MMBIO 240 Exam 2 Poole (MMBIO 240 BYU Dr. Poole Ch.
10-14) Question With Complete Solutions
30nm Filament Correct Answers Created by use of H1 and N-
terminal histone tails holding DNA more tightly to histone,
tightly condenses DNA
Alkylation damage Correct Answers Adds hydrophobic groups
(hydrocarbons) to DNA which blocks hydrogen bonds between
base pairs
Cigarette smoke and Aflatoxin (peanut)
Base Excision Repair Correct Answers Used to fix SMALL
DAMAGE to single bases (oxidative, small alkylations, apurinic
sites, water damage). Steps:
1) Base is cut off backbone with glycosylase
2) Backbone is nicked by AP endonuclease
3) Polymerase 1 inserts one or a few nucelotides
4) Flap endonuclease removes a few nucleotides
5) Ligase seals nick (small gap)
Carcinogenesis Correct Answers enough mutation to become
cancerous
Chemotherapeutic Agents Correct Answers Targets DNA
replication proteins to kill cancerous cells before healthy cells
are killed
Cisplatin: causes cross-links
Bleomycin: Forms reactive oxygen species which breaks strands
Doxorubicin: Blocks replication forks
, Chromosome Correct Answers 1400nm
Common Transposons Correct Answers Cut & Paste (Non-Rep)
Transposition, Replicative Transposition, Retrotransposition
(LTR and non-LTR), Bacterial Transposons, Eukaryotic
Transposons
Compare LTRs, non-LTRs, and retroviruses: Correct Answers
LTR Retrotransposons
-Long Terminal Repeat (LTR)
-Prime for reverse transcriptase is tRNA
-Integrase inserts DNA into target site
Non-LTR Retrotransposons
-Don't have an LTR
-Enzyme brings RNA to target site and then cuts one target
strand
-Uses the cut strand as primer for reverse transcriptase
-Inserts the DNA copy into DNA
-SINEs (short) can still transpose by hijacking the functional
transposase
-LINEs (long) Functional transposase, one LINE can activate
many SINEs from having functional transposase that the SINEs
hijack
-SINEs are defective LINEs
Retroviruses
-Similar to Retrotransposons, except they have an additional
"envelope gene"
Core Histones Correct Answers H2A
10-14) Question With Complete Solutions
30nm Filament Correct Answers Created by use of H1 and N-
terminal histone tails holding DNA more tightly to histone,
tightly condenses DNA
Alkylation damage Correct Answers Adds hydrophobic groups
(hydrocarbons) to DNA which blocks hydrogen bonds between
base pairs
Cigarette smoke and Aflatoxin (peanut)
Base Excision Repair Correct Answers Used to fix SMALL
DAMAGE to single bases (oxidative, small alkylations, apurinic
sites, water damage). Steps:
1) Base is cut off backbone with glycosylase
2) Backbone is nicked by AP endonuclease
3) Polymerase 1 inserts one or a few nucelotides
4) Flap endonuclease removes a few nucleotides
5) Ligase seals nick (small gap)
Carcinogenesis Correct Answers enough mutation to become
cancerous
Chemotherapeutic Agents Correct Answers Targets DNA
replication proteins to kill cancerous cells before healthy cells
are killed
Cisplatin: causes cross-links
Bleomycin: Forms reactive oxygen species which breaks strands
Doxorubicin: Blocks replication forks
, Chromosome Correct Answers 1400nm
Common Transposons Correct Answers Cut & Paste (Non-Rep)
Transposition, Replicative Transposition, Retrotransposition
(LTR and non-LTR), Bacterial Transposons, Eukaryotic
Transposons
Compare LTRs, non-LTRs, and retroviruses: Correct Answers
LTR Retrotransposons
-Long Terminal Repeat (LTR)
-Prime for reverse transcriptase is tRNA
-Integrase inserts DNA into target site
Non-LTR Retrotransposons
-Don't have an LTR
-Enzyme brings RNA to target site and then cuts one target
strand
-Uses the cut strand as primer for reverse transcriptase
-Inserts the DNA copy into DNA
-SINEs (short) can still transpose by hijacking the functional
transposase
-LINEs (long) Functional transposase, one LINE can activate
many SINEs from having functional transposase that the SINEs
hijack
-SINEs are defective LINEs
Retroviruses
-Similar to Retrotransposons, except they have an additional
"envelope gene"
Core Histones Correct Answers H2A
