Chapter 13

Question 1

The process by which a DNA molecule is copied; also called DNA synthesis

Answer 1

DNA Replication

Question 2

One of two chemical compounds that cells use to make the building blocks of DNA and RNA. Examples are adenine and guanine.

Answer 2

Purine

Question 3

One of two chemical compounds that cells use to make the building blocks of DNA and RNA. Examples are cytosine, thymine, uracil.

Answer 3

Pyrimidine

Question 4

Two complementary DNA nucleotide bases that pair together to form a “rung of a DNA ladder”

Answer 4

Base Pair

Question 5

Either of the two chains that make up a double helix of DNA, with corresponding positions on the two chains being composed of a pair of complementary bases.

Answer 5

Complementary Strand

Question 6

The DNA sequence that can duplicate itself during mRNA synthesis

Answer 6

Template Strand

Question 7

Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5’ and 3’ directions)

Answer 7

Antiparallel

Question 8

DNA from any cell of all organisms should have a 1:1 ratio of pyrimidine and purine bases.

Answer 8

Chargaff’s Rule

Question 9

The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape.

Answer 9

Double Helix

Question 10

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental molecule, and one newly made strand.

Answer 10

Semiconservative Model

Question 11

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.

Answer 11

Origin of Replication

Question 12

A Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized.

Answer 12

Replication Fork

Question 13

An enzyme that untwists the double helix of DNA at replication forks, separating the two strands and making them available as template strands.

Answer 13

DNA Helicase

Question 14

A protein that breaks, swivels, and rejoins DNA strands. During DNA replication, this helps to relieve strain in the double helix ahead of the replication fork.

Answer 14

Topoisomerase

Question 15

An enzyme that joins RNA nucleotides to make a primer during DNA replication, using the parental DNA strand as a template

Answer 15

Primase

Question 16

An enzyme that catalyzes the elongation of new DNA by the addition of nucleotides to the 3’ end of an existing chain.

Answer 16

DNA Polymerase

Question 17

The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5’S 3’ direction.

Answer 17

Leading Strand

Question 18

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5’ S 3’ direction away from the replication fork.

Answer 18

Lagging Strand

Question 19

A short segment of DNA synthesized away from the replication fork on a template strand during DNA replication. Many are joined together to make up the lagging strand of newly synthesized DNA.

Answer 19

Okazaki Fragment

Question 20

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3’ end of one DNA fragment to the 5’ end of another DNA fragment.

Answer 20

DNA Ligase

Question 21

The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides.

Answer 21

Mismatch Repair

Question 22

A repair system that removes and then correctly replaces a damaged segment of DNA using the undamaged strand as a guide.

Answer 22

Nucleotide Excision Repair

Question 23

An enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides

Answer 23

Nuclease

Question 24

The complex of DNA and proteins that makes up eukaryotic chromosomes.

Answer 24

Chromatin

Question 25

Eukaryotic chromatin that remains highly compact during interphase and is generally not transcribed

Answer 25

Heterochromatin

Question 26

The less condensed form of eukaryotic chromatin that is available for transcription.

Answer 26

Euchromatin