Genetics
Name:
State Standard:
H.1L.2 -- Describe the chemical structure of DNA and its relationship to
chromosomes. Explain the role of DNA in protein synthesis.
Score
10
Response
Excellent
8
Proficient
6
Adequate
4
Incorrect
1
Fails to complete
Mini Lab 11-2
Scoring Rubric 1-4
Responses are clear, complete and demonstrate a thorough
understanding of the subject matter
Completes the assignment or experiment satisfactorily, but
the explanations have minor flaws
Begins the assignment and explanation satisfactorily; but
omits significant parts or fails to complete.
Assignment and its explanations are not accurate. Group did
not demonstrate understanding or authentic knowledge
Fails to complete
Gene Mutations and Proteins
Gene Mutations often have serious effects on proteins. In this activity, you will demonstrate how such
mutations affect protein synthesis.
Procedure:
1. Use the following base sequence of one strand of an imaginary DNA molecule.
Write the base sequence for an mRNA strand that would be transcribed from the given DNA
sequence. AAT GCC AGT GGT TCG CAC.
2. Use table 11.2 to determine the sequence of amino acids in the resulting protein fragment.
3. If the fourth base in the original DNA strand were changed from G to C, how would this affect
the resulting protein fragment?
4. If a G were added to the original DNA strand after the third base, what would the resulting
mRNA look like? How would this addition affect the protein.
Analysis:
Which change in DNA was a point mutation? Which was a frame shift mutation?
In what way did the point mutation affect the protein?
How did the frame shift mutation affect the protein?
TRANSCRIBE AND TRANSLATE
Name
Mini-lab 11.1
Molecules of DNA carry the genetic instructions for protein formation. Converting these DNA
instructions into proteins requires a series of coordinated steps in transcription and translation.
Procedure:
1. Use the data table below. Complete column B by writing the correct mRNA codon for each
sequence of DNA bases listed in the column marked DNA Base Sequence. Use the letters A, U, C, G.
2. Identify the process responsible by writing its name on the arrow in column A.
3. Complete column D by writing the correct anitcodon that bonds to each codon from column B.
4. Identify the process responsible by writing its name on the arrow in column C.
5. Complete column E by writing the name of the correct amino acid that is coded by each base
sequence. Use table 11.2 on page 298 of your text (or your ch. 11 notes) to translate the mRNA base
sequences to amino acids.
DNA base
sequence
A
Process
B
mRNA
codon
C
Process
D
tRNA
anticodon
E
Amino Acid
AAT
GGG
ATA
AAA
GTT
Analysis
1. Where within the cell:
a. are the DNA instructions located?
b. does transcription occur?
c. does translation occur?
2. Describe the structure of a tRNA molecule.
3. Explain why specific base pairing is essential to the processes of transcription and translation.