Molecular Basis of Inheritance

Question 1

What did Fredrick Griffith do

Answer 1

Two bacterial strains
—S cells which are pathogenic
—R cells harmless (nonpathogenic)

Question 2

Fredrick Griffith Experiment

Answer 2

Living s cells = mouse die
Living r cells = mouse healthy
Heat-killed s cells = mouse healthy
Mix heat-killed s cells + living r cells = mouse dies

Question 3

What did Alfred Hershey and Martha Chase do

Answer 3

T2 is a virus that infects bacteria which have a very basic structure (DNA enclosed in a protein coat)

Question 4

Alfred Hershey and Martha Chase’s experiment

Answer 4

Used radioactive isotopes to label/track DNA or protein
PROTEIN=35P
DNA=32P
OUTCOMES
–Protein is heritable when presented to 35P
–DNA is heritable when presented to 32P

Question 5

What is the origin of replication?

Answer 5

A place to start

Question 6

What is the unwinding of replication?

Answer 6

From helical structure so that enzymes
can access the template

Question 7

What is the priming of replication?

Answer 7

a set of nucleotides for enzymes to start from

Question 8

What is the elongation of replication?

Answer 8

enzymes to add complementary

Question 9

What is the ligating of replication?

Answer 9

fusing the strands at the end

Question 10

Characteristics of DNA replication (5)

Answer 10

1) Is highly accurate
2) Requires multiple enzymes and proteins
3) Requires energy
4) Requires a template (existing genome to copy)
5) Requires individual nucleotides to pair with template

Question 11

The lagging strand does what?

Answer 11

Synthesized into Okazaki segments
Has DNA Polymerase 1 for replacing RNA primer with DNA

Question 12

The leading strand does what?

Answer 12

Synthesized continuously
Has DNA Polymerase 3 which synthesizes on leading strand going in 5’–>3’ direction

Question 13

Ligating does what?

Answer 13

Uses ligase to fuse Okazaki fragments on the lagging strand

Question 14

DNA Helicase does what?

Answer 14

enzyme that untwists and separates DNA double-strand

Question 15

Single-stranded binding protein does what?

Answer 15

stabilizes single-stranded DNA

Question 16

Topoisomerase does what?

Answer 16

an enzyme that relieves the strain of untwisting DNA at
the other end

Question 17

DNA Primase does what?

Answer 17

synthesizes the RNA primer on the DNA
template

Question 18

DNA polymerase III

Answer 18

Synthesizes on the leading strand in the 5’–>3’ direction

Question 19

DNA polymerase I

Answer 19

replaces RNA primer with DNA

Question 20

DNA Ligase does what

Answer 20

fuses Okazaki fragments on the lagging strand

Question 21

DNA Polymerase features (5)

Answer 21

1) Requires template
2) Requires primer
3) dNTPs (monomers)
4) 5’–>3’ direction
5) Proofreading

Question 22

Proofreading does what?

Answer 22

Looking over errors in DNA Polymerase

Question 23

Mismatch Repair does what?

Answer 23

other enzymes remove and replace incorrectly paired nucleotides
MUT enzymes

Question 24

Excision Repair does what?

Answer 24

enzymes cut out a segment of DNA that is incorrect and then fill in the gap
-Nucleases – cut out error
-DNA polymerase + DNA ligase fill in the gap

Question 25

How do the ends of DNA extend?

Answer 25

with non-coding repeating sequences called Telomeres

Question 26

Telomeres do what?

Answer 26

repeat sequences at the ends of the DNA
strands that protect the DNA from shortening

Question 27

Telomerase does what?

Answer 27

protect the DNA from shortening

Question 28

Order of DNA packaging and organizing (5)

Answer 28

DNA
Histones
Nucleosomes
Chromatin fibers
Chromosomes

Question 29

What is the Polymerase Chain Reaction?

Answer 29

Amplifyes copies of DNA sequence

Question 30

What is DNA sequencing?

Answer 30

Determines the order of the NTPs, dNTPs, ddNTPs

Question 31

What are the steps of PCR (3)

Answer 31

1) Denaturation
2) Annealing
3) Elongation

Question 32

Denaturation does what?

Answer 32

unwinding process at a high temp

Question 33

Annealing does what

Answer 33

priming process at a high temp and forming complementary pairs

Question 34

Elongation does what?

Answer 34

RNA polymerase elongates the RNA
polynucleotide in 5’–>3’ directions

Question 35

What are the requirements of PCR (4)

Answer 35

-Thermus aquaticus (Taq) polymerase – catalyzes
reaction at a higher temperature
– MgCl2
– dNTPs
– Template