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DNA Replication MCQs
DNA replication is a fundamental biological process essential for the growth and reproduction of all living organisms. It involves the duplication of a DNA molecule, resulting in two identical copies, which is crucial for cell division and inheritance. Understanding DNA replication is particularly important for students preparing for the NEET (National Eligibility cum Entrance Test) as it forms a significant part of the NEET biology syllabus.
To aid in the preparation, various MCQs on DNA Replication for NEET are available, which test knowledge on key concepts such as the mechanisms of replication, the roles of enzymes involved, and the differences between leading and lagging strands. These DNA Replication MCQs with answers provide a valuable resource for students to practice and reinforce their understanding of the topic.
In this context, students can explore numerous DNA Replication MCQs questions for NEET that cover critical aspects of the process, ensuring a comprehensive grasp of the subject. Engaging with these MCQs on DNA Replication not only helps in identifying strengths and weaknesses in the subject matter but also prepares students for the types of questions they may encounter in the NEET examination.
DNA Replication MCQs with Answers
Here are 30 multiple-choice questions MCQs on DNA replication, complete with answers. Each question is bolded, and the answer options are listed in bullet points for clarity.
What is the primary enzyme responsible for synthesizing new DNA strands during replication?
- A) RNA polymerase
- B) DNA ligase
- C) DNA polymerase
- D) Helicase
Answer: C) DNA polymerase
During DNA replication, the strands of the double helix are separated by which enzyme?
- A) Topoisomerase
- B) DNA ligase
- C) Helicase
- D) Primase
Answer: C) Helicase
What is the function of primase in DNA replication?
- A) To synthesize RNA primers
- B) To unwind the DNA helix
- C) To join Okazaki fragments
- D) To remove RNA primers
Answer: A) To synthesize RNA primers
Which strand of DNA is synthesized continuously during replication?
- A) Lagging strand
- B) Leading strand
- C) Okazaki strand
- D) Antisense strand
Answer: B) Leading strand
What are Okazaki fragments?
- A) Short segments of RNA
- B) Short segments of DNA synthesized on the lagging strand
- C) Long continuous strands of DNA
- D) DNA segments that are removed during replication
Answer: B) Short segments of DNA synthesized on the lagging strand
Which of the following is NOT a function of DNA polymerase?
- A) Synthesizing new DNA
- B) Proofreading DNA
- C) Unwinding the DNA helix
- D) Adding nucleotides to the growing DNA strand
Answer: C) Unwinding the DNA helix
What is the role of DNA ligase in DNA replication?
- A) To synthesize RNA primers
- B) To join Okazaki fragments
- C) To unwind the DNA strands
- D) To add nucleotides
Answer: B) To join Okazaki fragments
Which base pairs with adenine during DNA replication?
- A) Cytosine
- B) Thymine
- C) Guanine
- D) Uracil
Answer: B) Thymine
What is the significance of the replication fork?
- A) It is where DNA is synthesized.
- B) It is the point where DNA strands are separated.
- C) It is where RNA is synthesized.
- D) It is the site of protein synthesis.
Answer: B) It is the point where DNA strands are separated.
Which of the following statements about DNA replication is true?
- A) It occurs in a bidirectional manner.
- B) It is a unidirectional process.
- C) It only occurs during cell division.
- D) It requires no enzymes.
Answer: A) It occurs in a bidirectional manner.
What is the first step in the process of DNA replication?
- A) Synthesis of new DNA strands
- B) Unwinding of the DNA double helix
- C) Formation of Okazaki fragments
- D) Ligation of DNA fragments
Answer: B) Unwinding of the DNA double helix
Which enzyme removes RNA primers during DNA replication?
- A) DNA polymerase I
- B) DNA polymerase III
- C) Primase
- D) Ligase
Answer: A) DNA polymerase I
What is the role of topoisomerase in DNA replication?
- A) To synthesize RNA primers
- B) To unwind the DNA helix
- C) To relieve tension in the DNA helix
- D) To join Okazaki fragments
Answer: C) To relieve tension in the DNA helix
Which of the following is a characteristic of the lagging strand?
- A) It is synthesized continuously.
- B) It is synthesized in short fragments.
- C) It does not require RNA primers.
- D) It is synthesized in the same direction as the replication fork.
Answer: B) It is synthesized in short fragments.
In which phase of the cell cycle does DNA replication occur?
- A) G1 phase
- B) S phase
- C) G2 phase
- D) M phase
Answer: B) S phase
What is the function of single-strand binding proteins (SSBPs) during DNA replication?
- A) To unwind the DNA
- B) To stabilize unwound DNA strands
- C) To synthesize RNA primers
- D) To join Okazaki fragments
Answer: B) To stabilize unwound DNA strands
Which of the following is true about the direction of DNA synthesis?
- A) DNA is synthesized in the 3′ to 5′ direction.
- B) DNA is synthesized in the 5′ to 3′ direction.
- C) DNA can be synthesized in both directions simultaneously.
- D) DNA synthesis does not have a specific direction.
Answer: B) DNA is synthesized in the 5′ to 3′ direction.
What type of bond connects the nucleotides in a DNA strand?
- A) Hydrogen bonds
- B) Ionic bonds
- C) Covalent bonds
- D) Peptide bonds
Answer: C) Covalent bonds
Which of the following is a key difference between prokaryotic and eukaryotic DNA replication?
- A) Prokaryotic DNA is circular; eukaryotic DNA is linear.
- B) Eukaryotic DNA has a single origin of replication; prokaryotic DNA has multiple.
- C) Prokaryotic replication is slower than eukaryotic replication.
- D) Eukaryotic cells do not use DNA polymerase.
Answer: A) Prokaryotic DNA is circular; eukaryotic DNA is linear.
What is the role of telomerase in DNA replication?
- A) To synthesize RNA primers
- B) To extend the telomeres of chromosomes
- C) To join Okazaki fragments
- D) To remove RNA primers
Answer: B) To extend the telomeres of chromosomes
Which of the following is NOT a component of DNA?
- A) Phosphate group
- B) Ribose sugar
- C) Nitrogenous base
- D) Deoxyribose sugar
Answer: B) Ribose sugar
What is the purpose of the proofreading function of DNA polymerase?
- A) To synthesize RNA primers
- B) To correct errors in DNA synthesis
- C) To unwind the DNA strands
- D) To join Okazaki fragments
Answer: B) To correct errors in DNA synthesis
What is the end product of DNA replication?
- A) One double-stranded DNA molecule
- B) Two identical double-stranded DNA molecules
- C) Two single-stranded DNA molecules
- D) One single-stranded DNA molecule
Answer: B) Two identical double-stranded DNA molecules
Which enzyme is responsible for synthesizing the leading strand during DNA replication?
- A) DNA polymerase I
- B) DNA polymerase III
- C) Primase
- D) Ligase
Answer: B) DNA polymerase III
What is the role of the replication bubble in DNA replication?
- A) To synthesize RNA primers
- B) To provide space for DNA synthesis
- C) To stabilize the DNA strands
- D) To join Okazaki fragments
Answer: B) To provide space for DNA synthesis
Which of the following statements about DNA replication is false?
- A) It is a semi-conservative process.
- B) Each new DNA molecule contains one original and one new strand.
- C) DNA replication is a random process.
- D) It requires a template strand.
Answer: C) DNA replication is a random process.
What happens at the replication fork during DNA replication?
- A) DNA is synthesized.
- B) DNA strands are separated.
- C) RNA primers are added.
- D) All of the above.
Answer: D) All of the above.
What is the function of the sliding clamp in DNA replication?
- A) To stabilize unwound DNA
- B) To hold DNA polymerase in place
- C) To synthesize RNA primers
- D) To join Okazaki fragments
Answer: B) To hold DNA polymerase in place
Which of the following is a characteristic of eukaryotic DNA replication?
- A) It occurs in the cytoplasm.
- B) It has multiple origins of replication.
- C) It is faster than prokaryotic replication.
- D) It does not require RNA primers.
Answer: B) It has multiple origins of replication.
What is the role of the 5′ cap and poly-A tail in mRNA processing?
- A) They are involved in DNA replication.
- B) They protect mRNA and assist in translation.
- C) They are necessary for DNA synthesis.
- D) They are involved in the formation of Okazaki fragments.
Answer: B) They protect mRNA and assist in translation.
