general-biology-181-quiz-2.pdf

lOMoARcPSD|46828873 general biology 181 quiz 2 General Biology I (Grand Canyon University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Elisa Schiau (elisaschiau2@gmail...

lOMoARcPSD|46828873 general biology 181 quiz 2 General Biology I (Grand Canyon University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 1. Which of the following statements is correct about diffusion? a. It is very rapid over long distances b. It requires an expenditure of energy by the cell c. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration d. It is an active process in which molecules move from a region of lower concentration to one of higher concentration e. It requires integral proteins in the cell membrane 2. According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids a. They can move laterally along the plane of a membrane b. They frequently flip flop from one side of the membrane to the other c. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane d. They are free to depart from the membrane and dissolve in the surrounding solution e. They have hydrophobic tails in the interior of the membrane 3. Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? a. Dehydration reactions assemble polymers, and hydrolysis break down polymers b. Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable c. Dehydration reactions can occur only after hydrolysis d. Hydrolysis creates monomers, and dehydration reactions break down polymers e. Dehydration reacts ionize water molecules and add hydroxyl groups to polymers; hydrolysis reactions release hydroxyl groups from polymers 4. In a plant cell, DNA may be found a. Only in the nucleus b. Only in the nucleus and mitochondria c. Only in the nucleus and chloroplasts d. In the nucleus, mitochondria, and chloroplasts e. In the nucleus, mitochondria, and chloroplasts and peroxisomes 5. A primary objective of cell fractionation is to a. View the structure of cell membranes b. Sort cells based on their size and weight c. Determine the size of various organelles d. Separate the major organelles so that their particular functions can be determined e. Separate lipid soluble from water soluble molecules 6. Which structure is the site of the synthesis of proteins that may be exported from the cell a. Rough ER b. Lysosomes c. Plasmodesmata d. Golgi vesicles e. Free cytoplasmic ribosomes 7. What results from an unequal sharing of electrons between atoms? Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 a. A non-polar covalent bond b. A polar covalent bond c. An ionic bond d. Hydrogen bond e. A hydrophobic interaction 8. Movement of vesicles within the cell depends on what cellular structures? a. Microtubules and motor proteins b. Actin filaments and microtubules c. Actin filaments and ribosomes d. Centrioles and motor proteins e. Actin filaments and motor proteins 9. Ions diffuse across membranes through specific ion channels a. Down their chemical gradients b. Down their concentration gradients c. Down their electrical gradients d. Down their electrochemical gradients e. Down the osmotic potential gradients 10. The difference between pinocytosis and receptor mediated endocytosis is that a. Pinocytosis brings only water molecules into the cell, but receptor mediated endocytosis brings in other molecules as well b. Pinocytosis increases the surface area of the plasma membrane whereas receptor mediated endocytosis decreases the plasma membrane surface area c. Pinocytosis is non-selective in the molecules it brings into the cell, whereas receptor mediated endocytosis offers more selectivity d. Pinocytosis requires cellular energy but receptor mediated endocytosis does not e. Pinocytosis can concentrate substances from the extracellular fluid, but receptor mediated endocytosis cannot 11. Which plant cell organelle contains its own DNA and ribosomes? a. Glyoxysome b. Vacuoles c. Mitochondrion d. Golgi apparatus e. Peroxisome 12. The liver is involved in detoxification of my poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? a. Rough ER b. Smooth ER c. Golgi apparatus d. Nuclear envelope e. Transport vesicles 13. What maintains the secondary structure of a protein? a. Peptide bonds b. Hydrogen bonds between the amino groups of one peptide bond and the carboxyl group of another peptide bond Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 c. Disulfide bonds d. Hydrophobic interactions e. Hydrogen bonds between the R groups 14. Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures a. The double bond forms kinks in the fatty acid tails, preventing adjacent lipids from packing tightly b. Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes c. Unsaturated fatty acids are more polar than saturated fatty acids d. The double bonds block interactions among the hydrophilic head groups of the lipids e. The double bonds result in shorter fatty acid tails and thinner membrane 15. A protein that spans the phospholipid bilayer one or more time is a. A transmembrane protein b. An integral protein c. A peripheral protein d. An integrin e. A glycoprotein 16. Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through a. Plasmodesmata b. Intermediate filaments c. Tight junctions d. Desmosomes e. Gap junctions 17. Proton pumps are used in various ways by members of every domain of organisms: bacteria, archaea and eukarya. According to evolution theory, what does this most probably mean? a. Proton pumps must have evolved before any living organisms were present on earth b. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life c. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism d. Cells of each domain evolved proton pumps independently when oceans became more acidic e. Proton pumps are necessary to all cell membranes 18. What kinds of molecules pass through a cell membrane most easily? a. Large and hydrophobic b. Small and hydrophobic c. Large polar d. Ionic e. Monosaccharides such as glucose 19. In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and: a. Combine the hydrogen with water molecules to generate hydrogen peroxide Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 b. Use the hydrogen to break down hydrogen peroxide c. Transfer the hydrogen to the mitochondria d. Transfer the hydrogen to oxygen molecules to generate hydrogen peroxide 20. The advantage of light microscopy over electron microscopy is that: a. Light microscopy provides for higher magnification than electron microscopy b. Light microscopy provides for higher resolving power than electron microscopy c. Light microscopy allows one to view dynamic processes in living cells d. Light microscopy provides higher contrast than electron microscopy e. Specimen preparation for light microscopy does not produce artifacts 21. Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater? a. Water will leave the cells, causing them to shrivel and collapse b. NaCl will be exported from the red blood cells by facilitated diffusion c. The blood cells will take up water, swell, and eventually burst d. NaCl will passively diffuse into the new red blood cells e. Blood cells will expend ATP for active transport of NaCl into the cytoplasm 22. Which of the following contains hydrolytic enzymes? a. Lysosomes b. Vacuoles c. Mitochondrion d. Golgi apparatus e. Peroxisome 23. Which of the following produced and modifies polysaccharides that will be secrete? a. Lysosome b. Vacuoles c. Mitochondrion d. Golgi apparatus e. Peroxisome 24. The primary function of polysaccharides attached to the glycoproteins and to glycolipids of animal cell membranes is a. To facilitate diffusion of molecules of molecules down their concertation gradients b. To actively transport molecules against their concertation gradients c. To maintain the integrity of a fluid mosaic membrane d. To maintain membrane fluidity at low temperatures e. To mediate cell-to-cell recognition 25. A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in a. Peroxisomes b. Lysosomes c. Golgi vesicles d. Vacuoles e. Secondary vesicles 26. In a paramecium, cell surface integral membrane proteins are synthesized a. In the cytoplasm by free ribosomes Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 b. By ribosomes in the nucleus c. By ribosomes bound in the rough ER d. By ribosomes in the Golgi vesicles e. By ribosomes bound in the inner surface of the plasma membrane 27. Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules a. Lipids b. Glycogen c. Proteins d. Cellulose e. Nucleic acids 28. The presence of cholesterol in the plasma membranes of some animals a. Enables the membrane to stay fluid more easily when cell temperate drops b. Enables the animal to remove hydrogen atoms from saturated phospholipids c. Enables the animal to add hydrogen atoms to unsaturated phospholipids d. Makes the membrane less flexible, allowing it to sustain greater pressure from within the cell e. Makes the animal more susceptible to circulatory disorders 29. Water passes quickly through cell membranes because a. The bilayer is hydrophilic b. It moves through hydrophilic channels c. Water movement is tied to ATP hydrolysis d. It is a small, polar, charged molecule e. It moves through aquaporin’s in the membrane 30. In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do their end up after endocytosis? a. On the outside of the of vesicles b. On the inside surface of the cell membrane c. On the inside surface of the vesicles d. On the outer surface of the nucleus e. On the ER 31. A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from: a. A bacterium b. An animal, but not a plant c. Nearly any eukaryotic organism d. Any multicellular organism, like a plant or animal e. Any kind of organism 32. Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. As a result, these lipid rafts: a. Are more fluid than the surrounding membrane b. Are more rigid than the surrounding membrane c. Are able to flip flop form inside to outside d. Detach from the plasma membrane and clog arteries Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 e. Have higher rates of lateral diffusion of lipids and proteins into and out of the lipid rafts 33. The partial negative charge in a molecule of water occurs because a. The oxygen atom acquires an additional electron b. The electrons shared between the oxygen and hydrogen atoms spend more them around the oxygen atoms nucleus than around the hydrogen atom nucleus c. The oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms d. One of the hydrogen atoms donates an electron to the oxygen atom 34. Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? a. Sites of energy production in cellular respiration b. Membrane proteins c. Ribosomes d. Cytoskeletal structures e. Cellulose fibers in the cell wall 35. Which of the following is a major cause of the size limits for certain types of cells? a. Limitation on the strength and integrity of the plasma membrane as cell size increases b. The difference in plasma membranes between prokaryotes and eukaryotes c. Evolutionary progression in cell size; more primitive cells have smaller sizes d. The need for a surface area of sufficient area to support the cell’s metabolic needs e. Rigid cell walls that limit cell size expansion 36. Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids? a. Ribosome b. Lysosome c. Smooth endoplasmic reticulum d. Mitochondrion e. Contractile vacuole 37. Which of the following statement concerning bacteria and archaea cells is correct? a. Archaea cells contain small membrane-enclosed organelles; bacteria do not b. Archaea cells contain a membrane-bound nucleus; bacteria do not c. DNA is present in both archaea cells and bacteria cells d. DNA is present in the mitochondria of both bacteria and archaea cells 38. Cell membranes are asymmetrical. Which of the following is the most likely explanation? a. The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium b. Cell membranes communicate signals from one organism to another c. The two sides of a cell membrane face different environments and carry our different functions d. The “innerness” and “oterness” of membrane surfaces are predetermined by genes e. Proteins can only be associated with the cell membranes on the cytoplasmic side 39. A cell with a predominance of free ribosomes is most likely: a. Producing primarily proteins for secretion b. Producing primarily cytoplasmic proteins Downloaded by Elisa Schiau ([email protected])  lOMoARcPSD|46828873 c. Constructing an extensive cell wall or extracellular matrix d. Digesting large food particles e. Enlarging its vacuole Downloaded by Elisa Schiau ([email protected])