AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
NOTES
PROKARYOTIC
AND
PROKARYOTIC GENOME
Sources of Variation and Recombination
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EUKARYOTIC GENOME
AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
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AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
OPERONS –
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TRP
OPERON
AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
OPERONS –
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LAC
OPERON
AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
EUKARYOTIC GENOME
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AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
HOMEWORK
1.
NAME:_____________________
Listed below are descriptions and examples of the different types of
recombination in bacteria. Classify each type as:
A) transformation
B) transduction
C) conjugation
D) transposons
Bacteria assimilate genetic material from surroundings
Bacteria take up DNA from environment
Gene transfer from one bacterium to another via bacteriophage
Direct transfer of genes between two bacterial temporarily joined by
sex pili
Jumping genes first described by Barbara McClintock
Pieces of DNA move from one location to another location in cell’s
genome
A DNA segment is moved from one location to another
DNA is transferred from one bacterium to another by a virus
A plasmid is exchanged between two bacteria through a pilus
Bacterial strains A and B are growing together in a colony that has
been infected with viruses. After a short period of time, a new
strain of bacteria is detected that is very similar to strain A but
has a few characteristics of B.
The conversion of live R strain Streptococcus pneumoniae into S
strain when heat-killed S strain is added to R strain
E. coli bacteria are induced to take up the pBLU plasmid
2.
List and describe the two main strategies used by cells to control
metabolism.
METHOD OF CONTROL
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DESCRIPTION OF METHOD
AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
3.
4.
Match the description/function with the correct term.
Regulated cluster of adjacent structural
genes with related functions
Gene that codes for polypeptide
A. Corepressor
Transcript of several genes; translated
into several polypeptides
RNA segment between promoter &
structural genes; controls access of
RNA polymerase to structural gene
Specific protein that binds to operator
and blocks transcription
Genes that code for repressor or
regulators of other genes
RNA polymerase binding site
C. Operon
Molecule that binds to repressor
protein; complex then binds to operator
H. Structural gene
Explain how the trp operon works:
a.
If tryptophan is absent from the cell.
b.
If tryptophan is present in the cell
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B. Operator
D. Polycistronic
mRNA
E. Promoter
F. Regulatory
gene
G. Repressor
AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
5.
Explain how tryptophan acts as a corepressor.
6.
Match these components of the lac operon with their functions.

7.
-galactosidase
A.
cAMP-CAP complex
B.
lactose
C.
operator
D.
promoter
E.
regulator gene
F.
repressor
G.
structural gene
H.
is inactivated when
attached to lactose
codes for synthesis of
repressor
hydrolyzes lactose
stimulates gene
expression
repressor attaches here
RNA polymerase attaches
here
acts as inducer that
inactivates repressor
codes for an enzyme
Listed below are characteristics of repressible and inducible enzymes.
Identify each of the following as true of repressible or inducible enzymes.
genes are switched off until a specific metabolite inactivates the
repressor
genes are switched on until a specific metabolite activates the
repressor
Generally function in anabolic pathways
Usually function in catabolic pathways
Pathway end product switches off its own production
Enzyme synthesis is switched on by the nutrient in used in the
pathway
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AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
8.
The events listed below describe how the lac operon functions when lactose
is present and glucose is absent. Put the steps in the correct order.
Allolactose binds to repressor
cAMP accumulates
cAMP activates CAP
cAMP binds to CAP
cAMP/CAP complex binds to CAP site in promoter
CAP concentration increases
Genes transcribed
Repressor inactivated
RNA polymerase binds to promoter
9.
Explain how the lac operon functions when both lactose and glucose are
present in the cell.
10.
Match the term with the correct definition or description.
A.
C.
E.
G.
30-nm chromatin fiber
Heterochromatin
Looped domains
Nucleosomes
B. Euchromatin
D. Histone proteins
F. Metaphase chromosome
Small proteins associate with DNA packing
Beads on a string; DNA wound around histone proteins
Tightly would coil with 6 nucleosomes per turn; molecules of one
type of histone protein pull the nucleosomes into a cylinder with
a diameter of 30 nm
Loops of 30-nm chromatin fibers; each loop contains 20,000 to
100,000 base pairs
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AP BIOLOGY CHAPTER 18-REGULATION OF GENE EXPRESSION
NOTES AND HOMEWORK
Folding of the looped domains
Chromatin that remains highly condensed during interphase;
actively transcribed
not
Chromatin that is less condensed during interphase; actively
transcribed
11.
Listed below are the levels of chromatin (DNA) packing in the eukaryotic
genome. Put them in the correct order starting with the least condensed.
Looped domains
Nucleosomes
Metaphase chromosome
30-nm chromatin fiber
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