(a) : Palindromes are groups of letters that form the same words when read both forward and backward, e.g., "MADAM". As against a word-palindrome where the same word is read in both directions, the palindrome in DNA is a sequence of base pairs that reads same on the two strands when orientation of reading is kept the same. For example, the following sequences read the same on the two strands in 5′‌3′ direction. This is also true if read in the 3′‌‌5′ direction. In this case, it is 5′− GAATTC ‌−3′ 3′−‌ CTTAAG ‌−5′