Biology 314 Final ACTUAL EXAM REVIEW 150
QUESTIONS AND CORRECT ANWERS COVERING THE
MOST RECENT TESTED QUESTIONS GUARANTEE OVER
80% PASSMARK
Which of the following descriptions is consistent with the behavior of a cell that lacks a protein required
for a checkpoint mechanism that operates in G2?
* The cell would pass through M phase more slowly than normal cells
* The cell would enter M phase under conditions when normal cells would not.
* The cell would be unable to enter G2.
* The cell would be unable to enter M phase. - correct answer -The cell would enter M phase under
conditions when normal cells would not.
Which of the following statements about cell growth regulation is FALSE?
*The normal function of the myostatin gene is to inhibit excessive muscle growth.
*A naturally occurring mutation in the myostatin gene has been used to produce certain breeds of
livestock.
* The myostatin gene encodes a secreted signaling protein.
*Mutations in the myostatin gene have opposite effects in cattle and mice. - correct answer -
Mutations in the myostatin gene have opposite effects in cattle and mice.
Which of the following statements about the anaphase promoting complex (APC) is FALSE?
*The APC is a ubiquitin ligase complex that marks specific proteins by polyubiquitination.
*The APC is required for chromosome separation because it promotes activity of a protease that
degrades the cohesin proteins that join the sister chromatids together.
*The APC promotes cell cycle progression by targeting cyclin proteins for degradation at the end of
different phases of the cell cycle.
* The APC is a 26s proteasome that degrades specific protein targets. - correct answer -The APC is a
26s proteasome that degrades specific protein targets.
Which of the following statements about cell death is FALSE?
,*Apoptosis is critical for the morphogenetic movements of epithelia during the early development of
many embryos.
*Apoptosis is the default program in many neurons and must be overcome by specific signals for the
cells to survive.
*Every nucleated animal cell contains procaspases that can be activated to trigger apoptosis.
*Necrosis tends to promote a tissue inflammation response while apoptosis mostly avoids causing
inflammation. - correct answer -Apoptosis is critical for the morphogenetic movements of epithelia
during the early development of many embryos.
Which of the following statements about cellulose is FALSE?
*Glucose monomers are transported across the plasma membrane during the synthesis of a cellulose
polymer.
*Integrin connects microtubules inside the cell to cellulose fibers outside the cell.
*Cellulose synthase enzyme is an integral membrane protein complex.
*Microtubules guide the direction that cellulose synthases move as they produce cellulose fibers. -
correct answer -Integrin connects microtubules inside the cell to cellulose fibers outside the cell.
Which of the following statements about plant cell walls is FALSE?
*Plant cell walls contain proteins with structural functions as well as enzymes that modify cross-linking
of cellulose fibers.
*Plant cell walls consist of cellulose fibers cross-linked by hydrogen bonds to other carbohydrates.
*Auxin induces plant cell expansion by promoting depolymerization of cellulose fibers.
*Secondary cell walls are thicker and more rigid than primary cell walls and located between the
primary wall and cell membrane. - correct answer -Auxin induces plant cell expansion by promoting
depolymerization of cellulose fibers.
A defining characteristic of connective tissue in animals is
* that it is always associated with the skeleton in some way.
*it does not contain fibronectin.
*it contains extensive extracellular matrix.
*that once it is mature, it can never be remodeled. - correct answer -it contains extensive extracellular
matrix.
,Which of the following statements about extracellular matrices is FALSE?
*The major plant cell wall fiber is a carbohydrate while in the animal ECM the major fiber is a protein.
*Both cellulose and collagen are synthesized by enzymes embedded in the plasma membrane as they
are simultaneously exported to the extracellular matrix.
*Like the extracellular matrix in animals, the cell wall of plants can be thin and flexible in some cells,
thick and rigid in others.
*Both animal and plant cells are capable of modifying their extracellular matrices in certain
circumstances. - correct answer -Both cellulose and collagen are synthesized by enzymes embedded in
the plasma membrane as they are simultaneously exported to the extracellular matrix.
Which of the following statements about cell crawling is FALSE?
*As cells crawl through a tissue, they form focal adhesions which connect their actin cytoskeleton to
proteins of the ECM.
*Directional cues can be provided to cells by proteoglycans which are specifically recognized by integrin
proteins.
*Some cells can crawl through the ECM following directional cues provided by paracrine signals.
*Cells can crawl through a tissue in part because they are able to remodel the ECM by secreting
proteases. - correct answer -Directional cues can be provided to cells by proteoglycans which are
specifically recognized by integrin proteins.
Which of the following statements about collagen is FALSE?
*Collagen in an animal ECM consists of protein monomers, wound into triple stranded helices, that are
then assembled into fibers.
*Procollagen is secreted from the cell, then proteolytically cleaved to allow assembly into fibers.
*Collagen fibers can be realigned by fibroblast cells crawling through them.
*Collagen fibers can be rapidly disassembled and reassembled during cell division by phosphorylating
their protein subunits. - correct answer -Collagen fibers can be rapidly disassembled and reassembled
during cell division by phosphorylating their protein subunits.
Which of the following is NOT a property of proteoglycans?
*They seal the ECM between epithelial cells, preventing diffusion of solutes from one side of the
epithelium to the other.
, *Their negative charges contribute to their ability to filter certain secreted signaling molecules,
inhibiting their diffusion through the ECM.
*They consist of huge aggregates of core proteins with many polysaccharide chains attached.
*They impart a large osmotic effect that draws water into the ECM. - correct answer -They seal the
ECM between epithelial cells, preventing diffusion of solutes from one side of the epithelium to the
other.
Which of the following is NOT a property of the basal lamina of epithelia?
*Interactions between the basal lamina and integrins help impart polarity to epithelial cells.
*It provides mechanical reinforcement.
*Collagen proteins form a major reinforcing fiber of basal laminas.
*Only simple epithelia have basal laminas, stratified epithelia produce layers of keratinocytes. - correct
answer -Only simple epithelia have basal laminas, stratified epithelia produce layers of keratinocytes.
Which of the following is NOT an example of a function performed by epithelia?
*They can have secretory functions such as mucus or hormones.
*They provide cushioning such as in bone joints.
*They provide protection against pathogens or other environmental factors.
*They control the transport of solutes into or out of a lumen or organ. - correct answer -They provide
cushioning such as in bone joints.
Which of the following is NOT true of epithelial polarity?
*In the lining of body cavities, the apical end of epithelial cells always faces the lumen.
*Polar orientation of microtubules contributes to cytoplasmic organization of epithelial cells.
*The apical end of epithelial cells is always devoted to transport of materials into the cells, whereas the
transport of materials out of the cell always occurs at the basal end.
*Hemidesmosomes are located primarily on the basal end of epithelial cells. - correct answer -The
apical end of epithelial cells is always devoted to transport of materials into the cells, whereas the
transport of materials out of the cell always occurs at the basal end.
Which statement about cell junction proteins is FALSE?
QUESTIONS AND CORRECT ANWERS COVERING THE
MOST RECENT TESTED QUESTIONS GUARANTEE OVER
80% PASSMARK
Which of the following descriptions is consistent with the behavior of a cell that lacks a protein required
for a checkpoint mechanism that operates in G2?
* The cell would pass through M phase more slowly than normal cells
* The cell would enter M phase under conditions when normal cells would not.
* The cell would be unable to enter G2.
* The cell would be unable to enter M phase. - correct answer -The cell would enter M phase under
conditions when normal cells would not.
Which of the following statements about cell growth regulation is FALSE?
*The normal function of the myostatin gene is to inhibit excessive muscle growth.
*A naturally occurring mutation in the myostatin gene has been used to produce certain breeds of
livestock.
* The myostatin gene encodes a secreted signaling protein.
*Mutations in the myostatin gene have opposite effects in cattle and mice. - correct answer -
Mutations in the myostatin gene have opposite effects in cattle and mice.
Which of the following statements about the anaphase promoting complex (APC) is FALSE?
*The APC is a ubiquitin ligase complex that marks specific proteins by polyubiquitination.
*The APC is required for chromosome separation because it promotes activity of a protease that
degrades the cohesin proteins that join the sister chromatids together.
*The APC promotes cell cycle progression by targeting cyclin proteins for degradation at the end of
different phases of the cell cycle.
* The APC is a 26s proteasome that degrades specific protein targets. - correct answer -The APC is a
26s proteasome that degrades specific protein targets.
Which of the following statements about cell death is FALSE?
,*Apoptosis is critical for the morphogenetic movements of epithelia during the early development of
many embryos.
*Apoptosis is the default program in many neurons and must be overcome by specific signals for the
cells to survive.
*Every nucleated animal cell contains procaspases that can be activated to trigger apoptosis.
*Necrosis tends to promote a tissue inflammation response while apoptosis mostly avoids causing
inflammation. - correct answer -Apoptosis is critical for the morphogenetic movements of epithelia
during the early development of many embryos.
Which of the following statements about cellulose is FALSE?
*Glucose monomers are transported across the plasma membrane during the synthesis of a cellulose
polymer.
*Integrin connects microtubules inside the cell to cellulose fibers outside the cell.
*Cellulose synthase enzyme is an integral membrane protein complex.
*Microtubules guide the direction that cellulose synthases move as they produce cellulose fibers. -
correct answer -Integrin connects microtubules inside the cell to cellulose fibers outside the cell.
Which of the following statements about plant cell walls is FALSE?
*Plant cell walls contain proteins with structural functions as well as enzymes that modify cross-linking
of cellulose fibers.
*Plant cell walls consist of cellulose fibers cross-linked by hydrogen bonds to other carbohydrates.
*Auxin induces plant cell expansion by promoting depolymerization of cellulose fibers.
*Secondary cell walls are thicker and more rigid than primary cell walls and located between the
primary wall and cell membrane. - correct answer -Auxin induces plant cell expansion by promoting
depolymerization of cellulose fibers.
A defining characteristic of connective tissue in animals is
* that it is always associated with the skeleton in some way.
*it does not contain fibronectin.
*it contains extensive extracellular matrix.
*that once it is mature, it can never be remodeled. - correct answer -it contains extensive extracellular
matrix.
,Which of the following statements about extracellular matrices is FALSE?
*The major plant cell wall fiber is a carbohydrate while in the animal ECM the major fiber is a protein.
*Both cellulose and collagen are synthesized by enzymes embedded in the plasma membrane as they
are simultaneously exported to the extracellular matrix.
*Like the extracellular matrix in animals, the cell wall of plants can be thin and flexible in some cells,
thick and rigid in others.
*Both animal and plant cells are capable of modifying their extracellular matrices in certain
circumstances. - correct answer -Both cellulose and collagen are synthesized by enzymes embedded in
the plasma membrane as they are simultaneously exported to the extracellular matrix.
Which of the following statements about cell crawling is FALSE?
*As cells crawl through a tissue, they form focal adhesions which connect their actin cytoskeleton to
proteins of the ECM.
*Directional cues can be provided to cells by proteoglycans which are specifically recognized by integrin
proteins.
*Some cells can crawl through the ECM following directional cues provided by paracrine signals.
*Cells can crawl through a tissue in part because they are able to remodel the ECM by secreting
proteases. - correct answer -Directional cues can be provided to cells by proteoglycans which are
specifically recognized by integrin proteins.
Which of the following statements about collagen is FALSE?
*Collagen in an animal ECM consists of protein monomers, wound into triple stranded helices, that are
then assembled into fibers.
*Procollagen is secreted from the cell, then proteolytically cleaved to allow assembly into fibers.
*Collagen fibers can be realigned by fibroblast cells crawling through them.
*Collagen fibers can be rapidly disassembled and reassembled during cell division by phosphorylating
their protein subunits. - correct answer -Collagen fibers can be rapidly disassembled and reassembled
during cell division by phosphorylating their protein subunits.
Which of the following is NOT a property of proteoglycans?
*They seal the ECM between epithelial cells, preventing diffusion of solutes from one side of the
epithelium to the other.
, *Their negative charges contribute to their ability to filter certain secreted signaling molecules,
inhibiting their diffusion through the ECM.
*They consist of huge aggregates of core proteins with many polysaccharide chains attached.
*They impart a large osmotic effect that draws water into the ECM. - correct answer -They seal the
ECM between epithelial cells, preventing diffusion of solutes from one side of the epithelium to the
other.
Which of the following is NOT a property of the basal lamina of epithelia?
*Interactions between the basal lamina and integrins help impart polarity to epithelial cells.
*It provides mechanical reinforcement.
*Collagen proteins form a major reinforcing fiber of basal laminas.
*Only simple epithelia have basal laminas, stratified epithelia produce layers of keratinocytes. - correct
answer -Only simple epithelia have basal laminas, stratified epithelia produce layers of keratinocytes.
Which of the following is NOT an example of a function performed by epithelia?
*They can have secretory functions such as mucus or hormones.
*They provide cushioning such as in bone joints.
*They provide protection against pathogens or other environmental factors.
*They control the transport of solutes into or out of a lumen or organ. - correct answer -They provide
cushioning such as in bone joints.
Which of the following is NOT true of epithelial polarity?
*In the lining of body cavities, the apical end of epithelial cells always faces the lumen.
*Polar orientation of microtubules contributes to cytoplasmic organization of epithelial cells.
*The apical end of epithelial cells is always devoted to transport of materials into the cells, whereas the
transport of materials out of the cell always occurs at the basal end.
*Hemidesmosomes are located primarily on the basal end of epithelial cells. - correct answer -The
apical end of epithelial cells is always devoted to transport of materials into the cells, whereas the
transport of materials out of the cell always occurs at the basal end.
Which statement about cell junction proteins is FALSE?
