Question 1

What is DNA replication?

Accepted Answer

The process of creating two identical DNA molecules, from a single original molecule

Question 2

What is conservative DNA replication?

Accepted Answer

An incorrect model of DNA replication where the original DNA molecule is unchanged

(an exact copy is made without changing the original; different from the semiconservative and dispersive models)

Question 3

What is semiconservative DNA replication?

Accepted Answer

A correct model of DNA replication where the new DNA has a helix from the original parent, as well as a newly created helix

(this is the correct model; different from the conservative and dispersive models)

Question 4

What is dispersive DNA replication?

Accepted Answer

An incorrect model of DNA replication where the newly created DNA contains some DNA of the original molecule, dispersed with new DNA

(different from the conservative and semiconservative models)

Question 5

What are the differences between conservative, semiconservative, and dispersive models of DNA replication?

Accepted Answer

Conservative keeps the original unchanged (incorrect)

Semiconservative causes the new DNA to have one strand of old DNA and one strand of new DNA (correct)

Dispersive causes the new DNA to have bits and pieces of the old DNA mixed with new DNA segments (incorrect)

Question 6

What was the Meselson–Stahl experiment?

Accepted Answer

An experiment that indicates DNA replication is semiconservative

Question 7

What is helicase?

Accepted Answer

An enzyme in DNA replication, that unzips the DNA, separating it into single strands and producing the replication fork

(essential for DNA replication, since it separates double strands of DNA into single strands that can be copied)

Question 8

What is the replication fork?

Accepted Answer

A structure that forms during DNA replication, with two branching "prongs" made of a single strand of DNA

(created by helicase)

Question 9

What are primer sites in DNA replication?

Accepted Answer

Short nucleic acid sequences along each DNA strand, that provide an origin site for where replication begins

(DNA polymerase can only attach nucleotides to existing strands of nucleotides, so primer sites are essential foundations)

Question 10

What is DNA polymerase?

Accepted Answer

Molecules in DNA replication that synthesize DNA by adding nucleotides one by one to the DNA chain

(start at the primer and expand)

Question 11

What are the leading and lagging strands?

Accepted Answer

DNA strands involved in DNA replication

The leading strand is replicated continuously in the same direction as the moving fork

The lagging strand is replicated discontinuously in the opposite direction, and made of Okazaki fragments

Question 12

What do 5' (5 prime) and 3' (3 prime) mean in DNA replication?

Accepted Answer

5' and 3' are carbon numbers in the DNA's sugar backbone

The 5' carbon has a phosphate group attached to it, while the 3' carbon has a hydroxyl group

Since the sides are asymmetric, the DNA strand has a "direction"

Question 13

What are Okazaki fragments?

Accepted Answer

Short sequences of DNA nucleotides that are linked together to form the lagging strand in DNA replication

(synthesized discontinuously; linked by DNA ligase)

Question 14

What is a mismatch repair?

Accepted Answer

A system for detecting and repairing issues in DNA

Removes the incorrect nucleotide and adds the proper one in its place

Question 15

What is excision repair?

Accepted Answer

Another repair mechanism in DNA replication that removes a section of DNA with errors, and fills the gap with DNA polymerase

DNA Replication, AP Biology Flashcards