Suppose a restriction enzyme recognizes the six-base sequence aagctt ttcgaa in a double strand of dna . Between which two nucleotides on each strand would the enzyme have to cut to produce a fragment with sticky ends that are four bases long

Explanation:

1. A restriction enzyme, restriction endonuclease, an enzyme that cleaves DNA into small fragments at or near specific recognition sites (different  restriction enzyme has different restriction site) within molecules known as restriction sites.

2. Restriction enzymes are found in archaea and bacteria.

3 And in  bacteria and archaea they provide a defence mechanism against invading viruses.

4. Each restriction enzyme cut at the specific site, because each restriction enzyme have specific recognition site.

it would lead to upper respiratory infections and pneumonia.