Palindromic DNA Sequences — NEET Biology
✅ Asked in NEET 2021A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is: (NEET 2021)
A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is: (NEET 2021)
Answer & NCERT explanation
Correct answer: A — Palindromic Nucleotide sequences
Palindromic nucleotide sequences are recognition sites for restriction endonucleases. These sequences read the same on both DNA strands when read in 5' to 3' direction. Examples include GAATTC for EcoRI. Poly(A) tails are at mRNA ends, degenerate primers have mixed bases, and Okazaki fragments are in DNA replication.
Read more NCERT concept on the PYQ
For example, the following sequences reads the same on the two strands in 5' → 3' direction. This is also true if read in the 3' → 5' direction.
Palindromic sequences are DNA regions that read identically in the 5'→3' direction on both strands, making them symmetric and 'mirror-like'. NTA tests this because restriction enzymes recognize these palindromic sites, which is fundamental to biotechnology applications like recombinant DNA technology. Students commonly confuse palindromic sequences with complementary base pairing or forget that the reading direction matters on both strands. Remember: a true palindromic sequence reads the same when read 5'→3' on the top strand AND 5'→3' on the bottom strand—this is why restriction enzymes (which cut palindromic sites) are so predictable and useful in genetic engineering.
What does NCERT say about For example following sequences?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.