BIO101
Practice test Campbell Chapter 7. See end of test for key. Which one of the following cell structures exhibits selective permeability between a cell and its external environment? ( Overview) the plasma membrane mitochondria chloroplasts endoplasmic reticulum lysosomes
Which of the following statements about the role of phospholipids in forming membranes is correct? ( Concept 7.1) Phospholipids are completely insoluble in water. Phospholipids form a single sheet in water. Phospholipids form a structure in which the hydrophobic portion faces outward. Phospholipids form a selectively permeable structure. They are triacylglycerols, which are commonly available in foods.
The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true? ( Concept 7.1) The fluid component of the membrane is composed of phospholipids, and the mosaic part is composed of carbohydrates. The fluid aspect of the membrane describes its structure at normal temperatures, and the mosaic aspect describes the membrane as the temperature is lowered. The mosaic comprises the carbohydrate chains on the inner surface of the membrane. The fluid component of the membrane is phospholipid, and the mosaic is protein. Only phospholipids are capable of moving in the membrane.
BIO101
Which of the following types of information is (are) most likely to be derived from freeze-fracture of biological samples? ( Concept 7.1) the coded information in DNA thin sections (slices) of fixed and embedded cells proteins embedded in membrane bilayers patterns of movement in living cells all of the above
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found? ( Concept 7.1) on the outside (external) surface of the membrane in the interior of the membrane on the inside (cytoplasmic) surface in the interior and on the inside surface, but not on the outside surface on either surface of the membrane, but not in the interior of the membrane Which of the following functional processes result(s) from the presence of proteins in or on the plasma membrane? ( Concept 7.1) enzymatic activity cell-cell recognition intercellular joining cell-cell communication all of the above
Which of the following is/are a function of membrane proteins? (
Concept 7.1)
BIO101
Membrane proteins attach the membrane to the cytoskeleton. Membrane proteins provide receptors for chemical messengers. All of the answers are correct. Membrane proteins with short sugar chains form identification tags that are recognized by other cells.
Which one of the following molecules is most likely to diffuse freely across the lipid bilayer of the plasma membrane without the involvement of a transport protein? ( Concept 7.2) carbon dioxide glucose sodium ion DNA hemoglobin
Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein? ( Concept 7.2) a large polar molecule a large nonpolar molecule dissolved gases such as oxygen or carbon dioxide a small nonpolar molecule Any of the above would easily diffuse through the membrane.
Which of the following structures is most consistent with the selective permeability property of biological membranes? ( Concept 7.2) proteins sandwiched between two layers of phospholipid
BIO101
proteins embedded in two layers of phospholipid a layer of protein coating a layer of phospholipid phospholipids sandwiched between two layers of protein a phospholipid bilayer with proteins scattered on the surfaces of the membranes
Which of the following statements about passive transport is correct? ( 7.3)
Concept
Passive transport operates independently of diffusion. Passive transport operates independently of the concentrations of the substance being transported. In passive transport, all movement of the transported molecule stops when its concentration is the same on both sides of the membrane. Passive transport does not occur in the human body. Passive transport permits the transported molecule to move in either direction, but the majority of transport occurs down the concentration gradient of the molecule.
Cells A and B are the same size, shape, and temperature, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____. ( Concept 7.3) A; the diffusion gradient there is shallower A; its membrane transport proteins will not be saturated B; the diffusion gradient in cell B is steeper B; the oxygen molecules inside cell B have a higher kinetic energy B; the gradient of oxygen is oriented in the opposite direction compared to cell A
Which one of the following statements about diffusion is true? (
Concept 7.3)
BIO101
It is very rapid over long distances. It requires expenditure of energy by the cell. It is a passive process. It occurs when molecules move from a region of lower concentration to a region of higher concentration. It always requires integral proteins of the cell membrane.
The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution? ( Concept 7.3) distilled water 0.4 M 0.8 M 1.0 M none of the above
A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition? ( Concept 7.3) The added salt would enter the cell, causing the cell to take up water and swell. Water would enter the cell by osmosis, and the cell would swell. Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease. There would be no osmotic movement of water in response to the added salt. The added salt makes the solution hypotonic compared to the cell. Water will enter the cell by osmosis.
If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells? ( Concept 7.3)
BIO101
The red blood cell would burst, and the plant cell would shrink. Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall. Seawater is isotonic to both cells. There will be no change in water content of the cells. Both cells would gain water by osmosis; the red blood cell would burst, and the plant cell would increase in turgor pressure. The red blood cell would shrink, and the plant cell would gain water.
Which of these statements describes some aspect of facilitated diffusion? ( Concept 7.3) Facilitated diffusion is another name for osmosis. Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. Facilitated diffusion requires energy to drive a concentration gradient. Facilitated diffusion of solutes may occur through protein pores in the membrane. There is only one kind of protein pore for facilitated diffusion.
Which of the following is (are) true about facilitated diffusion? (
Concept 7.3)
Facilitated diffusion requires a concentration gradient. Facilitated diffusion requires a membrane. Facilitated diffusion involves proteins. Facilitated diffusion does not involve an outside energy source. all of the above
Green olives may be preserved in brine, which is a 30% salt solution. How does
BIO101
this method of preservation prevent contamination by microorganisms? ( Concept 7.3) Bacterial cells shrivel up in high salt solutions, causing the cell to burst. High salt concentration lowers the pH, thus inhibiting bacterial metabolism. High salt concentration raises the pH, thus inhibiting bacterial metabolism. A 30% salt solution is hypotonic to the bacteria, so they gain too much water and burst. A 30% salt solution is hypertonic to the bacteria, so they lose too much water and cannot survive.
Active transport requires a cell to expend energy. Which of the following statements is true? ( Concept 7.4) Active transport often involves an ATP-powered ion pump and a cotransport protein. Active transport usually uses ATP as its energy source. Active transport moves solutes against the concentration gradient. Active transport requires a protein carrier. all of the above
Which of the following is a correct difference between active transport and facilitated diffusion? ( Concept 7.4) Active transport involves transport proteins, and facilitated diffusion does not. Facilitated diffusion can move solutes against a concentration gradient, and active transport cannot. Active transport can move solutes in either direction across a membrane, but facilitated diffusion can only move in one direction. Facilitated diffusion involves transport proteins, and active transport does not.
BIO101
Active transport requires energy from ATP, and facilitated diffusion does not. Which one of the following pairs correctly matches a membrane transport process to its primary function? ( Concept 7.5) phagocytosis; secretion of large particles from the cell by fusion of vesicles with the plasma membrane exocytosis; the movement of water and solutes out of the cell by vesicle fusion with the plasma membrane pinocytosis; the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane. osmosis; passive diffusion of water and small solutes across a membrane none of the above 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
the plasma membrane Phospholipids form a selectively permeable structure The fluid component of the membrane is phospholipid, and the mosaic is protein proteins embedded in membrane bilayers in the interior of the membrane all of the above All of the answers are correct carbon dioxide a large polar molecule proteins embedded in two layers of phospholipid Passive transport permits the transported molecule to move in either direction, but the majority of transport occurs down the concentration gradient of the molecule 12. the diffusion gradient in cell B is steeper 13. It is a passive process 14. 1.0 M 15. Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease 16. Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall 17. Facilitated diffusion of solutes may occur through protein pores in the membrane 18. all of the above 19. A 30% salt solution is hypertonic to the bacteria, so they lose too much water and cannot survive. 20. all of the above 21. Active transport requires energy from ATP, and facilitated diffusion does not 37. pinocytosis; the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane
