Question

when a molecule of double - stranded dna undergoes replication, it results in
oa. one double - stranded dna molecule composed only of entirely new strands
ob. four double - stranded dna molecules, each composed only of old strands of dna
oc. three double - stranded dna molecules, each composed of sections of old and new strands
od. two double - stranded dna molecules, each composed of one new and one old strand

Explanation:

DNA replication is semi - conservative. The original double - stranded DNA unwinds, and each strand serves as a template. New complementary strands are synthesized. So, one replication of a double - stranded DNA molecule results in two double - stranded DNA molecules. Each has one old (template) strand and one new strand.

Answer:

D. two double - stranded DNA molecules, each composed of one new and one old strand