NEET Biology Molecular Basis of Inheritance MCQs Set 24

Biology Objective Questions and Answers: Molecular Basis of Inheritance

Access targeted multiple-choice questions for Molecular Basis of Inheritance designed to align with the latest NEET academic syllabus for NEET Biology. These objective practice sets help students evaluate their conceptual understanding and improve exam readiness.

Download Molecular Basis of Inheritance MCQs with Answers

View or download the dedicated Molecular Basis of Inheritance MCQ resource below. Practicing these 50 objective questions regularly builds familiarity with standard exam patterns and helps secure higher marks in final Biology evaluations.

Multiple Choice Questions

Question 1: Consider the statements: (A) RNA was the first genetic material, (B) 5-methyl uracil is found in RNA, (C) DNA polymerase III does not require an RNA primer, (D) the RNA primer is formed over the 3' end of the template strand. The correct statements are:
(a) (A) and (B)
(b) (B) and (C)
(c) (A) and (D)
(d) (A) and (C)
Show Answer & Explanation

Answer: (c) (A) and (D)

Explanation:
1. RNA is believed to be the first genetic material.
2. The RNA primer anneals at the 3' end of the template strand.

Teacher's Note:
1. 5-methyl uracil (thymine) is in DNA, and DNA polymerase needs a primer to begin synthesis.

Question 2: E. coli containing N15-N15 DNA is allowed to grow for 80 minutes in a medium containing N14 (generation time 20 minutes). What percentage of DNA molecules are of light density and hybrid density?
(a) 87.5% light and 12.5% hybrid
(b) 75% light and 25% hybrid
(c) 25% light and 75% hybrid
(d) 12.5% light and 87.5% hybrid
Show Answer & Explanation

Answer: (a) 87.5% light and 12.5% hybrid

Explanation:
1. In 80 minutes there are 4 generations, giving 16 DNA molecules.
2. Two are hybrid (N15-N14) and 14 are light, so hybrid is 12.5% and light is 87.5%.

Teacher's Note:
1. Heavy DNA disappears after the first generation.

Question 3: Which of the following is NOT found in DNA?
(a) Deoxyribose sugar
(b) 5-methyl uracil
(c) Demethylated thymine
(d) H3PO4
Show Answer & Explanation

Answer: (c) Demethylated thymine

Explanation:
1. Thymine is 5-methyl uracil, so it is present in DNA.
2. Demethylated thymine is uracil, which is found only in RNA.

Teacher's Note:
1. Deoxyribose and phosphate are parts of DNA nucleotides.

Question 4: Match Column I with Column II: (A) Replication (B) Transcription (C) Translation (D) Reverse transcription (E) Ribosome. Column II: (i) RNA to DNA (ii) mRNA to protein (iii) DNA to mRNA (iv) DNA to DNA (x) rRNA + protein.
(a) A-i, B-ii, C-iii, D-iv, E-x
(b) A-ii, B-i, C-iii, D-iv, E-x
(c) A-iii, B-iv, C-ii, D-i, E-x
(d) A-iv, B-iii, C-ii, D-i, E-x
Show Answer & Explanation

Answer: (d) A-iv, B-iii, C-ii, D-i, E-x

Explanation:
1. Replication is DNA to DNA, transcription is DNA to mRNA, translation is mRNA to protein and reverse transcription is RNA to DNA.
2. The ribosome is made of rRNA and protein.

Teacher's Note:
1. Option (d) matches all five pairs.

Question 5: A segment of DNA contains 20,000 base pairs. The number of phosphate molecules in it is:
(a) 20,000
(b) 40,000
(c) 10,000
(d) 5,000
Show Answer & Explanation

Answer: (b) 40,000

Explanation:
1. Each base pair has two nucleotides, one on each strand, and each nucleotide has one phosphate.
2. So 20,000 bp have 40,000 phosphates.

Teacher's Note:
1. Count nucleotides, not base pairs.

Question 6: A DNA segment has 200 molecules of adenine and 200 molecules of cytosine. The total number of purine bases in the segment is:
(a) 800
(b) 400
(c) 100
(d) 200
Show Answer & Explanation

Answer: (b) 400

Explanation:
1. In double-stranded DNA A = T and G = C, so A = T = 200 and G = C = 200, a total of 800 bases.

Teacher's Note:
1. Purines (A + G) are half of the total, which is 400.

Question 7: Which statement is NOT true for the base ratio of DNA?
(a) Base ratio is constant for a given species
(b) Base ratio is variable for different species
(c) Base ratio does not depend on the age of the organism
(d) Base ratio is different for different tissues of an organism
Show Answer & Explanation

Answer: (d) Base ratio is different for different tissues of an organism

Explanation:
1. The base composition of DNA is characteristic of a species, and does not change with age, tissue or environment.
2. All cells of an organism carry the same DNA.

Teacher's Note:
1. So statement (d) is false.

Question 8: Consider: (A) a histone octamer is made of 5 types of histone proteins, (B) a typical nucleosome contains 200 bp of DNA, (C) histones are organised into a unit of eight molecules called the histone octamer, (D) negatively charged DNA is wrapped around the positively charged histone octamer to form a nucleosome. How many statements are correct?
(a) One
(b) Two
(c) Three
(d) Four
Show Answer & Explanation

Answer: (c) Three

Explanation:
1. The octamer has 4 types of histones (H2A, H2B, H3 and H4), two of each, so (A) is wrong.
2. The other three statements are correct.

Teacher's Note:
1. Histones are basic because they are rich in lysine and arginine.

Question 9: In the formation of a phosphodiester bond, a phosphate group joins:
(a) 5'-OH of one sugar and 2'-OH of the next sugar
(b) 3'-OH of one sugar and 5'-OH of the next sugar
(c) 3'-OH of one sugar and 2'-OH of the next sugar
(d) 5'-OH of one sugar and 1'-OH of the next sugar
Show Answer & Explanation

Answer: (b) 3'-OH of one sugar and 5'-OH of the next sugar

Explanation:
1. The phosphate links the 3' carbon of one nucleotide to the 5' carbon of the next.
2. This gives a sugar-phosphate backbone with 5' to 3' polarity.

Teacher's Note:
1. DNA polymerase adds nucleotides to a free 3'-OH.

Question 10: The same amino acid sequence of a polypeptide can be coded by more than one nucleotide sequence in mRNA. This explains which property of the genetic code?
(a) Universal nature
(b) Degeneracy
(c) Unambiguous nature
(d) Comma-less or continuous reading
Show Answer & Explanation

Answer: (b) Degeneracy

Explanation:
1. Different codons can code for the same amino acid, which is degeneracy.
2. Mostly the third base differs.

Teacher's Note:
1. This makes the code robust to some mutations.

Question 11: Translation involves the transfer of genetic information from:
(a) A polymer of amino acids to a polymer of carbohydrates
(b) A polymer of deoxynucleotides to a polymer of nucleotides
(c) A polymer of nucleotides to a polymer of amino acids
(d) A polymer of amino acids to proteins
Show Answer & Explanation

Answer: (c) A polymer of nucleotides to a polymer of amino acids

Explanation:
1. In translation the nucleotide sequence of mRNA is decoded into an amino acid sequence.
2. This is a polymer of nucleotides to a polymer of amino acids.

Teacher's Note:
1. Option (b) describes transcription.

Question 12: Select the incorrect statement for RFLP.
(a) It is the basis of DNA fingerprinting
(b) It is due to variable length of restriction fragments
(c) It is due to variable number of minisatellites
(d) It is the same for all human beings
Show Answer & Explanation

Answer: (d) It is the same for all human beings

Explanation:
1. RFLP shows individual differences in fragment lengths, caused by variable tandem repeats.
2. It is the basis of DNA fingerprinting, so it cannot be the same for all humans.

Teacher's Note:
1. Identical twins are the exception.

Question 13: An allelic sequence variation is traditionally described as DNA polymorphism if more than one allele at a locus shows:
(a) Frequency greater than 0.01
(b) Frequency less than 0.01
(c) Frequency greater than 1.0
(d) Frequency less than 0.01%
Show Answer & Explanation

Answer: (a) Frequency greater than 0.01

Explanation:
1. DNA polymorphism requires that the variant allele be present in more than 1% (frequency greater than 0.01) of the population.
2. Rarer variants are called mutations.

Teacher's Note:
1. A frequency cannot exceed 1.0.

Question 14: Which statement is incorrect with respect to the lac operon?
(a) There is a single promoter for the three structural genes lac z, lac y and lac a
(b) It forms polycistronic mRNA
(c) Glucose results in induction of the lac operon
(d) The repressor protein shows negative control
Show Answer & Explanation

Answer: (c) Glucose results in induction of the lac operon

Explanation:
1. The lac operon is induced by lactose (allolactose), not by glucose.
2. Glucose does not induce it.

Teacher's Note:
1. The operon has one promoter and gives polycistronic mRNA, and the repressor exerts negative control.

Question 15: In the structure of normal DNA, replacement of one nitrogenous base by another is called A, and replacement of adenine by guanine is called B. A and B are:
(a) A substitution, B transition
(b) A point mutation, B transversion
(c) A frameshift mutation, B transversion
(d) Both (b) and (c)
Show Answer & Explanation

Answer: (a) A substitution, B transition

Explanation:
1. A base replaced by another is a substitution (a type of point mutation).
2. Adenine to guanine is a purine-to-purine change, called a transition.

Teacher's Note:
1. A transversion is a purine-to-pyrimidine change.

Question 16: Which region of the transcription unit is located towards the 3' end of the coding strand and usually defines the end of transcription?
(a) Promoter
(b) Structural gene
(c) Terminator
(d) Coding strand
Show Answer & Explanation

Answer: (c) Terminator

Explanation:
1. A transcription unit has a promoter at the 5' end, the structural gene, and the terminator at the 3' end of the coding strand.
2. The terminator signals the end of transcription.

Teacher's Note:
1. The promoter is the RNA polymerase binding site.

Question 17: Find the incorrect statement about the results of the Human Genome Project.
(a) Dystrophin is the largest gene of the human genome
(b) Chromosome Y has a minimum of 231 genes
(c) SNPs have been identified at about 2.4 million locations
(d) The functions of over 50% of discovered genes are unknown
Show Answer & Explanation

Answer: (c) SNPs have been identified at about 2.4 million locations

Explanation:
1. NCERT states that about 1.4 million SNPs were identified, so 2.4 million is incorrect.

Teacher's Note:
1. Dystrophin is the largest gene, chromosome Y has the fewest genes (231) and the function of over 50% of genes was unknown at that time.

Free study material for Biology

Molecular Basis of Inheritance Objective Questions & Solutions for NEET Biology

Download Multiple Choice Questions: Molecular Basis of Inheritance (NEET Biology)

Test your conceptual understanding of Molecular Basis of Inheritance with these targeted multiple-choice questions. Designed in alignment with the latest NEET curriculum for NEET Biology, these problem sets build accuracy and prepare students for objective exams.

Concept Clarification for Molecular Basis of Inheritance

Built using the official NCERT book for NEET, these Biology objective sets provide reliable academic guidance. Pair your practice with our recommended NCERT solutions to master optimal problem-solving approaches.

Additional Study Resources for NEET Biology

Explore our broader library of printable assignments, chapter notes, and mock tests designed to support continuous revision and secure higher marks in NEET assessments.

FAQs

Where can I access latest NEET Biology Molecular Basis of Inheritance MCQs Set 24?

You can get most exhaustive NEET Biology Molecular Basis of Inheritance MCQs Set 24 for free on StudiesToday.com. These MCQs for NEET Biology are updated for the 2026-27 academic session as per NEET examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Biology NEET material?

Yes, our NEET Biology Molecular Basis of Inheritance MCQs Set 24 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the NEET paper is now competency-based.

How do practicing Biology MCQs help in scoring full marks in NEET exams?

By solving our NEET Biology Molecular Basis of Inheritance MCQs Set 24, NEET students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Biology.

Do you provide answers and explanations for NEET Biology Molecular Basis of Inheritance MCQs Set 24?

Yes, Biology MCQs for NEET have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused NEET exams.

Can I practice these Biology NEET MCQs online?

Yes, you can also access online interactive tests for NEET Biology Molecular Basis of Inheritance MCQs Set 24 on StudiesToday.com as they provide instant answers and score to help you track your progress in Biology.