Question 7 of 10intermediate🔧 ApplyShort Answer3 marks

Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base-pair rules.

Correct Answer

Palindromic DNA sequences are sequences of base pairs that read the same on the two strands when orientation of reading is kept the same. For example, reading both strands in 5'→3' direction gives identical sequences.

Five examples of palindromic DNA sequences:

  1. 5'-GAATTC-3'/3'-CTTAAG-5' (EcoRI site)
  2. 5'-AAGCTT-3'/3'-TTCGAA-5'
  3. 5'-GGATCC-3'/3'-CCTAGG-5'
  4. 5'-AGCT-3'/3'-TCGA-5'
  5. 5'-GATC-3'/3'-CTAG-5'

To create a palindromic sequence, follow base-pair rules (A pairs with T, G pairs with C). Ensure that the sequence on one strand reads identical to its complementary strand when both are read in 5'→3' direction. For instance, GAATTC on top strand (5'→3') and CTTAAG on bottom strand, when read 5'→3', also gives GAATTC.

Exercise: EXERCISES | Q: 7 | (Page 15)
For More Understanding

Explanation

The textbook defines palindromes in DNA as sequences that read the same on both strands in the same orientation (5'→3'). The context provides the EcoRI recognition site (GAATTC) as an example. Using the base-pair rules demonstrated in the context (A-T, G-C pairing), students can create additional palindromic sequences. The key principle is that the complementary strand, when reversed, should spell the same sequence as the original strand.

Solution Steps

  1. Step 1: Understand that palindromic DNA reads identically on both strands in 5'→3' direction

  2. Step 2: Apply base-pair rules - A pairs with T, G pairs with C

  3. Step 3: Create sequences where complementary strand (when read 5'→3') matches original sequence

  4. Step 4: Verify each example by writing both strands and checking they read the same

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