ESSENTIAL CELL BIOLOGY TEST BANK
CH #20 EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
A cell can crawl through a tissue because of the transmembrane ____________
proteins that can bind to fibronectin outside of the cell.
(a) integrin
(b) collagen
(c) gap junction
(d) claudin - ANSWER-a
Which of the following statements about integrins is false?
(a) Integrins use adaptor proteins to interact with the microtubule cytoskeleton.
(b) Integrins can switch to an activated state by binding to an extracellular matrix
molecule.
(c) Integrins can switch to an activated state by binding to an intracellular protein.
(d) An activated integrin molecule takes on an extended conformation. - ANSWER-a
Proteoglycans in the extracellular matrix of animal tissues ________________.
(a) chiefly provide tensile strength.
(b) allow cartilage to resist compression.
(c) are linked to microtubules through the plasma membrane.
(d) are polysaccharides composed of glucose subunits. - ANSWER-b
Which of the following statements is false?
(a) Proteoglycans can act as filters to regulate which molecules pass through the
extracellular medium.
(b) The negative charge associated with proteoglycans attracts cations, which cause
water to be sucked into the extracellular matrix.
(c) Proteoglycans are a major component of compact connective tissues but are
relatively unimportant in watery tissues such as the jellylike substance in the interior of
the eye.
(d) Glycosaminoglycans are components of proteoglycan. - ANSWER-c
A basal lamina ______________________.
(a) is a thin layer of connective-tissue cells and matrix underlying an epithelium.
(b) is a thin layer of extracellular matrix underlying an epithelium.
(c) is attached to the apical surface of an epithelium.
(d) separates epithelial cells from each other. - ANSWER-b
Tight junctions ______________________.
(a) allow small, water-soluble molecules to pass from cell to cell.
(b) interact with the intermediate filaments inside the cell.
, (c) are formed from claudins and occludins.
(d) are found in cells in connective tissues. - ANSWER-c
Adherens junctions ______________________.
(a) can be used to bend epithelial sheets into tubes.
(b) are most often found at the basal surface of cells.
(c) are found only in adult tissues.
(d) involve fibronectin and integrin interactions. - ANSWER-a
At desmosomes, cadherin molecules are connected to ________________.
(a) actin filaments.
(b) intermediate filaments.
(c) microtubules.
(d) gap junctions. - ANSWER-b
Hemidesmosomes are important for ______________________.
(a) tubulation of epithelial sheets.
(b) linkages to glycosaminoglycans.
(c) forming the basal lamina.
(d) attaching epithelial cells to the extracellular matrix. - ANSWER-d
A major distinction between the connective tissues in an animal and other main tissue
types such as epithelium, nervous tissue, or muscle is _______________.
(a) the ability of connective-tissue cells such as fibroblasts to change shape.
(b) the amount of extracellular matrix in connective tissues.
(c) the ability of connective tissues to withstand mechanical stresses.
(d) the numerous connections that connective-tissue cells make with each other. -
ANSWER-b
Which of the following statements about gap junctions is false?
(a) Gap junctions are made of connexons.
(b) Molecules up to 1000 daltons in molecular mass can move across gap junctions.
(c) Because gap junctions do not allow ions to pass through, they are not used for
electrically coupling cells.
(d) Gap junctions can close in response to extracellular signals. - ANSWER-c
Which type of junction involves a connection to the actin cytoskeleton?
(a) adherens junctions
(b) desmosomes
(c) tight junctions
(d) gap junctions - ANSWER-a
Which type of junction contributes the most to the polarization of epithelial cells?
(a) adherens junctions
(b) desmosomes
(c) tight junctions
CH #20 EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
A cell can crawl through a tissue because of the transmembrane ____________
proteins that can bind to fibronectin outside of the cell.
(a) integrin
(b) collagen
(c) gap junction
(d) claudin - ANSWER-a
Which of the following statements about integrins is false?
(a) Integrins use adaptor proteins to interact with the microtubule cytoskeleton.
(b) Integrins can switch to an activated state by binding to an extracellular matrix
molecule.
(c) Integrins can switch to an activated state by binding to an intracellular protein.
(d) An activated integrin molecule takes on an extended conformation. - ANSWER-a
Proteoglycans in the extracellular matrix of animal tissues ________________.
(a) chiefly provide tensile strength.
(b) allow cartilage to resist compression.
(c) are linked to microtubules through the plasma membrane.
(d) are polysaccharides composed of glucose subunits. - ANSWER-b
Which of the following statements is false?
(a) Proteoglycans can act as filters to regulate which molecules pass through the
extracellular medium.
(b) The negative charge associated with proteoglycans attracts cations, which cause
water to be sucked into the extracellular matrix.
(c) Proteoglycans are a major component of compact connective tissues but are
relatively unimportant in watery tissues such as the jellylike substance in the interior of
the eye.
(d) Glycosaminoglycans are components of proteoglycan. - ANSWER-c
A basal lamina ______________________.
(a) is a thin layer of connective-tissue cells and matrix underlying an epithelium.
(b) is a thin layer of extracellular matrix underlying an epithelium.
(c) is attached to the apical surface of an epithelium.
(d) separates epithelial cells from each other. - ANSWER-b
Tight junctions ______________________.
(a) allow small, water-soluble molecules to pass from cell to cell.
(b) interact with the intermediate filaments inside the cell.
, (c) are formed from claudins and occludins.
(d) are found in cells in connective tissues. - ANSWER-c
Adherens junctions ______________________.
(a) can be used to bend epithelial sheets into tubes.
(b) are most often found at the basal surface of cells.
(c) are found only in adult tissues.
(d) involve fibronectin and integrin interactions. - ANSWER-a
At desmosomes, cadherin molecules are connected to ________________.
(a) actin filaments.
(b) intermediate filaments.
(c) microtubules.
(d) gap junctions. - ANSWER-b
Hemidesmosomes are important for ______________________.
(a) tubulation of epithelial sheets.
(b) linkages to glycosaminoglycans.
(c) forming the basal lamina.
(d) attaching epithelial cells to the extracellular matrix. - ANSWER-d
A major distinction between the connective tissues in an animal and other main tissue
types such as epithelium, nervous tissue, or muscle is _______________.
(a) the ability of connective-tissue cells such as fibroblasts to change shape.
(b) the amount of extracellular matrix in connective tissues.
(c) the ability of connective tissues to withstand mechanical stresses.
(d) the numerous connections that connective-tissue cells make with each other. -
ANSWER-b
Which of the following statements about gap junctions is false?
(a) Gap junctions are made of connexons.
(b) Molecules up to 1000 daltons in molecular mass can move across gap junctions.
(c) Because gap junctions do not allow ions to pass through, they are not used for
electrically coupling cells.
(d) Gap junctions can close in response to extracellular signals. - ANSWER-c
Which type of junction involves a connection to the actin cytoskeleton?
(a) adherens junctions
(b) desmosomes
(c) tight junctions
(d) gap junctions - ANSWER-a
Which type of junction contributes the most to the polarization of epithelial cells?
(a) adherens junctions
(b) desmosomes
(c) tight junctions
