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

A

Explanation:

Upon discovery of the DNA structure by Watson and Crick, three models were proposed in the 1950's to explain the method in which DNA replicated. One of these models stood out, this model is the SEMICONSERVATIVE MODEL.

In the semiconservative model, it was proposed that a single DNA strand serves as a template for synthesizing its complementary strand. The cell replicates its DNA in the S-phase of interphase. In this phase, the the double-helix of the DNA is separated into two single strands. An enzyme called DNA polymerase then synthesizes a new strand complementary to each separated single strand.

At the end, the replicated double-stranded DNA now contains one old template strand and a new complementary strand.

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

i think the answer is b.