Chapter 16: DNA replication

Question 1

What carries a vast array of hereditary information?

Answer 1

Sequences of bases

Question 2

Orgins of replication eukaryote vs. prokaryote

Answer 2

Eukaryote can have hundreds of origins

Prokaryotes only have one origin of replication

Question 3

What direction does replication occur in?

Answer 3

Trick question happens in both directions from origin of replication

Question 4

Helicases

Answer 4

Enzymes that untwist the double helix at the replication forks

Question 5

Single strand binding proteins

Answer 5

Bind to and stabilize single-stranded DNA

Held hold DNA strands apart

Question 6

Topoisomerase

Answer 6

Relieves strain in the DNA ahead of the replication fork

Question 7

Primase

Answer 7

Adds RNA primer

Short segments of RNA

Question 8

What end can DNA polymerases add to?

Answer 8

Only 3’ end

Question 9

DNA polymerases (collective)

Answer 9

Catalyze the elongation of new DNA at a replication fork

Question 10

Difference between dATP and ATP

Answer 10

ATP has ribose

dATP has deoxyribose

Question 11

Leading strand

Answer 11

Moves towards the replication fork

Question 12

Lagging strand

Answer 12

DNA polymerase must work in the direction away from the replication fork

Question 13

Okazaki fragments

Answer 13

Synthesizes the lagging strand as a series of segments

The segments are then joined together by DNA ligase

Question 14

DNA Polymerase III

Answer 14

Synthesizes new DNA by adding nucleotides to an RNA primer or a pre-existing DNA strand

Question 15

DNA Polymerase I

Answer 15

Removes RNA nucleotides of primer from 5’ end and replaces them with DNA nucleotides

Question 16

DNA ligase

Answer 16

Joins Okazaki fragments

Joins 3’ end of DNA that replaces primer to rest of leading strand of DNA

Question 17

Mismatch Repair

Answer 17

Repair enzymes and correct errors in base pairing

Question 18

Nuclease

Answer 18

Cuts out and replaces damaged stretches of DNA

Nucleotide excision repair

Question 19

Telomeres

Answer 19

Postpone the erosion of genes near the ends of DNA molecules

Question 20

Telomerase

Answer 20

Catalyzes the lengthening of telomeres in germ cells

Vital so whole genes do not get replaced

Question 21

Bacterial chromosome

Answer 21

Is a double-stranded, circular DNA molecule associated with a small amount of protein

Question 22

Interphase and Chromatin

Answer 22

At interphase chromatin is organized in a 10-nm fiber

Later is compacted into a 30-nm fiber

Question 23

Euchromatin

Answer 23

Loosely packed chromatin

Question 24

Heterochromatin

Answer 24

Highly condensed chromatin

So condensed that cells have trouble expressing genes

Centromeres and telomeres mostly

Question 25

What does a lack of telomerase result in?

Answer 25

Reduction in chromosome length

Question 26

What does the semi-conservative nature of DNA permit for?

Answer 26

Allows for daughter cells to inherit the different nucleotides Example: In the e. coli problems the daughter cells always inherit the nucleotides

Question 27

What can fix hypoanthime?

Answer 27

Nuclease DNA polymerase DNA ligase

Question 28

What will a lack of helicase result in?

Answer 28

No replication fork

Question 29

Polytene Chromosomes

Answer 29

Form by replication without seperation

Question 30

Histone H1

Answer 30

Is not present in nucleosome bead Instead it draws the nucleosomes together

Question 31

Rank the levels of organization from smallest to largest

Answer 31

Nucleosome 30 nm Looped domain

Question 32

Transformation in Bacteria

Answer 32

Means external DNA is taking into a cell

Question 33

What is needed for both prokaryotes and eukaryotes to perform DNA replication?

Answer 33

Primers Origin of replication dNTP Double the amount of DNA

Question 34

Okazaki fragments have...

Answer 34

5' RNA 3' DNA

Question 35

Which enzyme catalyzes the elongation of DNA

Answer 35

DNA polymerase III

Question 36

Which enzymes work to repair a thymine dimer

Answer 36

Endonuclease DNA polymerase I DNA ligase

Question 37

Histones charge

Answer 37

Postive

Question 38

DNA charge

Answer 38

Negative

Question 39

Tetramers

Answer 39

Two types of tetramers form an octamer

Question 40

Does DNA contain phosphorous?

Answer 40

Yes