GENETICS FINAL EXAM 2026 PRACTICE
QUESTIONS AND ANSWERS TOP REVIEW A+
◉ What happens during Meiosis 2? Answer: 1. Independent
segregation of sister chromatids.
2. Each cell divides again, producing 4 haploid cells.
◉ What are the three theories of DNA Replication? Answer: semi-
conservative(parent strands split and are used as templates for new
DNA + it binds to the new DNA), conservative(parents split to make
new strands and then rejoin with each other), dispersive(old and
new DNA strands randomly join together
◉ What did the Meselson-Stahl experiment suggest was the correct
theory of DNA Replication? Answer: semi-conservative
◉ Describe the Meselson-Stahl experiment Answer: 1. Bacteria were
grown in a medium containing heavy isotope 15N for many
generations.
2. Some bacteria were moved to a medium containing light isotope
14N. Samples were extracted after 1 & 2 cycles of DNA replication.
3. Centrifugation formed a pellet. Heavier DNA (bases made from
15N) settled closer to bottom of tube.
,◉ What are the 8 ingredients needed for DNA replication? Answer:
Template DNA, Single-Strand Binding and Initiator Proteins,
Helicase, Gyrase, nucelotide precursor, Primase and Primer, DNA
Polymerase I, II, III, and DNA Ligase
◉ What end of a DNA strand are new base pairs added? Answer: 3';
bases added at the 3' end
◉ What are the three stages of DNA Replication? Answer: 1.
Initiation
2. Elongation
3. Termination
◉ What happens during the initiation stage of DNA replication in
prokaryotes? Answer: initiator proteins are added, helicase attaches
to the strand, helicase unwinds DNA strand to form replication fork,
DNA primase adds RNA primers, Single-stranded binding proteins
bind onto the unwound strands to prevent the strands from
rejoining
◉ What happens during the elongation stage of DNA replication in
prokaryotes? Answer: DNA Polymerase 3 adds new nucleotides
(DNTPs) to the 3' end of both strands
, ◉ What are the differences between the leading and lagging strands
during DNA replication in prokaryotes? Answer: The leading strand
undergoes continuous synthesis while the lagging strand undergoes
discontinuous synthesis (Synthesis of the lagging strand has to be
discontinuous because DNA polymerase cannot make a new strand
in the 3' to 5' direction. Therefore, a series of Okazaki fragments,
each with their own RNA primer, must be made as to the fork
advances)
◉ What are Okazaki fragments? Answer: Relatively short fragment
of DNA synthesized on the lagging strand during DNA replication
◉ What enzyme relieves the tension caused by the discontinuous
synthesis of the lagging strand? Answer: Topoisomerase
◉ What happens during the termination stage of DNA replication in
prokaryotes? Answer: DNA Polymerase 3 dissociates, DNA
Polymerase 1 removes RNA primers in a 5'-3' direction and replace
the primers with DNA, DNA Ligase seals the strand and repairs any
nicks left by the RNA primers
◉ What is the difference between prokaryotic and eukaryotic DNA
Answer: prokaryotic DNA is small and circular
eukaryotic DNA is long and linear
QUESTIONS AND ANSWERS TOP REVIEW A+
◉ What happens during Meiosis 2? Answer: 1. Independent
segregation of sister chromatids.
2. Each cell divides again, producing 4 haploid cells.
◉ What are the three theories of DNA Replication? Answer: semi-
conservative(parent strands split and are used as templates for new
DNA + it binds to the new DNA), conservative(parents split to make
new strands and then rejoin with each other), dispersive(old and
new DNA strands randomly join together
◉ What did the Meselson-Stahl experiment suggest was the correct
theory of DNA Replication? Answer: semi-conservative
◉ Describe the Meselson-Stahl experiment Answer: 1. Bacteria were
grown in a medium containing heavy isotope 15N for many
generations.
2. Some bacteria were moved to a medium containing light isotope
14N. Samples were extracted after 1 & 2 cycles of DNA replication.
3. Centrifugation formed a pellet. Heavier DNA (bases made from
15N) settled closer to bottom of tube.
,◉ What are the 8 ingredients needed for DNA replication? Answer:
Template DNA, Single-Strand Binding and Initiator Proteins,
Helicase, Gyrase, nucelotide precursor, Primase and Primer, DNA
Polymerase I, II, III, and DNA Ligase
◉ What end of a DNA strand are new base pairs added? Answer: 3';
bases added at the 3' end
◉ What are the three stages of DNA Replication? Answer: 1.
Initiation
2. Elongation
3. Termination
◉ What happens during the initiation stage of DNA replication in
prokaryotes? Answer: initiator proteins are added, helicase attaches
to the strand, helicase unwinds DNA strand to form replication fork,
DNA primase adds RNA primers, Single-stranded binding proteins
bind onto the unwound strands to prevent the strands from
rejoining
◉ What happens during the elongation stage of DNA replication in
prokaryotes? Answer: DNA Polymerase 3 adds new nucleotides
(DNTPs) to the 3' end of both strands
, ◉ What are the differences between the leading and lagging strands
during DNA replication in prokaryotes? Answer: The leading strand
undergoes continuous synthesis while the lagging strand undergoes
discontinuous synthesis (Synthesis of the lagging strand has to be
discontinuous because DNA polymerase cannot make a new strand
in the 3' to 5' direction. Therefore, a series of Okazaki fragments,
each with their own RNA primer, must be made as to the fork
advances)
◉ What are Okazaki fragments? Answer: Relatively short fragment
of DNA synthesized on the lagging strand during DNA replication
◉ What enzyme relieves the tension caused by the discontinuous
synthesis of the lagging strand? Answer: Topoisomerase
◉ What happens during the termination stage of DNA replication in
prokaryotes? Answer: DNA Polymerase 3 dissociates, DNA
Polymerase 1 removes RNA primers in a 5'-3' direction and replace
the primers with DNA, DNA Ligase seals the strand and repairs any
nicks left by the RNA primers
◉ What is the difference between prokaryotic and eukaryotic DNA
Answer: prokaryotic DNA is small and circular
eukaryotic DNA is long and linear
