Because each old strand of the parent molecule serves a(n) _________ for and is present in each new daughter strand, the process of DNA replication can be described as __________.

• A. Semiconservative; template
• B. Template; semiconservative
• C. Template; conservative
• D. Semiconservative; conservative

Answer: (B)

DNA replication is semiconservative. The two strands of the parent double helix separate, and each old strand acts as a template to guide the synthesis of a new complementary strand. Because of this, every new daughter DNA molecule contains one original strand and one newly built strand. The old strand is used as the pattern for the new strand (the template), and it is retained in the daughter molecule, which is what semiconservative replication means. The other models would imply either both new strands form a completely new double helix or that the old strands are not retained in the daughters, which isn’t supported by how replication actually occurs.