Question

dna replication is said to be semiconservative. what does this mean?
one strand of the new double helix is made of dna, and the other strand is made of rna.
the old double helix is degraded, and half of its nucleotides are used in the construction of two new double helices.
one of the two resulting double helices is made of two old strands, and the other is made of two new strands.
each new double helix consists of one old and one new strand.
half of the old strand is degraded, and half is used as a template for the replication of a new strand.

Explanation:

Semiconservative DNA replication means that each new DNA molecule consists of one original (old) strand and one newly - synthesized (new) strand.

• Option 1: DNA replication results in DNA - DNA strands, not DNA - RNA strands.
• Option 2: The old double helix is not degraded. It serves as a template.
• Option 3: Both new double helices have one old and one new strand, not one with two old and one with two new.
• Option 5: The whole old strand is used as a template, not half.

Answer:

Each new double helix consists of one old and one new strand.