Question

The recognition sequence of restriction enzyme 'A' is GGCC and that of 'B' is GAATAC. Which statement among the following is the true regarding the probable frequency of cutting sites in a genome?

• A. Both 'A' and 'B' cut equally frequently.
• B. 'A' cuts once every 676 nucleotides and 'B' 1024 nucleotides.
  
• C. 'A' cuts once every 256 nucleotides and 'B' 4096 nucleotides.
• D. 'A' cuts once every 256 nucleotides and 'B' 1024 nucleotides.

Answer 1

The correct option is C 'A' cuts once every 256 nucleotides and 'B' 4096 nucleotides.

If the restriction enzyme A can recognize GGCC then its cutting frequency would be $4^4$ = 256 and that of B enzyme would be $4^6$ = 4096. Hence, for enzyme A can find the recognition sequence to cut after every 256 bps and for B it is 4096 bps.

So, the correct answer is ''A' cuts once every 256 nucleotides and 'B' 4096 nucleotides.'