Question

Some restriction endonucleases are capable of producing blunt ends; others can generate "sticky" ends. Some restriction endonucleases are capable of producing blunt ends; others can generate "sticky" ends. True False

Answer 1

The statement is true as restriction endonucleases indeed can create either blunt or sticky ends in DNA, which are crucial in the formation of recombinant DNA and biotechnological applications.

Step-by-step explanation:

The statement is true; some restriction endonucleases produce blunt ends, while others generate sticky ends. The process of creating recombinant DNA (rDNA) involves using restriction enzymes like BamHI or HaeIII to cut DNA in very specific ways. BamHI cuts DNA at particular points to produce DNA fragments with sticky ends, which are overhanging sequences that can form hydrogen bonds with complementary sticky ends of other DNA fragments. On the other hand, enzymes like HaeIII can cut DNA to produce blunt ends, which do not have overhanging sequences and can directly ligate to any other blunt-ended DNA fragment. The addition of complementary tails, such as poly 'G' for the target DNA and poly 'C' for the vector DNA, is sometimes used to facilitate the joining of blunt-ended DNAs.

Plasmids, often employed as vectors in cloning procedures, can carry these DNA fragments from one organism to another. In the case of blunt end ligation, enzymes such as terminal transferase are sometimes used to add nucleotide tails to facilitate the annealing of the DNA segments. Plasmids can have specific properties engineered into them, such as antibiotic resistance genes, which help in selecting for bacteria that contain the recombinant DNA.

Answer 2

The correct answer is "True".

Step-by-step explanation:

Restriction endonucleases are a special type of enzymes that catalyze the hydrolysis of DNA sequences at specific sites. Some restriction endonucleases are capable of producing blunt ends, leaving double stranded DNA fragments. However, the most common outcome of the restriction endonucleases hydrolysis is the generation of "sticky" ends with DNA fragments having some nucleotides in a single stranded form.