To solve this problem, we need to identify the incorrect statement regarding restriction enzymes. Let's analyze each option:$\newline \bullet$Option 1: They cut the strand of DNA at palindromic sites.$\newline$ - Restriction enzymes recognize specific palindromic sequences in DNA and cut at these sites.$\newline$ - This statement is correct.$\newline \bullet$Option 2: They are useful in genetic engineering.$\newline$ - Restriction enzymes are essential tools in genetic engineering for cutting DNA at specific sites.$\newline$ - This statement is correct.$\newline \bullet$Option 3: Sticky ends can be joined by using DNA ligases.$\newline$ - Sticky ends are single-stranded overhangs created by restriction enzymes.$\newline$ - DNA ligases are enzymes that join DNA fragments by forming phosphodiester bonds.$\newline$ - This statement is correct, not incorrect.$\newline \bullet$Option 4: Each restriction enzyme functions by inspecting the length of a DNA sequence.$\newline$ - Restriction enzymes do not inspect the length of DNA; they recognize specific sequences.$\newline$ - This statement is incorrect.$\newline$Therefore, the wrong statement is Option 4.$\newline$This corresponds to the correct option, which is Option 4.