Question

the action of helicase creates —.
primers and dna fragments
dna fragments and replication bubbles
replication forks and replication bubbles
dna fragments and replication forks
primers and replication bubbles

Explanation:

Helicase is an enzyme that unwinds the DNA double - helix. When it acts, it creates replication forks. Replication forks are the Y - shaped structures where DNA replication occurs. DNA fragments (such as Okazaki fragments on the lagging strand) are formed during replication, but helicase's direct action is related to creating the replication fork. Primers are short RNA or DNA sequences that initiate DNA synthesis, and replication bubbles are formed due to the unwinding of DNA (helicase action is part of creating the conditions for replication bubbles, but more directly creates replication forks).

Answer:

replication forks and replication bubbles