Question

which statement is best supported by the results of this experiment?
a. cell division produces four identical dna strands.
b. the two dna strands are replicated in opposite directions.
c. several proteins are involved in dna replication.
d. dna replication is a semiconservative process.

Explanation:

DNA replication is a semiconservative process. In semiconservative replication, each new DNA molecule consists of one original (parent) strand and one newly synthesized strand. As shown in the diagram, the original DNA (blue) is replicated, and each of the new DNA molecules has one original (blue) strand and one new (radioactively - labeled/orange) strand.

• Option A: Cell division produces two daughter cells, each with a full set of DNA. But the diagram focuses on DNA replication, not cell division producing four DNA strands.
• Option B: The diagram does not show anything about the direction of DNA strand replication.
• Option C: While proteins are involved in DNA replication (like DNA polymerase, helicase etc.), the diagram does not provide evidence for the involvement of several proteins.
• Option D: The diagram clearly shows that each new DNA molecule has one original strand (blue) and one new strand (orange/radioactively - labeled), which is the hallmark of semiconservative replication.

Answer:

D. DNA replication is a semiconservative process.