Download Central Dogma Activity KEY DNA Replication Analysis Questions

Central Dogma Activity KEY
DNA Replication Analysis Questions
1. Record the sequence of bases for your Template DNA Strand and the Complementary DNA Strand on your
answer sheet.
Depends on the DNA number you have:
#1
#2
#3
#4
2. What kinds of bonds form between the bases of the original and new strands of DNA?
Hydrogen bonds
3. What three types of molecules make up a DNA molecule (be specific to DNA)?
Sugar (deoxyribose), Phosphate group, Nitrogenous base (Adenine, Thymine, Cytosine, & Guanine)
4. What does “complementary” mean?
In terms of base pairs it means that the bases match up in certain pairs. A always binds with T and C always
binds with G.
5. What is it called when the replicated DNA molecule is made up of one old and one new strand?
Semi-conservative
Transcription Analysis Questions
1. Record the sequences of bases in your mRNA molecule.
Depends on the original DNA number you have:
#1
#2
#3
#4
2. What molecules make up RNA?
Sugar (ribose), Phosphate group, Nitrogenous base (Adenine, Uracil, Cytosine, & Guanine)
3. How many types of RNA exist? Name each type of RNA
3 types of RNA: mRNA (messenger), tRNA (transfer), rRNA (ribosomal)
4. List 3 major structural differences between RNA and DNA.
They have different sugars (ribose vs. deoxyribose), DNA is double stranded while RNA is single stranded,
and DNA has thymine while RNA has uracil instead
5. What is the main objective of transcription?
Transcription converts a gene from DNA into a complementary single-stranded RNA sequence (either mRNA,
tRNA, or rRNA…typically we focus on mRNA)
6. Where does transcription take place?
Within the nucleus
7. What is RNA polymerase? What does it do?
RNA polymerase is an enzyme that does two jobs (1) unzips and unwinds a segment of DNA and (2) adds the
complementary RNA nucleotides to make the RNA strand
8. What is the purpose of mRNA?
mRNA carries the message from the DNA to outside the nucleus on a ribosome where it will be used during
translation (to code for the amino acids that make up a protein).
9. How does mRNA get out of this organelle?
mRNA is small enough to leave through the nuclear pores within the nuclear envelope
10. What do we call a sequence of 3 mRNA bases that code for an amino acid?
Codon
Translation Analysis Questions
1. What is the difference between transcription and translation?
Transcription uses DNA to create a complementary RNA strand within the nucleus, translation occurs outside
the nucleus (on a ribosome) and uses the mRNA message to code for amino acids to make up a protein
2. What is the purpose of the tRNA?
tRNA transports the correct amino acid to the ribosome to add it to the growing polypeptide (protein) chain
3. On which type of RNA is the codon located? Which type of RNA is the anticodon located?
mRNA contains the codon and tRNA has the anticodon that is complementary to the codon
4. Does the codon or the anticodon code for the amino acids? What does the other one do?
5. The codon codes for the amino acid, the anticodon helps direct the tRNA where to go so it brings the correct
amino acid (based on the codon!)
6. What sequence codes for the amino acid valine?
GUU, GUC, GUA, GUG
7. What amino acid is brought in by the codon AGA?
Arginine (Arg)
8. What does rRNA do? How does the rRNA know where to start reading and where to stop reading the mRNA?
rRNA makes up part of the ribosome. The start codon signals for the beginning of the protein chain and the
stop codon signals for when the chain of amino acids is complete.
9. On what organelle does translation take place? Do these organelles have membranes?
Translation occurs on the ribosome. These organelles do not have membranes.
10. Which type of cells, eukaryotic and/or prokaryotic, have these organelles?
BOTH prokaryotic cells and eukaryotic cells have ribosomes.
Mutations Analysis Questions
1. What is a mutation?
A mutation is a change in an organism’s DNA
2. What causes mutation (in a general sense)?
They can happen spontaneously or be induced (by things like certain types of radiation including UV light and
X-rays, or chemicals like benzene in cigarettes, or by viruses)
3. What kind of mistake(s) can happen during DNA replication?
A nucleotide could be replaced for a different one (point mutation such as silent, missense or nonsense) or a
nucleotide could be added in or deleted causing a frameshift mutation
4. Why could changing one nucleotide cause a mutation?
If you change a nucleotide you change the sequence of DNA. It could affect one or more amino acids (either
coding for different ones or making a stop codon or changing a stop codon to an amino acid) which could
affect whether the protein functions properly or not.
5. How does a misplaced stop codon due to mutation influence translation?
It could either stop the chain too early or it could make it so the chain is too long – either way it most likely
will affect the function of the protein.
6. Compare the original and mutated amino acid sequences; how do the sequences compare and what changes
have occurred?
Due to the mutations there are several changes between the two chains: