Biol 309 Question Bank Cell CommunitiesMultiple Choice1. The orientation of cellulose deposition appears to be determined by.A. the alignment of microtubules below the cell membrane.B. the types of phosopholipids in the underlying cell membrane.C. the density of actin filaments in the cell cortex.D. movement of vesicles along microtubules.2. An epithelium consists of:A. alternating layers of collagen and proteoglycans.B. fibroblast cells embedded within a thick extracellular matrix.C. a layer of specialized cells over connective tissue.D. a group of different cell types encapsulated by connective tissue.3. Which of the following statements correctly describes gap junctions and plasmadesmata?A. They both are present in animal cells.B. These linkages connect the cytoskeletons of adjacent cells.C. They facilitate the movement of cells over connective tissue.D. They are large pores linking adjacent cells.4. The structure of a collagen fiber is most similar toA. intermediate filaments C. actin filamentsB. myosin thick filaments D. microtubules5. Which one of the following statements best describes ‘proteoglycans’?A. These are components of the cell cytoskeleton. B. They creating a swelling force to support tissues.C. They provide tensile and structural strength to connective tissue. D. Proteoglycans provide cell-to-cell recognition and binding.6. Epithelia layer has polarity, which means that:A. Cells are added to one side and removed from the other.B. the cells display different properties on either side.C. there is a different membrane potential on either side.D. the basal side is oriented toward the basal lamina.7. Self-renewal of tissues is possible due to the action of:A. replication of fibroblasts. C. creation of new extracellular matrix.B. migration of new cells into the tissue. D. division of stem cells.8. Unlike an embryonic stem cell, a somatic stem cell.A. is incapable of self renewal. B. will not create terminally differentiated cells.C. can only give rise to a limited number of cell types.D. is only present during early stages of development.Biol 309 Question Bank Cell CommunitiesPage 19. In the classic experiments by Townes and Holfreter, embryotic ectoderm, mesoderm and endoderm cells were disassociated and then recombined. The cells subsequently returned to their original locations within the embryo. Which mechanism most likely allowed the cells to establish their original organization?A. As the cells migrated, they bound to other cells with similar cadherin proteins.B. Embryonic stem cells divided and gave rise to new cells in the original locations.C. Formation of new tight junctions created the correct polarity of the embryo.D. The cells moved to their original locations within the embryo extracellular matrix.10. Which of the above might be functions of tumor suppressor genes? (identify all correct answers)A. cell junction component C. cell surface receptor E. gene suppressor proteinB. gene activator protein D. DNA repair enzyme11. Which of the above might be functions of proto-oncogenes? (identify all correct answers)True/False1. Each cellulose fiber consists of many cellulose molecules.2. The orientation of cellulose strand deposition determines the direction in which the cells can expand.3. A 3-amino acid repeating sequence high in glycine is characteristic of proteoglycan core proteins.4. A GAG is a polysaccharide component of proteoglycans.5. The extracellular matrix of connective tissue is produced by the adjoining epithelial cells.6.Tight junctions are very important in maintaining the polarity of epithelial cells.7. When it divides, a stem cell gives rise to another stem cell.8. Mutations to a tumor suppressor gene often lead to accumulation of other mutations.9. Typically it takes mutations that activate both copies of a particular proto-oncogene to trigger cell division.10. Complete regeneration of entire limbs is possible in humans.11. Genetic engineering of human stem cells is possible in humans.12. Typically, a single mutation is all that is required to make a cell cancerous.Biol 309 Question Bank Cell CommunitiesPage 2Matching1. Cell junction type Function___ Gap junction A. site of linkage between the ECM and the cytoskeleton___ Tight junction B. site of linkage between the cytoskeleton of adjacent cells___ Desmosome C. a large aqueous channel between adjacent cells___ Adheren junction D. couple phosophoslipids to proteopglycans of the ECM___ Hemidesmosome E. form a diffusion barrier within a membraneF. link intermediate filaments of adjacent cells2. Molecule Property___ Proteoglycan A. mediate cell-to-cell recognition and binding.___ Cadherin B. transmembrane proteins that link ECM to cytoskeleton___ Collagen C. consists of a GAG linked to a core peptide___ Integrin D. lie inside the cell membrane and bind to tight junctionsE. filamentous protein that is major component of ECMFill in, etc1. As cells migrate, they respond to and modulate connections to the extracellular matrix through the membrane protein called _____________________. This protein links _________________ filaments of the cytoskeleton through ______________ junctions to _________________ fibers of the ECM. 2. Cells that allow renewal of specific tissue types are called ________________________; if they can give rise to a single cell type they called _____________________________, and if they can give rise to several cell types they are called _________________________. In contrast, cells from early developmental stages that can give rise to any cell type are called ________________________________.3. As a cause of cancer, a mutated G-protein might act as an __________________, whereas its unmutated form would be called a ________________________. 4. Identify in this figure the regions that correspond to the plant cell primarycell wall, secondary cell wall, middle lamella, and cell membrane.Biol 309 Question Bank Cell CommunitiesPage 35. In writing about his investigations of plant cell structure in his classic Micrographia (published in 1695) Robert Hooke was perplexed by the mechanism of transport through plant cell walls:“But though I could not with my Microscope, nor with my breath, nor any other way I have yet tried, discover a passage out of one of those cavities into another, yet I cannot thence conclude, that therefore there are none such, by which the Succus nutritius, or appropriate juices of Vegetables, may pass through