand runs in the 3′ to 5′ direction. This antiparallel arrangement is critical for the function and replication of DNA.

  1. In eukaryotes, the RNA that is synthesized directly from the DNA template is called:
    a) mRNA
    b) tRNA
    c) rRNA
    d) hnRNA

Answer: d) hnRNA

Previous article
Next article

Leave a comment