Question

Which of the following statements is incorrect?

o hind-ii always cut DNA molecules at a particular point by recognizing a specific sequence of 4 base pairs.
o besides hind-ii, today we know more than 900 restriction name ecori comes from escherichia coli ry 13.
o restriction endonucleases are used in genetic engineering to form recombinant molecules of DNA

Answer 1

The correct answer is option 1. The incorrect statement is that Hind-II always recognizes a specific sequence of 4 base pairs. Restriction endonucleases like Hind-II typically recognize specific palindromic sequences longer than four base pairs, and they are crucial tools in genetic engineering for creating recombinant DNA.

Step-by-step explanation:

The statement that is incorrect is the one asserting that Hind-II always cuts DNA molecules at a particular point by recognizing a specific sequence of 4 base pairs. This is inaccurate because restriction endonucleases, including Hind-II, typically recognize specific palindromic DNA sequences that are often longer than four bases. In fact, EcoRI, for example, recognizes the six-base sequence 5'GAATTC3' and cuts within this sequence, resulting in sticky ends.

Furthermore, it is true that there are currently more than 900 named restriction endonucleases, and the name EcoRI indeed originates from the bacterium Escherichia coli. These restriction enzymes are a fundamental tool in genetic engineering and biotechnology for creating recombinant DNA molecules. By cutting DNA sequences at specific recognition sites and generating either sticky or blunt ends, restriction endonucleases enable the splicing together of DNA fragments from different sources to form new genetic combinations, with recombinant molecules of DNA.