Which of the following can be used to cut dna so it can be studied?

a. restriction enzymes

b. gel electrophoresis

c. karyotypes

d. haplotypes

The correct answer is option A. restriction enzymes.

Explanation:

Restriction enzymes or restriction endonucleases are enzymes that identify a particular DNA sequence, knowns as restriction site, and cuts the DNA within or adjacent to restriction site.

Restriction enzymes also known as biological scissors because of their ability to cut DNA at a specific sequence.

EcoR I, isolated from the bacterium Escherichia coli, is a restriction enzyme that restricts DNA between the G and A on each strand in a particular DNA sequence.

Thus, The correct answer is option A. restriction enzymes.