Human Genome: Gene Count & DNA Similarity — NEET Biology
📚 Practice ConceptThe total number of genes is estimated at 30,000–much lower than previous estimates of 80,000 to 1,40,000 genes. Almost all (99.9 per cent) nucleotide bases are exactly the same in all humans.
Assertion (A): All nucleotide bases are exactly the same in all humans. Reason (R): The 0.1% variation in human DNA sequences forms the basis of DNA fingerprinting.
View solution & NCERT explanation
Correct answer: D — If the assertion is false but the reason is true.
NCERT states “Almost all (99.9 per cent) nucleotide bases are exactly the same in all humans” - the Assertion removes the qualifier making it false. NCERT explains that the remaining 0.1% variation is what makes DNA fingerprinting possible, making the Reason true. This tests understanding that genetic variation exists despite high similarity.
What does NCERT say about total number genes estimated?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.