Chapter 16

Question 1

4 DNA criteria

Answer 1

Information storage, replication, transmission, variation

Question 2

Information storage

Answer 2

DNA must contain the information necessary to construct an entire organism

Question 3

Replication

Answer 3

Due to its transmission through generations, DNA must be copied

Question 4

Transmission

Answer 4

Information must be passed from cell-to-cell and from parent offspring

Question 5

Variation

Answer 5

DNA must contain variation that accounts for physical differences within each species

Question 6

DNA sugar

Answer 6

Deoxyribose

Question 7

RNA sugar

Answer 7

Ribose

Question 8

What kind of bond hold the stands of the helix together?

Answer 8

Hydrogen bonds

Question 9

Name of the initiation point

Answer 9

Origin of replication

Question 10

What does DNA helicase do?

Answer 10

Enzyme splits the hydrogen bonds between 2 strands

Question 11

What do single strand binding proteins do?

Answer 11

Keep the strands from repairing

Question 12

What does topoisomerase do?

Answer 12

Helps relieve the strain as the untwisting causes tighter twisting ahead

Question 13

What does DNA polymerase III do?

Answer 13

Synthesizes DNA replication ; can’t initiate process without short DNA primer

Question 14

What synthesizes the primer?

Answer 14

RNA primase (only works 5’-3’)

Question 15

What does DNA polymerase do?

Answer 15

Start the new DNA strands from the 3’ end of the RNA primer

Question 16

What does dATP do?

Answer 16

Supplies adenine to DNA and is similar to the ATP of energy metabolism

Question 17

Which way does DNA polymerase III add nucleotides?

Answer 17

5’-3’

Question 18

Leading strand

Answer 18

Continuous ; 5’-3’ ; 1 primer

Question 19

Lagging strand

Answer 19

Discontinuous ; 5’-3’ ; Okazaki fragments ; several primers

Question 20

What does DNA polymerase I do?

Answer 20

Replaces RNA with DNA

Question 21

What does DNA ligase do?

Answer 21

Forms a bond between the newest DNA and the DNA fragment 1

Question 22

What is a telomere?

Answer 22

The protective ends of chromosomes that consist of repetitive sequences ; don’t shorten them

Question 23

Proofreading

Answer 23

Enzymes like nucleuses remove the wrong nucleotides and DNA polymerase fills in the gaps

Question 24

What happens in nucleotide excision?

Answer 24

Nuclear enzyme cuts the damaged DNA and removes it, then DNA polymerase fills the missing nucleotides, finally DNA ligase seals it making the strand complete

Question 25

What do histones do?

Answer 25

They are responsible for the main level of DNA packing in interphase chromatin

Question 26

Makeup of nucleosome

Answer 26

Composed of DNA wound twice around a core of eight histones