Molecular Basis of Inheritance Practice Questions
NEET · Biology · 976 free MCQs with instant results and detailed explanations.
976
Total
204
Easy
426
Medium
346
Hard
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Topics in Molecular Basis of Inheritance
DNA Structure and Replication
133
Transcription
144
Translation
145
Genetic Code
129
Gene Regulation
126
Human Genome Project
152
DNA Fingerprinting
147
Sample Questions from Molecular Basis of Inheritance
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the basic structural unit of DNA?
A.
Nucleotide
B.
Amino acid
C.
Monosaccharide
D.
Fatty acid
Show Answer & Explanation
Correct Answer: A
Nucleotides are the building blocks of DNA, consisting of a phosphate group, a sugar, and a nitrogenous base.
Q2
Easy
In DNA replication, which enzyme is responsible for unwinding the DNA double helix?
A.
DNA polymerase
B.
Helicase
C.
Ligase
D.
Primase
Show Answer & Explanation
Correct Answer: B
Helicase is the enzyme that unwinds the DNA double helix, allowing the replication process to take place.
Q3
Easy
What type of bond holds the two strands of DNA together?
A.
Peptide bonds
B.
Ionic bonds
C.
Hydrogen bonds
D.
Covalent bonds
Show Answer & Explanation
Correct Answer: C
Hydrogen bonds between complementary nitrogenous bases hold the two strands of DNA together.
Q4
Medium
Which of the following statements about the structure of DNA is incorrect?
A.
DNA is composed of nucleotides.
B.
The sugar in DNA is ribose.
C.
DNA strands are antiparallel.
D.
A pairs with T, and G pairs with C.
Show Answer & Explanation
Correct Answer: B
The sugar in DNA is deoxyribose, not ribose. Ribose is found in RNA. Therefore, option B is the incorrect statement about DNA structure.
Q5
Medium
What is the backbone of a DNA molecule composed of?
A.
Sugar and phosphate groups
B.
Nitrogenous bases
C.
Ribose and nitrogenous bases
D.
Amino acids
Show Answer & Explanation
Correct Answer: A
The backbone of a DNA molecule is made up of alternating sugar (deoxyribose) and phosphate groups, providing structural support to the molecule.
Q6
Medium
Which enzyme is responsible for synthesizing new DNA strands during replication?
A.
DNA helicase
B.
DNA polymerase
C.
Ligase
D.
Primase
Show Answer & Explanation
Correct Answer: B
DNA polymerase is the enzyme that synthesizes new DNA strands by adding nucleotides complementary to the template strand during replication.
Q7
Medium
What is the role of helicase during DNA replication?
A.
Synthesize RNA primers
B.
Unwind the DNA double helix
C.
Join Okazaki fragments
D.
Add nucleotides to the growing strand
Show Answer & Explanation
Correct Answer: B
Helicase is the enzyme responsible for unwinding the DNA double helix, allowing access for the replication machinery.
Q8
Hard
Which of the following statements about the structure of DNA is incorrect?
A.
DNA is composed of nucleotides.
B.
The sugar in DNA is ribose.
C.
DNA strands are antiparallel.
D.
A and T, C and G form complementary base pairs.
Show Answer & Explanation
Correct Answer: B
The sugar in DNA is deoxyribose, not ribose. Ribose is found in RNA, making option B incorrect while the other statements are true.
Q9
Hard
In the Meselson-Stahl experiment, which method was used to distinguish between 'old' and 'new' DNA strands?
A.
Ultracentrifugation
B.
Chromatography
C.
Electrophoresis
D.
PCR amplification
Show Answer & Explanation
Correct Answer: A
Ultracentrifugation was used in the Meselson-Stahl experiment to separate DNA based on density, distinguishing old (heavy) DNA from newly synthesized (light) DNA.
Q10
Hard
What is the primary role of helicase during DNA replication?
A.
To synthesize RNA primers.
B.
To unwind the DNA double helix.
C.
To proofread the newly synthesized DNA.
D.
To add nucleotides to the growing DNA strand.
Show Answer & Explanation
Correct Answer: B
Helicase unwinds the DNA double helix by breaking hydrogen bonds between base pairs, allowing replication machinery to access the strands.
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Molecular Basis of Inheritance — NEET Biology Practice Questions Online
This page contains 976 practice MCQs for the chapter Molecular Basis of Inheritance in NEET Biology. The questions are organized by difficulty — 204 easy, 426 medium, 346 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 7 topics, giving you comprehensive coverage of the entire chapter.