15. Which of the following statements about DNA synthesis at the replication fork of a replicating DNA molecule is FALSE?

Question

A. Nucleotides are added at the 3' ends of all the new strands in a replication DNA molecule.
B. Double-stranded DNA synthesis requires both deoxyribonucleotides and ribonucleotides.
C. The sequence of each newly synthesized single strand is identical to that of the parental single strand that served as its template.
D. One of the two new strands must by synthesized in fragments because the two strands have opposite directionality.

Answer 1

The FALSE statement about DNA synthesis at the replication fork of a replicating DNA molecule is:

B. Double-stranded DNA synthesis requires both deoxyribonucleotides and ribonucleotides.

This statement is false because DNA synthesis specifically requires deoxyribonucleotides (dNTPs), not ribonucleotides (rNTPs), which are used for RNA synthesis. During DNA replication, only dNTPs are incorporated into the growing DNA strand. Ribonucleotides are used for synthesizing RNA, such as during transcription, not for DNA replication.