Molecular Genetics Study Guide Exam Questions
with Correct Answers
1. List the 3 parts of a DNA nucleotide. correct answers: DNA nucleotide contains
correct answers:
1) sugar
2) phosphate group
3) Nitrogenous base
2. Which molecules make up the edges (sides) of the DNA double helix and
which molecules make up the steps? correct answers: The sides are made up of sugar
and phosphate groups. The steps are made of paired bases which are hydrogen bonded together.
3. What does semi-conservative replication mean? correct answers: Semi-conservative
replication means each new DNA molecule includes 1 edge from the old DNA molecule and one new
edge.
4. Explain how DNA replication works. Which enzyme builds the new edges?
Where does DNA replication occur? correct answers: DNA replication is the process where
DNA makes an identical copy of itself. The enzymes which builds the new edges is called a DNA
polymerase. DNA unzips and nucleotides attaches to the edges. DNA replication takes place in the cell
nuclues.
5. List 3 differences between RNA and DNA correct answers: 1) There are many types of
RNA and each type has a ditterent shape.
2) RNA has the base Uracil instead of Thymine. Instead of Thymine, Uracil bonds with Adenine in RNA, U-A,
A-U
3) The nucleotides of RNA have ribose as a sugar instead of deoxyribose.
6. Where does transcription occur? Explain the process. Which enzyme
builds the RNA strand? correct answers: Transcription occurs in the nucleus. The process where
RNA is copied from DNA- the enzyme RNA polymerase builds the RNA. The DNA bubbles and free RNA
nucleotides attach to one edge of the DNA and forms long strands of RNA which leaves the nucleus.
7. Where does translation occur? correct answers: Translation occurs at ribosomes within
the cytoplasm.
8. Explain the function of mRNA in translation. What is a codon? correct
answers: Takes the genetic
messenger out of the nuclues and into the cytoplasm. Every 3 bases of mRNA is called a codon.
1/
4
with Correct Answers
1. List the 3 parts of a DNA nucleotide. correct answers: DNA nucleotide contains
correct answers:
1) sugar
2) phosphate group
3) Nitrogenous base
2. Which molecules make up the edges (sides) of the DNA double helix and
which molecules make up the steps? correct answers: The sides are made up of sugar
and phosphate groups. The steps are made of paired bases which are hydrogen bonded together.
3. What does semi-conservative replication mean? correct answers: Semi-conservative
replication means each new DNA molecule includes 1 edge from the old DNA molecule and one new
edge.
4. Explain how DNA replication works. Which enzyme builds the new edges?
Where does DNA replication occur? correct answers: DNA replication is the process where
DNA makes an identical copy of itself. The enzymes which builds the new edges is called a DNA
polymerase. DNA unzips and nucleotides attaches to the edges. DNA replication takes place in the cell
nuclues.
5. List 3 differences between RNA and DNA correct answers: 1) There are many types of
RNA and each type has a ditterent shape.
2) RNA has the base Uracil instead of Thymine. Instead of Thymine, Uracil bonds with Adenine in RNA, U-A,
A-U
3) The nucleotides of RNA have ribose as a sugar instead of deoxyribose.
6. Where does transcription occur? Explain the process. Which enzyme
builds the RNA strand? correct answers: Transcription occurs in the nucleus. The process where
RNA is copied from DNA- the enzyme RNA polymerase builds the RNA. The DNA bubbles and free RNA
nucleotides attach to one edge of the DNA and forms long strands of RNA which leaves the nucleus.
7. Where does translation occur? correct answers: Translation occurs at ribosomes within
the cytoplasm.
8. Explain the function of mRNA in translation. What is a codon? correct
answers: Takes the genetic
messenger out of the nuclues and into the cytoplasm. Every 3 bases of mRNA is called a codon.
1/
4
