MOLECULAR BIOLOGY OF THE CELL 7TH
EDITION FINAL PAPER 2026 COMPLETE
SOLUTIONS AND CORRECT ANSWERS
GRADED A+
⩥ Chromosome mutations. Answer: Affects the structures of the entire
chr, requires the movement of large chr regions
⩥ Genome mutations. Answer: Change in the number of chr's
⩥ Eupliod. Answer: normal complement of chromosomes
⩥ Aneuploid. Answer: Increased number of chr's (eg. Down's syndrome)
⩥ Haploid. Answer: Single copy of each chr (humans have 23)
⩥ Diploid. Answer: Two copies of each chr (humans have 46)
⩥ DNA polymerase. Answer: Catalyzes phosphodiester bond between
nt's
Uses ssDNA as a template to determine which nt's to add
,⩥ DNA Polymerase I (Prok). Answer: Processes Okazaki fragments
Replaces RNA primers with DNA (exonuclease activity)
Excision repair & proof reading
⩥ DNA Polymerase II (Prok). Answer: DNA repair, exonuclease activity
⩥ DNA Polymerase III (Prok). Answer: Primary enzyme involved in
replication
Exonuclease activity
⩥ DNA Polymerase IV (Prok). Answer: Bypass replication
SOS response
⩥ DNA Polymerase V (Prok). Answer: Bypass replication
SOS response
Translesion synthesis DNA repair
⩥ DNA Polymerase α (Euk). Answer: Primase
DNA dependent DNA & RNA pol
⩥ DNA Polymerase β (Euk). Answer: Base excision repair (BER)
,⩥ DNA Polymerase δ (Euk). Answer: Lagging strand synthesis
DNA repair, exonuclease, replaces primers as it encounters Okazaki
fragments
⩥ DNA Polymerase ε (Euk). Answer: Leading strand synthesis
exonuclease
⩥ DNA Polymerase γ (Euk). Answer: mtDNA replication and repair
Exonuclease activity
⩥ Terminal transferase. Answer: DNApol synthesizes poly-nt chain at 3'
end w/o a template
⩥ Transcription. Answer: initiation --> elongation --> termination
⩥ Retrotransposons. Answer: Mobile genetic elements which can
increase genome size and insert itself within coding/noncoding regions
⩥ The three biochemical activities of reverse transcription. Answer:
RNA-dependent DNApol, Ribonuclease H, and DNA-dependent
DNApol --> all used to create ds cDNA from RNA
⩥ Describe the steps of reverse transctiption. Answer: 1. tRNA acts as a
primer and hybridizes to virus genome
, 2. Complementary DNA then binds to the U5 (non-coding region) and R
region
3. RNAse H degrades the 5' end of the RNA which removes the U5 and
R region.
4. The primer then "jumps" to the 3' end of the viral genome and the
newly synthesized DNA strands hybrid
⩥ Exons. Answer: Gene sequences that represent codons used in TLN to
protein
⩥ Introns. Answer: Non-coding sequences that are spliced out before
TLN
⩥ Splicing. Answer: modification of the nascent pre-messenger RNA
(pre-mRNA) transcript in which introns are removed and exons are
joined.
⩥ R-factors. Answer: resistance transfer factors. Carry antibiotic
resistance to common antibiotics.
⩥ Colicinogenic factors. Answer: resistance to bacteriocins, toxic
proteins manufactured by bacteria.
⩥ Primary protein structure. Answer: sequence of a chain of amino acids
EDITION FINAL PAPER 2026 COMPLETE
SOLUTIONS AND CORRECT ANSWERS
GRADED A+
⩥ Chromosome mutations. Answer: Affects the structures of the entire
chr, requires the movement of large chr regions
⩥ Genome mutations. Answer: Change in the number of chr's
⩥ Eupliod. Answer: normal complement of chromosomes
⩥ Aneuploid. Answer: Increased number of chr's (eg. Down's syndrome)
⩥ Haploid. Answer: Single copy of each chr (humans have 23)
⩥ Diploid. Answer: Two copies of each chr (humans have 46)
⩥ DNA polymerase. Answer: Catalyzes phosphodiester bond between
nt's
Uses ssDNA as a template to determine which nt's to add
,⩥ DNA Polymerase I (Prok). Answer: Processes Okazaki fragments
Replaces RNA primers with DNA (exonuclease activity)
Excision repair & proof reading
⩥ DNA Polymerase II (Prok). Answer: DNA repair, exonuclease activity
⩥ DNA Polymerase III (Prok). Answer: Primary enzyme involved in
replication
Exonuclease activity
⩥ DNA Polymerase IV (Prok). Answer: Bypass replication
SOS response
⩥ DNA Polymerase V (Prok). Answer: Bypass replication
SOS response
Translesion synthesis DNA repair
⩥ DNA Polymerase α (Euk). Answer: Primase
DNA dependent DNA & RNA pol
⩥ DNA Polymerase β (Euk). Answer: Base excision repair (BER)
,⩥ DNA Polymerase δ (Euk). Answer: Lagging strand synthesis
DNA repair, exonuclease, replaces primers as it encounters Okazaki
fragments
⩥ DNA Polymerase ε (Euk). Answer: Leading strand synthesis
exonuclease
⩥ DNA Polymerase γ (Euk). Answer: mtDNA replication and repair
Exonuclease activity
⩥ Terminal transferase. Answer: DNApol synthesizes poly-nt chain at 3'
end w/o a template
⩥ Transcription. Answer: initiation --> elongation --> termination
⩥ Retrotransposons. Answer: Mobile genetic elements which can
increase genome size and insert itself within coding/noncoding regions
⩥ The three biochemical activities of reverse transcription. Answer:
RNA-dependent DNApol, Ribonuclease H, and DNA-dependent
DNApol --> all used to create ds cDNA from RNA
⩥ Describe the steps of reverse transctiption. Answer: 1. tRNA acts as a
primer and hybridizes to virus genome
, 2. Complementary DNA then binds to the U5 (non-coding region) and R
region
3. RNAse H degrades the 5' end of the RNA which removes the U5 and
R region.
4. The primer then "jumps" to the 3' end of the viral genome and the
newly synthesized DNA strands hybrid
⩥ Exons. Answer: Gene sequences that represent codons used in TLN to
protein
⩥ Introns. Answer: Non-coding sequences that are spliced out before
TLN
⩥ Splicing. Answer: modification of the nascent pre-messenger RNA
(pre-mRNA) transcript in which introns are removed and exons are
joined.
⩥ R-factors. Answer: resistance transfer factors. Carry antibiotic
resistance to common antibiotics.
⩥ Colicinogenic factors. Answer: resistance to bacteriocins, toxic
proteins manufactured by bacteria.
⩥ Primary protein structure. Answer: sequence of a chain of amino acids
