Final answer:
Endonucleases cut DNA at specific sequences within the strand, whereas exonucleases remove nucleotides from the ends of DNA strands. Endonucleases, like HaeIII, are used to create DNA fragments for laboratory processes, while exonucleases trim DNA for further modification or repair.
Step-by-step explanation:
The question pertains to the enzymes involved in DNA cleavage. The endonucleases are enzymes that cut DNA at specific sequences within the strand, as opposed to exonucleases which remove nucleotides from the ends of DNA strands. Endonucleases recognize specific nucleotide sequences in the DNA molecule and make cuts at those precise locations. For example, restriction enzymes like HaeIII are a type of endonuclease used in molecular biology to cut DNA at specific sites to create fragments for various laboratory procedures, such as cloning and DNA analysis. An exonuclease will remove nucleotides one by one from an end (either the 5′ end or the 3′ end) of the DNA molecule. This trimming process either prepares the DNA strand for further modification or is part of the DNA repair mechanisms.