Question

1.4.2 test (cst): heredity
question 14 of 25
the model represents dna replication.
what does enzyme 1 do?
a. it builds rna strands from sections of dna.
b. it adds nucleotides to the growing strands of dna.
c. it chemically connects the two strands together.
d. it binds to the double helix and unzips the molecule.

Explanation:

Enzyme 1 is helicase. During DNA replication, helicase binds to the double - stranded DNA and breaks the hydrogen bonds between the base pairs, unzipping the DNA molecule. This allows the replication machinery to access the single - stranded DNA templates for the synthesis of new DNA strands. Option A is incorrect as that is the role of RNA polymerase (not related to DNA replication in this context). Option B is the role of DNA polymerase. Option C is not a correct description of helicase's function.

Answer:

D. It binds to the double helix and unzips the molecule.