Question

after dna replication is completed, —.
o there are four double helices
o one dna double helix consists of two old strands and one dna double helix consists of
two new strands
o each of the four dna strands consists of some old strand parts and some new strand
parts
o each new dna double helix consists of two new strands
o each new dna double helix consists of one old dna strand and one new dna strand

Explanation:

DNA replication follows the semi - conservative model. In this model, the double - stranded DNA unwinds, and each old strand serves as a template for the synthesis of a new complementary strand. So, after replication, each new DNA double helix consists of one old (parent) DNA strand and one new (daughter) DNA strand.

Answer:

each new DNA double helix consists of one old DNA strand and one new DNA strand