Question

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

Explanation:

• Option A: DNA replication is semiconservative. 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) strands are separated, and new strands (orange) are synthesized. Each of the resulting DNA molecules has one original (blue) and one new (radioactively - labeled/orange) strand, which is characteristic of semiconservative replication.
• Option B: Cell division (mitosis or meiosis) is not directly shown or supported by the diagram. The diagram focuses on DNA replication, not the process of cell division and the number of DNA strands produced during cell division (mitosis produces two cells with the same amount of DNA as the parent cell, and meiosis produces four cells with half the amount of DNA in a different context than simple DNA strand numbering as described in this option).
• Option C: The diagram does not provide information about the number of proteins involved in DNA replication. It only shows the structure of the DNA before and after replication in terms of strand composition.
• Option D: The diagram does not indicate the direction of DNA strand replication. It only shows the semiconservative nature of replication (combination of old and new strands), not the orientation (5' - 3' or 3' - 5') of replication on the two strands.

Answer:

A. DNA replication is a semiconservative process.