Chapter 8 Study Guide
Name:__________________________________ Date:___________________ Period:__________
1. What are the two types of nucleic acid? How are they similar? How are they different?
-DNA and RNA.
-They are both nucleic acids, and are made up of the monomer nucleotides. Both contain a sugar,
phosphate and 4 different nitrogen bases.
-DNA is double stranded and in the shape of a helix. The sugar is Deoxyribose. DNA has the nitrogen
base Thymine.
RNA is single stranded. The sugar is Ribose. RNA has the nitrogen base Uracil.
2. What did each of the following scientists do help our understanding of DNA?
A. Frederick Griffith-Experimented on mice with two forms of bacteria (smooth and rough) that caused
pneumonia. His experiment demonstrated Transformation. He called the factor that changed the
bacteria the “transforming principal.”
B. Oswald Avery-Continued to work on Griffith’s experiment. He determined that DNA is the source of
genetic information.
C. Hershey and Chase-Used bacteriophage infected with radioactivity to support the idea of DNA being
genetic material.
D. Watson and Crick- Use the x-rays of Franklin to identify the shape of DNA (double helix)
E. Charfaff- Complementary base paring for DNA (A-T, G-C)
3. What does DNA stand for? Deoxyribo Nucleic Acid
4. What is the monomer of DNA? Nucleotide
5. Draw and label a DNA nucleotide.
6. What are the four nitrogen bases for DNA and how do they differ? Adenine (A) Guanine (G) Cytosine (C)
Thymine (T). They differ in size and shape.
7. Define Complementary base paring.
-The nitrogen base on one side of the ladder ALWAYS pair up with the same nitrogen base on the other side
of the ladder (A-T, G-C).
8. Describe the structure of DNA. Draw and label a picture of DNA. Include the following: sugar, phosphate,
nitrogen base backbone rungs, and box a nucleotide.
DNA is a double stranded and is shaped like a spiral ladder. It consists of phosphate, Deoxyribose, and
nitrogen base. The phosphate and sugar makes up the sides, or backbone, of DNA. The four nitrogen bases,
or rungs of the ladder, are Adenine, Guanine, Cytosine, and Thymine. The nitrogen bases are held together
by a hydrogen bond.
9. What is DNA replication and why is it important? Where does DNA replication? When does DNA replication
take place?
-Replication is the process of making a duplicate strand of DNA. It is an exact copy of DNA. It is important
because DNA must replicate in order for your body cells to replicate and divide with equal genetic material.
-DNA replication takes place in the nucleus.
-DNA replication takes place during the S-phase of interphase
10. Describe the three steps in DNA replication.
1. Helicase (an enzyme) unzips the DNA helix.
2. DNA polymerase (another enzyme) attaches to each strand of the DNA and moves along the strand
adding complementary base pairs. It will do so until the DNA molecule has been fully replicated.
3. Both molecules rewind and the result is two identical DNA molecules.
11. What is DNA polymerase? What is its role in DNA replication?
DNA polymerase in an enzyme that attaches to the DNA strand and adds complementary base pairs during
DNA replication.
12. How many copies of DNA are there after DNA replication? Two. Each DNA molecule is made up of one
original strand and one new strand.
13. What does it mean when it is said “DNA is used as its own template” in DNA replication?
The original DNA strand is unzipped by helicase. DNA polymerase is used to add complementary nitrogen
bases to both sides of the original strand. This creates two exact copies of the DNA.
14. Complete the complementary stands of DNA based off of the given original strands.
A. Original: ATTCGCTA
Compliment: TAAGCGAT
B. Original: CCGATTGA
Compliment: GGCTAACT
C. Original: TATTACGC
Compliment: ATAATGCG
15. What are the three parts of the Central Dogma?
DNARNAProtein
16. What does RNA stand for? What is the monomer of RNA?
Ribo Nucleic Acid. Nucleotides.
17. What are the four nitrogen bases for RNA? How do they pair up?
Adenine (A) Guanine (G) Cytosine (C) Uracil (U). (A-U, G-C)
18. Draw an RNA nucleotide; include the nitrogen base that is not found in DNA.
19. What is RNA polymerase? How is it different from DNA polymerase?
RNA polymerase is an enzyme that adds complementary RNA base pairs by using DNA as a template. It
differs from DNA polymerase because it adds Uracil instead of Thymine.
20. What does Transcription make?
Transcription makes an RNA molecule from the DNA molecule.
21. Describe the four steps of Transcription. Where does Transcription take place?
Transcription takes place in the nucleus because DNA is too big to fit through the nuclear pores. mRNA is made
from the code of DNA.
1. DNA unwinds.
2. RNA Polymerase binds to DNA
3. It adds complementary RNA nucleotides (U↔A) C-G
4. RNA Polymerase releases DNA & RNA molecules.
22. Describe the 6 steps of Translation. Where does Translation take place.
Translation takes place in the cytoplasm. RNA makes protein.
1. mRNA leaves nucleus
2. Ribosome attaches to mRNA start codon - AUG
3. mRNA codon pairs with tRNA delivering amino acid
4. mRNA stop codon signals end of translation (UAA, UAG, UGA). The ribosome releases the newly formed
polypeptide
6. mRNA released & polypeptide complete
23. What does Translation make?
Translation makes protein from an mRNA template.
24. What is the role of the enzyme helicase?
Helicase is an enzyme that “unzips” the DNA molecule at the hydrogen bonds on the nitrogen bases.
25. What are the three types of RNA and what do they do?
mRNA – made during transcription. It is carrying the message or code from DNA.
rRNA – the ribosome structure that contains the mRNA.
tRNA – translate the mRNA into specific amino acids which will code for specific enzymes.
26. Where do replication, transcription and translation take place in the cell?
Replication and Transcription take place in the nucleus. Translation takes place in the cytoplasm.
27. Give the RNA sequence for the following DNA sequence.
A. DNA: ATTCGCTA
RNA: UAAGCGAU
B. DNA: CCGATTGA
RNA: GGCUAACU
C. DNA: TATTACGC
RNA: AUAAUGCG
28. Define codon.
A codon is a set of three base pairs of mRNA that code for a specific amino acid attached to the tRNA.
29. Using the genetic code, what do the following codons code for?
*Need to use the chart from your notes*
A. UCC: Serine
B. GCG: Arginine
C. GUA: Valine
D. AAA: Lysine
30. What is the start codon? What does it code for?
AUG: Methionine
31. What are the two types of mutations?
Sex cell mutations and Body cell mutations.
32. Describe substitution, deletion and insertion.
Substitution: One nitrogen base is substituted by another nitrogen base resulting in a new codon and
amino acid. Considered a Point mutation.
Deletion: A nitrogen base is deleted, causing a frame shift and changes the sequence of amino acids.
Insertion: A nitrogen base is inserted, causing a frame shift and changes to the sequence of amino acids.
33. What do sex cell mutations affect? Body cell mutations?
Sex cell mutations affect offspring. Body cell mutations affect the individual only.
34. Label the following diagrams.
X-Nucleotide
A. original DNA strand
A- rRNA
B- tRNA
C-mRNA
B. new DNA strand
C. phosphate/sugar backbone
D. mRNA strand
E. start codon
F. codon
X. transcription
Y. translation
What process does the diagram below depict? DNA Replication