MCB 3023 FINAL EXAM QUESTIONS WITH VERIFIED
ANSWERS
Which of the following components is characteristic of eukaryote membranes? Select all
that apply.
Cholesterol
Hopanoids
Ergosterol - Answers - Cholesterol
Ergosterol
Which of the following functions is NOT associated to the membranes of the
prokaryotes?
A. Protein secretion
B. Plasmid assembly
C. Transport
D. Osmotic barrier - Answers - B. Plasmid Assembly
Which of the following is true of viruses in the extracellular phase?
A. They can reproduce independently of living cells but only at a slow rate.
B. They behave as a macromolecular complex and are no more alive than are
ribosomes.
C. They possess many different enzymes.
D. They possess many different enzymes and they can reproduce independently of
living cells but only at a slow rate. - Answers - B. They behave as a macromolecular
complex and are no more alive than are ribosomes.
Plasmids are extra-chromosomal DNA molecules that can be found as recombinant
molecules into the chromosome of:
A. Viruses and Bacteria
B. Bacteria
C. Bacteria and Archaea
D. Archaea
E. Viruses - Answers - C. Bacteria and Archaea
,In the Archaea envelopes the presence of a microcrystalline array of proteins
(frequently glycosylated) is the most common structure to be found. This particular
structure is also present in some group of Bacteria and it is called:
A. Inner membrane
B. Outer membrane
C. Lipopolysacharide (LPS)
D. S-Layer - Answers - D. S-Layer
Which of the following molecules is only found in the membrane of Gram negative
Bacteria?
A. None of them.
B. Teichoic acids.
C. Cell wall with glycine inter-bridges.
D. Lipoteichoic acids.
E. All of them. - Answers - A. None of them
Which of the following components of the LPS is a potent endotoxin?
A. Ethanolamine
B. Lipid B
C. O side Chain
D. Lipid A - Answers - D. Lipid A
Carboxysomes are internal prokaryotic cell structures made of proteins. These
polyhedral structures are TRUE cellular micro-compartments inside the prokaryotes
cytoplasms. They contain enzymes (like Rubisco) involved in carbon dioxide fixation.
(T/F) - Answers - True
Identify the list of compounds normally stored in form of inclusion bodies in the
cytoplasm of prokaryotic cells.
A. None of them
B. glycogen - poly-B-hydroxybutyrate - polyphosphate - sulfur globules
C. glycogen - poly-B-hydroxybutyrate - water - sulfur globules
D. glycogen - poly-B-hydroxybutyrate - polyphosphate - water - Answers - B. glycogen -
poly-B-hydroxybutyrate - polyphosphate - sulfur globules
Which of the following functions is NOT associated to the membranes of the
prokaryotes?
A. Osmotic barrier
, B. Protein secretion
C. Transport
D. Plasmid assembly - Answers - D. Plasmid Assembly
Which of the following cell wall characteristics is NOT VITAL for the cell?
A. Helps to determine the shape of the cell
B. Protect the cell from osmotic lysis
C. Protect the cell from toxic substances
D. All of them are vital - Answers - B. Protect the cell from osmotic lysis
Only one amino acid sequence of the following peptides is present in the Gram positive
cell wall. It functions as an interbridge, connecting D-Ala and L-Lys to crosslink the
peptidoglycan (it is called pentaglycine crosslink). Select the correct sequence:
A. Gly-Gly-Gly
B. D-Ala-Gly-Gly-D-Ala-Gly
C. Gly-Gly-Gly-Gly-Gly
D. Gly-Lys-Lys-Gly-Ala - Answers - C. Gly-Gly-Gly-Gly-Gly
A __________ layer consists of diffuse unorganized polysaccharide material that lies
outside the cell wall and is easily removed. - Answers - Slime
The movement of molecules from an area of higher concentration to an area of lower
concentration without the participation of specific carrier molecules is called
A. facilitated diffusion.
B. active transport.
C. passive diffusion.
D. osmosis. - Answers - C. Passive Diffusion
The term used to describe bacteria that have a spherical shape is
A. coccus.
B. vibrio.
C. bacillus.
D. coccobacillus. - Answers - A. Coccus
Which of the following protects bacteria from lysis in dilute solutions and helps to
determine their cellular morphology or shape?
A. capsule
B. plasma membrane
C. gas vacuoles
D. peptidoglycan - Answers - D. Peptidoglycan
ANSWERS
Which of the following components is characteristic of eukaryote membranes? Select all
that apply.
Cholesterol
Hopanoids
Ergosterol - Answers - Cholesterol
Ergosterol
Which of the following functions is NOT associated to the membranes of the
prokaryotes?
A. Protein secretion
B. Plasmid assembly
C. Transport
D. Osmotic barrier - Answers - B. Plasmid Assembly
Which of the following is true of viruses in the extracellular phase?
A. They can reproduce independently of living cells but only at a slow rate.
B. They behave as a macromolecular complex and are no more alive than are
ribosomes.
C. They possess many different enzymes.
D. They possess many different enzymes and they can reproduce independently of
living cells but only at a slow rate. - Answers - B. They behave as a macromolecular
complex and are no more alive than are ribosomes.
Plasmids are extra-chromosomal DNA molecules that can be found as recombinant
molecules into the chromosome of:
A. Viruses and Bacteria
B. Bacteria
C. Bacteria and Archaea
D. Archaea
E. Viruses - Answers - C. Bacteria and Archaea
,In the Archaea envelopes the presence of a microcrystalline array of proteins
(frequently glycosylated) is the most common structure to be found. This particular
structure is also present in some group of Bacteria and it is called:
A. Inner membrane
B. Outer membrane
C. Lipopolysacharide (LPS)
D. S-Layer - Answers - D. S-Layer
Which of the following molecules is only found in the membrane of Gram negative
Bacteria?
A. None of them.
B. Teichoic acids.
C. Cell wall with glycine inter-bridges.
D. Lipoteichoic acids.
E. All of them. - Answers - A. None of them
Which of the following components of the LPS is a potent endotoxin?
A. Ethanolamine
B. Lipid B
C. O side Chain
D. Lipid A - Answers - D. Lipid A
Carboxysomes are internal prokaryotic cell structures made of proteins. These
polyhedral structures are TRUE cellular micro-compartments inside the prokaryotes
cytoplasms. They contain enzymes (like Rubisco) involved in carbon dioxide fixation.
(T/F) - Answers - True
Identify the list of compounds normally stored in form of inclusion bodies in the
cytoplasm of prokaryotic cells.
A. None of them
B. glycogen - poly-B-hydroxybutyrate - polyphosphate - sulfur globules
C. glycogen - poly-B-hydroxybutyrate - water - sulfur globules
D. glycogen - poly-B-hydroxybutyrate - polyphosphate - water - Answers - B. glycogen -
poly-B-hydroxybutyrate - polyphosphate - sulfur globules
Which of the following functions is NOT associated to the membranes of the
prokaryotes?
A. Osmotic barrier
, B. Protein secretion
C. Transport
D. Plasmid assembly - Answers - D. Plasmid Assembly
Which of the following cell wall characteristics is NOT VITAL for the cell?
A. Helps to determine the shape of the cell
B. Protect the cell from osmotic lysis
C. Protect the cell from toxic substances
D. All of them are vital - Answers - B. Protect the cell from osmotic lysis
Only one amino acid sequence of the following peptides is present in the Gram positive
cell wall. It functions as an interbridge, connecting D-Ala and L-Lys to crosslink the
peptidoglycan (it is called pentaglycine crosslink). Select the correct sequence:
A. Gly-Gly-Gly
B. D-Ala-Gly-Gly-D-Ala-Gly
C. Gly-Gly-Gly-Gly-Gly
D. Gly-Lys-Lys-Gly-Ala - Answers - C. Gly-Gly-Gly-Gly-Gly
A __________ layer consists of diffuse unorganized polysaccharide material that lies
outside the cell wall and is easily removed. - Answers - Slime
The movement of molecules from an area of higher concentration to an area of lower
concentration without the participation of specific carrier molecules is called
A. facilitated diffusion.
B. active transport.
C. passive diffusion.
D. osmosis. - Answers - C. Passive Diffusion
The term used to describe bacteria that have a spherical shape is
A. coccus.
B. vibrio.
C. bacillus.
D. coccobacillus. - Answers - A. Coccus
Which of the following protects bacteria from lysis in dilute solutions and helps to
determine their cellular morphology or shape?
A. capsule
B. plasma membrane
C. gas vacuoles
D. peptidoglycan - Answers - D. Peptidoglycan
