Download Biology 12 Name: DNA Functions Practice Exam A. DNA Structure 1

Biology 12
Name:
DNA Functions Practice Exam
A. DNA Structure
1. DNA is often called the "code of life". Actually it contains the code for
a) the sequence of amino acids in a protein
b) the sequence of base pairs
c) producing mutations
d) making a recipe
2.
Describe (draw) the structure of a chromosome. Identify: DNA, proteins + a gene.
3.
One nucleotide of DNA is made of three smaller parts. What are these parts?
4.
What are the full names of the bases found in DNA? Which ones bond with each other?
5.
Fill in the following chart that compares DNA and RNA:
DNA
RNA
# of strands
type of sugar
location in
cell
bases
types
6.
A sample of DNA was analyzed and scientists found that 32% of the nitrogenous bases were guanine.
What percentage of the following bases would also be in the sample?
Thymine:
Cytosine:
Uracil:
Adenine:
B. DNA Replication
7. a. What is the result of DNA replication?
b. Where in the cell does DNA replication occur?
c. Why does DNA replication occur before cell division?
d. Why is cell division an important cell process?
8.
a)
Name the molecule indicated by X.
b) Where in a human cell does the process shown above occur?
c)
List three functions of molecule X.
Protein Synthesis
9. Give one role of each of the following in the production of a protein.
a) DNA
b) mRNA
c)
tRNA
d) rRNA
10.
Reading from left to right, from the DNA sequence:
TACAAGATT
a)
What is the importance of the codon transcribed at the end of this sequence?
b) What would be the corresponding tRNA bases found on the anticodons?
c)
Which amino acids would be coded for if cytosine was deleted from the DNA sequence?
11. Complete the following chart contrasting the two parts of protein synthesis:
Transcription
Translation
Location in cell where
it occurs
Types of RNA
associated with this
Product
12.
What is the name of the structure that
a)
carries amino acids to the ribosome?
b) forms between adjacent amino acids?
c)
is the original instructions for a protein?
d) contains a series of codons?
e)
is the site of translation?
13. Use the following DNA sequence to answer the questions below:
TAACCGGATAGTCTAATT
a)
What is the mRNA sequence that would be transcribed from the DNA above?
b) Use your chart of mRNA codons to list the 6 amino acids in the sequence.
c)
What type of bond would join these amino acids together?
d) What would be the sequence of bases (letters) on the tRNA anticodons that would bring the above
amino acids to the ribosome?
14. How many amino acids will be in a polypeptide with the following DNA sequence:
ATTGCCATGACAATAGGCATAAACAGGTCA
15. Which of the following best describes the function of mRNA?
a)
it stays in the nucleus and is copied by DNA
b)
it carries amino acids to the growing polypeptide chain
c)
it makes up the ribosomes and provides the site for protein synthesis
d)
it is transcribed from the DNA and carries the information to the ribosome
16. Read the following DNA sequence left to right:
TATCTT
a.
What will be the correct mRNA sequence?
b.
What will be the correct amino acid sequence?
17. Using the table of codons, determine the sequence of amino acids coded for by this mRNA sequence:
C-U-C-C-G-A-U-A-C
Amino acid sequence:
18. The role of ribosomes in protein synthesis is to
a) split the two strands of DNA apart.
b) check for and replace faulty codons.
c) carry amino acids to the site of translation.
d) provide a site for mRNA and tRNA to join together.
19. What is the DNA sequence that would produce the following amino acid strand:
alanine – methionine – alanine
a)
b)
c)
d)
GCAAUGGCG
GCGAUGCGC
CGGTACCGA
CGCTAGGCA
20. The following is a sequence of mRNA bases:
G CU U C U C CU
What sequence of amino acids results after translation occurs?
21.
Consider the following portion of an mRNA strand:
UAC GGG AUA
What are the anticodons that will be paired to this strand?
a) AT G CCC TAT
b) AT A GGG TAC
c) AUG CCC UAU
d) UAC GGG AUA
22.
Complete the following chart comparing DNA replication and protein synthesis:
DNA replication
Location where it occurs
Product
Types of nucleic acids used
during this process
Protein synthesis
C. Mutation
23. The DNA strand C GA T G C G A C A T T undergoes a mutation in which the section coding for the
amino acid threonine is lost. Which of the following would be the correct codons after this mutation?
a) A C G C U G U AA
b) G C U A C G C UG
c) G C U C U G U AA
d) G C U A C G U AA
24. Give an explanation for how the following occurs:
a) Sometimes a change of one nucleotide in a gene can result in a different polypeptide.
b) Sometimes a change of one nucleotide in gene will not result in a different polypeptide.
c)
Use the genetic code to give a specific example.
25. An investigation was carried out to examine the probable effects of addition and substitution mutations.
A diagram of a section of DNA is shown:
CATGGTTAC
GTACCAATG
The bold strand reading from left to right is the one used to produce a polypeptide. Use the table of mRNA
codons to determine your answers.
a)
Give the sequence of bases on the mRNA and the resulting sequence of amino acids produced.
b) If a third cytosine (C) is added between the two already found in the bold strand of the original
DNA, give the sequences on the mRNA and the resulting sequence of amino acids produced.
c)
If the guanine (G) at the start of the original DNA strand is deleted, give the sequences on the
mRNA and the resulting sequence of amino acids produced.
d) Explain which of the mutations described in parts b and c would result in the greatest change in
the structure of the original polypeptide.
e)
List 2 environmental mutagens which could cause the changes described in parts b & c.