DNA Structure and Replication Practice

What is happening to the DNA molecule in the figure? (Explain the first step in DNA replication)

• The DNA molecule is being transcribed into RNA.

• The DNA molecule is being translated into proteins.

• The DNA molecule is being unzipped and separated into two strands.

• The DNA molecule is being repaired.

What happens to the DNA molecule during the second step of DNA replication?

• The DNA strands are separated by helicase.

• New nucleotides are added to the existing DNA strands.

• The DNA strands are joined by ligase.

• The DNA is packaged into chromosomes.

What happens during the third step of DNA replication?

• The DNA strands are separated by helicase.

• Primase synthesizes RNA primers.

• Two identical DNA strands result.

• Ligase joins Okazaki fragments.

What does it mean that the two strands of DNA are complementary?

• They have identical sequences.

• They are mirror images of each other.

• They have sequences that pair with each other according to base pairing rules.

• They are unrelated in sequence.

What is DNA replication?

• The process of copying a DNA molecule to produce two identical DNA molecules.

• The process of converting DNA into RNA.

• The process of breaking down DNA into nucleotides.

• The process of synthesizing proteins from DNA.

(True or False) The process of DNA replication results in a copy of the original DNA molecule.

• True

• False

(True or False) DNA does not have to break apart to be copied.

• True

• False

(True or False) After DNA replication is complete, there are two new DNA molecules; one molecule has both of the original strands and one molecule has two new strands of DNA.

• True

• False

Where does DNA replication happen?

• In the cytoplasm

• In the nucleus

• In the mitochondria

• In the ribosome

Place the steps of DNA replication in the correct order.

• DNA is unzipped by helicase.

• The complementary bases are added to each template strand by DNA polymerase.

• The 2 new strands are proofread for errors by DNA polymerase and then DNA winds up.