Name _________________________________________________
Chapter 12 Review Sheet
1. Know the components and structure of DNA
o What makes up the sides (backbone) of the DNA ladder? _deoxyribose__ &
__phosphate__
o What makes up the rungs of the DNA ladder? _nirtogen bases
o What type of chemical bond holds the two strands of DNA together? __hydrogen_
2. Identify & Label the three parts of a nucleotide. _nitrogen base____, _deoxyribose_____, &
_phosphate____
3. What are the 4 types of nitrogen bases found in DNA? __adenine______, _guanine__,
_cytosine______, ____thymine________
4. What are the nitrogen base pairing rules?
_A___ bonds with _T____ & ____C___ bonds with __G____
5. Know the following individuals and their contributions to the discovery of DNA as genetic
material: Frederick Griffith, Oswald Avery, Hershey & Chase, Erwin Chargaff, Rosalind
Franklin, James Watson, and Francis Crick
o Which individual discovered transformation? __________Griffith_______
o Which individual followed up Griffith’s work to conclude DNA was the transforming
factor and DNA is indeed the genetic information?
____Avery___________
o Which individuals used radioactive labels on bacteriophage to prove that DNA is the
genetic material? ___Hershey and Chase_______
o Which individual took a picture of DNA using x-ray diffraction? __Franklin_____
o Which individuals discovered the structure of DNA and named their model the “double
helix”? ___Watson_____ & ____Crick_____
o Which individual discovered the nitrogen base pairing rules? _Chargaff______
6. Chromosome Packaging
o In order for DNA to fit into the nucleus, DNA winds around proteins called
__Histones____
o Uncoiled DNA is known as __chromatin______
o Eventually chromatin will supercoil into these X-shaped structures called
__chrmomosomes_______
7. Understand how DNA is replicated
o What enzyme unzips DNA? ___Helicase________
o The Y-shaped structure where the DNA double helix is unwound during DNA replication
is called the ____Replication Fork___________
o What enzyme adds complimentary base pairs and proofreads DNA? __DNA
Polymerase_______
o A __gene_______ is a segment of DNA that codes for a specific protein.
o During DNA replication, a DNA strand that has the bases ATCGTA produces a strand
with the bases _____TAGCAT_______.
8. Distinguish between DNA and RNA in terms of structure and function.
Statement
DNA
1. Contains ribose sugar
2. Double stranded
RNA
x
x
3. Contains deoxyribose sugar x
4. Contains uracil
x
5. Contains thymine
x
6. Single stranded
x
9. Identify the three types of RNA and explain their functions.
RNA Type
Function
mRNA
Copies DNA during transcription in nucleus
rRNA
Makes up the ribosome
tRNA
Carries amino acid to the ribosome during translation
Label the different types of RNA.
__rRNA____
_tRNA_
__mRNA_____
10. Describe the process of transcription
o Where does transcription take place in a eukaryotic cell? __nucleus___
o What is the area on DNA where transcription begins? ____promoter_____________
o What enzyme is involved in transcription? _____RNA polymerase______
o Transcribe the following DNA sequence:
DNA - T A C G G G C G C T T T A C A A C T
mRNA- _ATG
CCC
GCG
AAA UGU UGA_
11. RNA Editing
o The sections of mRNA that are removed are ___intron__________.
o The necessary sections of mRNA that are kept in the mRNA are called
____exons_________.
o
12. Describe the process of translation
o Where does translation take place in a eukaryotic cell? ___cytoplasm/ribosome______
What happens during the process of translation?
a.
b.
c.
d.
Messenger RNA is made from DNA.
Messenger RNA is read to produce proteins.
Transfer RNA is made from messenger RNA.
Copies of DNA molecules are made.
o What structure in the cell are proteins made (Hint: rRNA makes this structure)?
__ribosome___
o What is a codon? What is each a code for? 3 letter code, one amino acid
o ___Methionine________ is the amino acid that begins all protein chains.
13. Use your codon wheels to answer the following questions:
___ According to the wheel above, what codon specifies the amino acid arginine?
a. GA
b. AGGA
c. AGG
d. UCC
___ According to the wheel above, what codon specifies the amino acid proline ?
a. ACU
b. UGA
c. AA
d. CCC
o Using the codon wheel list the possible codons that code for the amino acid Lysine.
AAA, AAG
o Three bases on tRNA are called ___anti-codon___________.
o If a codon is UAC. What is the anti-codon sequence ? __AUG_
o A chain of amino acids are called a _polypeptide/protein______.
o The genetic code of DNA is carried to the ribosomes by __mRNA________.
o The part of tRNA that is complement of the mRNA codon is the _anti-codon_______.
14. First, Transcribe the DNA into mRNA and then Translate the mRNA into an amino acid (A.A.)
sequence.
DNA:
TAC CGG TTA CCC GAT CTA TTA CGG ATC
mRNA: __AUG GCC AAU GGG CUA GAU AAU GCC UAG___
A. A. : __Met- Ala- Asp- Gly- Leu- Asp acid- Asp-Ala- STOP_______