DNA Replication

Question 1

Does dna make exact copies of itself

Answer 1

Yes

Question 2

Semiconservative

Answer 2

Both parental strands unchanged, child strands new.

Question 3

Sense vs antisense

Answer 3

Strand that is the same as mRNA is sense, antisense read by RNA poly

Question 4

Bacterial vs eukaryotic chromosome

Answer 4

Bacterial are circular. Eukaryotes have many replication forks, 10x slower than bacteria

Question 5

Mitochondrial dna

Answer 5

Resemble bacterial. Inherited maternally.

Question 6

Lagging strand replication

Answer 6

Makes okazaki fragments

Question 7

all polymerase rules

Answer 7

Add to 3’ hydroxyl. Cannot join 3’ to 5’

Question 8

DNA polymerase

Answer 8

Proofread, highly accurate, need primer

Question 9

RNA polymerase

Answer 9

No proofreading, make short fragments, don’t need primer

Question 10

First step in replication

Answer 10

Negative supercoiling induced by gyrase or topoisomerase. Helicase then unwinds strands. Held apart by single strand binding proteins

Question 11

Prokaryotic DNA poly

Answer 11

1-repair and gap filling
2-unknown
3- leading and lagging synthesis

Question 12

Eukaryotes dna poly

Answer 12

Alpha-early replication(primase)
Beta- repair
Gamma- mtDNA synthesis 
Delta- lagging
Epsilon- leading

Question 13

Phosphodiester bond

Answer 13

Poly forms between nucleotides, leaving only one P

Question 14

Lagging strand synthesis

Answer 14

Fragments grow from rna primers made by primase. Primers removed by poly 1 or RNase H(euk). Sealed by ligase.

Question 15

Mutation types

Answer 15

Point mutation
Transition - A for G etc. 
Transversion- A for T etc. 
translocation- segment moves
Insertion
Deletion
Inversions

Question 16

Mutation outcomes

Answer 16

Silent
Nonsense- insert stop codon
Frameshift
Missense-change one amino acid to another

Question 17

Mutation causes

Answer 17

Tautomeric shifts
Ionizing radiation
UV light(dimers, mostly T)
Chemicals(analogs, deaminating, alkylating, intercalating)

Question 18

3’ to 5’ exonuclease

Answer 18

Proofreading, backs up to fix

Question 19

5’ to 3’ exonuclease

Answer 19

Fixes damage and removed RNA primer

Question 20

DNA repair types

Answer 20

Excision- takes out piece of chain

Deamination- removes one base

Question 21

Telomeres

Answer 21

End of chromosomes. 250-1000 repeats of TTAGGG. Telomerase makes them not reduce.

Question 22

Hayflick limit

Answer 22

Telomeres too short