AP BIOLOGY

Detailed explanation-1: -A restriction enzyme is a DNA-cutting enzyme that recognizes specific sites in DNA. Many restriction enzymes make staggered cuts at or near their recognition sites, producing ends with a single-stranded overhang.

Detailed explanation-2: -Assertion :Restriction enzymes cut the strand of DNA to produce sticky ends. Reason: Stickiness of the ends facilities the action of the enzyme DNA polymerase.

Detailed explanation-3: -A ‘sticky’ end is produced when the restriction enzyme cuts at one end of the sequence, between two bases on the same strand, then cuts on the opposite end of the complementary strand. This will produce two ends of DNA that will have some nucleotides without any complementary bases.

Detailed explanation-4: -Usually, a staggered cut by restriction enzymes create overhangs or sticky ends. The restriction enzymes used are EcoRV, SmaⅠ. The restriction enzymes used are EcoR1, HindⅢ.

Detailed explanation-5: -Overhangs are often generated in molecular biology by use of DNA endonucleases. Larger overhangs of several nucleotides, such as those created by restriction endonucleases, are often called “sticky-ends” since a DNA molecule with complimentary sequence in the overhang region can anneal to each other.