Campbell Biology 2nd Canadian Edition Plus Mastering Biology 2nd Ed By Jane B. Reece – Test Bank A+

Description

1) When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using

1. A) a phase-contrast light microscope.
2. B) a scanning electron microscope.
3. C) a transmission electronic microscope.
4. D) a confocal fluorescence microscope.
5. E) a super-resolution fluorescence microscope.

Answer: C

Type: MC

Topic: Concept 6.1

Skill: Knowledge/Comprehension

2) The advantage of light microscopy over electron microscopy is that

1. A) light microscopy provides for higher magnification than electron microscopy.
2. B) light microscopy provides for higher resolving power than electron microscopy.
3. C) light microscopy allows one to view dynamic processes in living cells.
4. D) light microscopy provides higher contrast than electron microscopy.
5. E) specimen preparation for light microcopy does not produce artifacts.

Answer: C

Type: MC

Topic: Concept 6.1

Skill: Knowledge/Comprehension

3) A primary objective of cell fractionation is to

1. A) view the structure of cell membranes.
2. B) sort cells based on their size and weight.
3. C) determine the size of various organelles.
4. D) separate the major organelles so that their particular functions can be determined.
5. E) separate lipid-soluble from water-soluble molecules.

Answer: D

Type: MC

Topic: Concept 6.1

Skill: Knowledge/Comprehension

4) In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is

1. A) the relative solubility of the component.
2. B) the size and weight of the component.
3. C) the percentage of carbohydrates in the component.
4. D) the presence or absence of nucleic acids in the component.
5. E) the presence or absence of lipids in the component.

Answer: B

Type: MC

Topic: Concept 6.1

Skill: Knowledge/Comprehension

5) Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge?

1. A) ribosomes, nucleus, mitochondria
2. B) chloroplasts, ribosomes, vacuoles
3. C) nucleus, ribosomes, chloroplasts
4. D) vacuoles, ribosomes, nucleus
5. E) nucleus, mitochondria, ribosomes

Answer: E

Type: MC

Topic: Concept 6.1

Skill: Application/Analysis

6) Green fluorescent protein (GFP) can be used to fluorescently label a specific protein in cells by genetically engineering cells to synthesize the target protein fused to GFP. What is the advantage of using GFP fusions to visualize specific proteins, instead of staining cells with fluorescently labelled probes that bind to the target protein?

1. A) GFP fusions enable one to track changes in the location of the protein in living cells; staining usually requires preserved cells.
2. B) GFP fusions enable higher resolution than staining with fluorescent probes.
3. C) GFP permits the position of the protein in the cell more precisely than fluorescent probes.
4. D) GFP permits visualization of protein—protein interactions; fluorescent probes do not.
5. E) GFP fusions are not subject to artifacts; fluorescent probes may introduce background artifacts.

Answer: A

Type: MC

Topic: Concept 6.1

Skill: Application/Analysis

7) What is the reason that a modern electron microscope (TEM) can resolve biological images to the subnanometer level, as opposed to tens of nanometers achievable for the best super-resolution light microscope?

1. A) The focal length of the electron microscope is significantly longer.
2. B) Contrast is enhanced by staining with atoms of heavy metal.
3. C) Electron beams have much shorter wavelengths than visible light.
4. D) The electron microscope has a much greater ratio of image size to real size.
5. E) The electron microscope cannot image whole cells at one time.

Answer: C

Type: MC

Topic: Concept 6.1

Skill: Application/Analysis

8) What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?

1. A) light microscopy
2. B) scanning electron microscopy
3. C) transmission electron microscopy
4. D) confocal fluorescence microscopy
5. E) super-resolution fluorescence microscopy

Answer: A

Type: MC

Topic: Concept 6.1

Skill: Synthesis/Evaluation

9) All of the following are part of a prokaryotic cell except

1. A) DNA.
2. B) a cell wall.
3. C) a plasma membrane.
4. D) ribosomes.
5. E) an endoplasmic reticulum.

Answer: E

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

10) The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that

1. A) plant cells are capable of having a much higher surface-to-volume ratio than animal cells.
2. B) plant cells have a much more highly convoluted (folded) plasma membrane than animal cells.
3. C) plant cells contain a large vacuole that reduces the volume of the cytoplasm.
4. D) animal cells are more spherical, whereas plant cells are elongated.
5. E) plant cells can have lower surface-to-volume ratios than animal cells because plant cells synthesize their own nutrients.

Answer: C

Type: MC

Topic: Concept 6.2

Skill: Synthesis/Evaluation

11) A mycoplasma is an organism with a diameter between 0.1 and 1.0 µm. What does the organism’s size tell you about how it might be classified?

1. A) It must be a single-celled protist.
2. B) It must be a single-celled fungus.
3. C) It could be almost any typical bacterium.
4. D) It could be a typical virus.
5. E) It could be a very small bacterium.

Answer: E

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

12) Which of the following is a major cause of the size limits for certain types of cells?

1. A) limitation on the strength and integrity of the plasma membrane as cell size increases
2. B) the difference in plasma membranes between prokaryotes and eukaryotes
3. C) evolutionary progression in cell size; more primitive cells have smaller sizes
4. D) the need for a surface area of sufficient area to support the cell’s metabolic needs
5. E) rigid cell walls that limit cell size expansion

Answer: D

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

13) Which of the following statements concerning bacteria and archaea cells is correct?

1. A) Archaea cells contain small membrane-enclosed organelles; bacteria do not.
2. B) Archaea cells contain a membrane-bound nucleus; bacteria do not.
3. C) DNA is present in both archaea cells and bacteria cells.
4. D) DNA is present in the mitochondria of both bacteria and archaea cells.
5. E) Bacteria contain mitochondria; Archaea do not.

Answer: C

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

14) The evolution of eukaryotic cells most likely involved

1. A) endosymbiosis of an aerobic bacterium in a larger host cell—the endosymbiont evolved into mitochondria.
2. B) anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygen—the anaerobic bacterium evolved into chloroplasts.
3. C) an endosymbiotic fungal cell evolved into the nucleus.
4. D) acquisition of an endomembrane system, and subsequent evolution of mitochondria from a portion of the Golgi.
5. E) fusion of several prokaryotes to form one larger organism.

Answer: A

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

15) Prokaryotes are classified as belonging to two different domains. What are the domains?

1. A) Bacteria and Eukarya
2. B) Bacteria and Archaea
3. C) Archaea and Protista
4. D) Bacteria and Protista
5. E) Bacteria and Fungi

Answer: B

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

16) If radioactive deoxythymidine triphosphate (dTTP) is added to a culture of rapidly growing bacterial cells, where in the cell would you expect to find the greatest concentration of radioactivity?

1. A) nucleus
2. B) cytoplasm
3. C) endoplasmic reticulum
4. D) nucleoid
5. E) ribosomes

Answer: D

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

17) Which organelle or structure is absent in plant cells?

1. A) mitochondria
2. B) Golgi vesicles
3. C) microtubules
4. D) centrosomes
5. E) peroxisomes

Answer: D

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

18) Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

1. A) lipids
2. B) glycogen
3. C) proteins
4. D) cellulose
5. E) nucleic acids

Answer: C

Type: MC

Topic: Concept 6.3

Skill: Knowledge/Comprehension

19) The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence?

1. A) the loss of all nuclear function
2. B) the inability of the nucleus to divide during cell division
3. C) a change in the shape of the nucleus
4. D) failure of chromosomes to carry genetic information
5. E) inability of the nucleus to keep out destructive chemicals

Answer: C

Type: MC

Topic: Concept 6.3

Skill: Synthesis/Evaluation

20) Recent evidence shows that when chromosomes decondense during interphase, their DNA molecules do not intermingle. Instead, they occupy distinct territories within the nucleus. Considering the structure and location of the following structures, which is most likely to be involved in chromosome location?

1. A) nuclear pores
2. B) the nucleolus
3. C) microfilaments
4. D) the nuclear lamina and matrix
5. E) the nuclear envelope

Answer: D

Type: MC

Topic: Concept 6.3

Skill: Synthesis/Evaluation

21) A cell with a predominance of free ribosomes is most likely

1. A) producing primarily proteins for secretion.
2. B) producing primarily cytoplasmic proteins.
3. C) constructing an extensive cell wall or extracellular matrix.
4. D) digesting large food particles.
5. E) enlarging its vacuole.

Answer: B

Type: MC

Topic: Concepts 6.3, 6.4

Skill: Application/Analysis

22) Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?

1. A) ribosome
2. B) lysosome
3. C) smooth endoplasmic reticulum
4. D) mitochondrion
5. E) contractile vacuole

Answer: C

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

23) Which structure is the site of the synthesis of proteins that may be exported from the cell?

1. A) rough ER
2. B) lysosomes
3. C) plasmodesmata
4. D) Golgi vesicles
5. E) free cytoplasmic ribosomes

Answer: A

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

24) The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity?

1. A) Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
2. B) Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
3. C) Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
4. D) Soluble proteins in the cisternae (interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
5. E) All of the above correctly describe polar characteristics of the Golgi function.

Answer: E

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

25) The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that

1. A) at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope.
2. B) the nuclear envelope is not part of the endomembrane system.
3. C) the nuclear envelope is physically separated from the endoplasmic reticulum.
4. D) small vesicles from the Golgi fuse with the nuclear envelope.
5. E) nuclear pore complexes contain proteins.

Answer: A

Type: MC

Topic: Concept 6.4

Skill: Application/Analysis

26) The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by

1. A) the physical separation of most membranes from each other.
2. B) the transportation of membrane lipids among the endomembrane system by small membrane vesicles.
3. C) the function of the Golgi apparatus in sorting and directing membrane components.
4. D) the modification of the membrane components once they reach their final destination.
5. E) the synthesis of different lipids and proteins in each of the organelles of the endomembrane system.

Answer: C

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

27) Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains these hydrolytic enzymes in animal cells?

1. A) chloroplast
2. B) lysosome
3. C) central vacuole
4. D) peroxisome
5. E) glyoxysome

Answer: B

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

28) Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?

1. A) Prokaryotes are unlikely to be able to secrete proteins because they lack an endomembrane system.
2. B) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.
3. C) Proteins that are secreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane.
4. D) In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell.
5. E) Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell.

Answer: C

Type: MC

Topic: Concept 6.4

Skill: Application/Analysis

29) Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition?

1. A) the endoplasmic reticulum
2. B) the Golgi apparatus
3. C) the lysosome
4. D) mitochondria
5. E) membrane-bound ribosomes

Answer: C

Type: MC

Topic: Concept 6.4

Skill: Application/Analysis

30) The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?

1. A) rough ER
2. B) smooth ER
3. C) Golgi apparatus
4. D) nuclear envelope
5. E) transport vesicles

Answer: B

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

31) Which of the following produces and modifies polysaccharides that will be secreted?

1. A) lysosome
2. B) vacuole
3. C) mitochondrion
4. D) Golgi apparatus
5. E) peroxisome

Answer: D

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

32) Which of the following is a major difference between prokaryotic and eukaryotic cells?

1. A) Prokaryotic cells have more intracellular organelles than eukaryotes.
2. B) Eukaryotic cells have more intracellular organelles than prokaryotes.
3. C) Prokaryotes are not able to carry out aerobic respiration, relying instead on anaerobic metabolism.
4. D) Eukaryotes are able not able to carry out aerobic respiration, relying instead on anaerobic metabolism.
5. E) Prokaryotes are generally larger than eukaryotes.

Answer: B

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

33) Which organelle often takes up much of the volume of a plant cell?

1. A) lysosome
2. B) vacuole
3. C) mitochondrion
4. D) Golgi apparatus
5. E) peroxisome

Answer: B

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

34) Which organelle is the primary site of ATP synthesis in eukaryotic cells?

1. A) lysosome
2. B) vacuole
3. C) mitochondrion
4. D) Golgi apparatus
5. E) peroxisome

Answer: C

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

35) Which plant cell organelle contains its own DNA and ribosomes?

1. A) glyoxysome
2. B) vacuole
3. C) mitochondrion
4. D) Golgi apparatus
5. E) peroxisome

Answer: C

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

36) Which animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen?

1. A) lysosome
2. B) vacuole
3. C) mitochondrion
4. D) Golgi apparatus
5. E) peroxisome

Answer: E

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

37) Thylakoids, DNA, and ribosomes are all components found in which organelle?

1. A) vacuoles
2. B) chloroplasts
3. C) mitochondria
4. D) lysosomes
5. E) nuclei

Answer: B

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

38) In a plant cell, DNA may be found

1. A) only in the nucleus.
2. B) only in the nucleus and mitochondria.
3. C) only in the nucleus and chloroplasts.
4. D) in the nucleus, mitochondria, and chloroplasts.
5. E) in the nucleus, mitochondria, chloroplasts, and peroxisomes.

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

39) Where would you expect to find tight junctions?

1. A) in the epithelium of an animal’s stomach
2. B) between the smooth endoplasmic reticulum and the rough endoplasmic reticulum
3. C) between plant cells in a woody plant
4. D) in the plasma membrane of prokaryotes
5. E) on the surface of Archaea that adhere to rocks

Answer: A

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

40) One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. What eukaryotic organelles or features might have evolved as a part of, or as an elaboration of, the endomembrane system?

1. A) plasma membrane
2. B) chloroplasts
3. C) mitochondria
4. D) nuclear envelope
5. E) peroxisome

Answer: D

Type: MC

Topic: Concepts 6.2-6.5

Skill: Synthesis/Evaluation

41) A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from

1. A) a bacterium.
2. B) an animal, but not a plant.
3. C) nearly any eukaryotic organism.
4. D) any multicellular organism, like a plant or an animal.
5. E) any kind of organism.

Answer: C

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

42) Which type of organelle is found in plant cells but not in animal cells?

1. A) ribosomes
2. B) mitochondria
3. C) nuclei
4. D) plastids
5. E) peroxisome

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

43) Why isn’t the mitochondrion classified as part of the endomembrane system?

1. A) It is a static structure.
2. B) Its structure is not derived from the ER or Golgi.
3. C) It has too many vesicles.
4. D) It is not involved in protein synthesis.
5. E) It is not attached to the outer nuclear envelope.

Answer: B

Type: MC

Topic: Concept 6.5

Skill: Synthesis/Evaluation

44) In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and

1. A) combine the hydrogen with water molecules to generate hydrogen peroxide.
2. B) use the hydrogen to break down hydrogen peroxide.
3. C) transfer the hydrogen to the mitochondria.
4. D) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide.
5. E) break down hydrogen peroxide.

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Application/Analysis

45) How does the cell multiply its peroxisomes?

1. A) They bud off from the Golgi.
2. B) They are brought into the cell from the environment.
3. C) They are built de novo from cytosol materials.
4. D) They split in two after they become sufficiently large.
5. E) The cell synthesizes hydrogen peroxide and encloses it in a membrane.

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

46) Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?

1. A) sites of energy production in cellular respiration
2. B) membrane proteins
3. C) ribosomes
4. D) cytoskeletal structures
5. E) cellulose fibres in the cell wall

Answer: D

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

47) Movement of vesicles within the cell depends on what cellular structures?

1. A) microtubules and motor proteins
2. B) actin filaments and microtubules
3. C) actin filaments and ribosomes
4. D) centrioles and motor proteins
5. E) actin filaments and motor proteins

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

48) The smallest cell structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope is

1. A) a mitochondrion.
2. B) a microtubule.
3. C) a ribosome.
4. D) a microfilament.
5. E) a nuclear pore.

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

49) Which of the following contain the 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules?

1. A) both motile cilia and primary (nonmotile) cilia
2. B) centrioles only
3. C) both flagella and motile cilia
4. D) both basal bodies and primary (nonmotile) cilia
5. E) both centrioles and basal bodies

Answer: C

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

50) Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to

1. A) form cleavage furrows during cell division.
2. B) migrate by amoeboid movement.
3. C) separate chromosomes during cell division.
4. D) extend pseudopods.
5. E) maintain the shape of the nucleus.

Answer: C

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

Property	Microtubules (tubulin polymers)	Microfilaments (actin filaments)	Intermediate filaments
Structure	Hollow tubes; wall consists of 13 columns of tubulin molecules	Two intertwined strands of actin, each a polymer of actin subunits	Fibrous proteins supercoiled into thicker cables
Diameter	25 nm with 15-nm lumen	7 nm	8-12 nm
Main functions	Cell motility	Cell motility	Anchorage

51) The differences among the three categories of cytoskeletal elements outlined in the table above would suggest that each of the following has specialized roles. Which of the following is a correct match? (All three elements are involved in the maintenance of cell shape.)

1. A) microfilaments and the nuclear lamina
2. B) microtubules and cleavage furrow formation
3. C) microfilaments and ciliary motion
4. D) intermediate filaments and cytoplasmic streaming
5. E) microtubules and chromosome movement

Answer: E

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

52) Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities?

1. A) Cilia and flagella arise from the centrioles.
2. B) Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.
3. C) Motor proteins such as dynein must have evolved before any of these four kinds of structure.
4. D) Cilia and flagella coevolved in the same ancestral eukaryotic organism.
5. E) Natural selection for cell motility repeatedly selected for microtubular arrays in circular patterns in the evolution of each of these structures.

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Synthesis/Evaluation

53) If an individual has abnormal microtubules due to a hereditary condition, in which organs or tissues would you expect dysfunction?

1. A) limbs, hearts, areas with a good deal of contraction
2. B) microvilli, alveoli, and glomeruli: cellular projections that increase surface area
3. C) all ducts, such as those from salivary or sebaceous glands, that transport fluids
4. D) sperm, larynx, and trachea: cells and tissues that contain flagella or cilia
5. E) phagocytic cells and white blood cells that exhibit amoeboid movement

Answer: D

Type: MC

Topic: Concept 6.6

Skill: Synthesis/Evaluation

54) Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to

1. A) perform amoeboid movement.
2. B) form cleavage furrows.
3. C) contract muscle fibres.
4. D) extend pseudopodia.
5. E) move vesicles around the cell.

Answer: E

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

55) Which of the following statements about the cytoskeleton is true?

1. A) The dynamic aspect of cytoskeletal function is made possible by the assembly and disassembly of a large variety of proteins into complex aggregates.
2. B) Microfilaments are structurally rigid and resist compression, whereas microtubules resist tension (stretching).
3. C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
4. D) Chemicals that block the assembly of the cytoskeleton would cause little effect on the cell’s response to external signals and stimuli.
5. E) Transport vesicles among the membranes of the endomembrane system produce the cytoskeleton.

Answer: C

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

56) Cells require which of the following to form cilia or flagella?

1. A) centrosomes
2. B) laminin
3. C) actin
4. D) intermediate filaments
5. E) secretory vesicles

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

57) All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in their composition?

1. A) microtubules
2. B) microfilaments
3. C) plant cell walls
4. D) intermediate filaments
5. E) nuclear lamina

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

58) What do the cell walls of plants and the extracellular matrix of animal cells have in common?

1. A) They are largely composed of phospholipids and glycoproteins.
2. B) Their proteins are made by free cytoplasmic ribosomes.
3. C) They form rigid structures that provide structural support for cells but limit their expansion.
4. D) They limit the passage of small molecules.
5. E) They have functional connections with the cytoskeleton inside the cell.

Answer: E

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

59) The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic common to all of these extracellular structures?

1. A) They must block water and small molecules in order to regulate the exchange of matter and energy with their environment.
2. B) They must permit information transfer between the cell’s cytoplasm and the nucleus.
3. C) They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume.
4. D) They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell.
5. E) They are composed of a mixture of lipids and carbohydrates.

Answer: D

Type: MC

Topic: Concept 6.7

Skill: Application/Analysis

60) When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion?

1. A) plasma membrane → primary cell wall → cytoplasm → vacuole
2. B) secondary cell wall → plasma membrane → primary cell wall → cytoplasm → vacuole
3. C) primary cell wall → plasma membrane → cytoplasm → vacuole
4. D) primary cell wall → plasma membrane → lysosome → cytoplasm → vacuole
5. E) primary cell wall → plasma membrane → cytoplasm → secondary cell wall → vacuole

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Application/Analysis

61) A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its

1. A) nuclear lamina and nuclear matrix.
2. B) nuclear matrix and extracellular matrix.
3. C) mitochondria and Golgi apparatus.
4. D) Golgi apparatus and extracellular matrix.
5. E) nuclear pores and secretory vesicles.

Answer: D

Type: MC

Topic: Concept 6.7

Skill: Application/Analysis

62) The extracellular matrix is thought to participate in the regulation of animal cell behaviour by communicating information from the outside to the inside of the cell via which of the following?

1. A) gap junctions
2. B) the nucleus
3. C) DNA and RNA
4. D) integrins
5. E) plasmodesmata

Answer: D

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

63) Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

1. A) peroxisomes
2. B) desmosomes
3. C) gap junctions
4. D) extracellular matrix
5. E) tight junctions

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

64) Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through

1. A) plasmodesmata.
2. B) intermediate filaments.
3. C) tight junctions.
4. D) desmosomes.
5. E) gap junctions.

Answer: E

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

65) Which of the following makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions?

1. A) Cell membranes do not distinguish the types of ions and molecules passing through them.
2. B) Large molecules, such as proteins and RNA molecules, do not readily get through one, much less two, adjacent cell membranes.
3. C) Cell-to-cell communication requires physical attachment of one cell to another.
4. D) Maintenance of tissue integrity and barriers to fluid leakage requires cells to adhere tightly to one another.
5. E) The relative shapelessness of animal cells requires a mechanism for keeping the cells aligned.

Answer: D

Type: MC

Topic: Concept 6.7

Skill: Synthesis/Evaluation

66) Recent evidence shows that signals from the extracellular matrix (ECM) can regulate the expression of genes in the cell nucleus. A likely mechanism is that

1. A) mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signalling.
2. B) intracellular signals might cause changes in the fibronectin binding to the cell surface.
3. C) orientation of microtubules to the ECM can change gene activity.
4. D) integrins that receive signals from the ECM migrate to the nucleus.
5. E) proteoglycans in the ECM undergo endocytosis and produce intracellular signalling molecules.

Answer: A

Type: MC

Topic: Concept 6.7

Skill: Synthesis/Evaluation

67) Signals between the ECM and the cytoskeleton may be transmitted by

1. A) fibronectin.
2. B) proteoglycans.
3. C) integrins.
4. D) collagen.
5. E) middle lamella.

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

68) ECM proteins are made by ribosomes in which part of a eukaryotic cell?

1. A) mitochondria
2. B) cytoplasm
3. C) nuclear envelope
4. D) Golgi apparatus
5. E) rough ER

Answer: E

Type: MC

Topic: Concepts 6.2, 6.7

Skill: Application/Analysis

69) What types of proteins are not synthesized in the rough ER?

1. A) endoplasmic reticulum proteins
2. B) extracellular matrix proteins
3. C) secreted proteins
4. D) mitochondrial proteins
5. E) plasma membrane proteins

Answer: D

Type: MC

Topic: Concepts 6.2-6.7

Skill: Application/Analysis

70) The smallest unit of matter that can be considered alive is the/a

1. A) nucleic acid.
2. B) mitochondria.
3. C) virus.
4. D) cell.
5. E) organism.

Answer: D

Type: MC

Topic: Introduction to Chapter 6

Skill: Knowledge/Comprehension

71) The minimum distance two points can be separated and still discerned as separate is the

1. A) resolution.
2. B) magnification.
3. C) visibility.
4. D) objective magnification.
5. E) contrast.

Answer: A

Type: MC

Topic: Concept 6.1

Skill: Knowledge/Comprehension

Use the following figure to answer the questions below.

72) What type of cell is pictured above?

1. A) Archaea
2. B) Bacteria
3. C) protist
4. D) plant
5. E) animal

Answer: D

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

73) Which two structures are shared by all eukaryotic cells?

1. A) A and C
2. B) A and D
3. C) B and D
4. D) B and E
5. E) C and E

Answer: B

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

74) What is the function of the structure labelled E?

1. A) respiration
2. B) photosynthesis
3. C) maintain cell pressure
4. D) contain DNA
5. E) synthesize lipids

Answer: B

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

75) What is the function of the structure labelled A?

1. A) respiration
2. B) photosynthesis
3. C) maintain cell pressure
4. D) contain DNA
5. E) synthesize lipids

Answer: D

Type: MC

Topic: Concept 6.3

Skill: Knowledge/Comprehension

76) What is the name of the structure labelled B?

1. A) cell wall
2. B) plasma membrane
3. C) nuclear envelope
4. D) cytosol
5. E) endoplasmic reticulum

Answer: A

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

Use the following figure to answer the questions below.

77) In the figure above, identify the rough endoplasmic reticulum.

1. A) A
2. B) B
3. C) C
4. D) D
5. E) The rough endoplasmic reticulum is not visible on this image.

Answer: B

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

78) What is the function of the structure labelled C?

1. A) synthesize lipids
2. B) make membrane proteins
3. C) make cytosolic proteins
4. D) modify protein for transport
5. E) package proteins for export

Answer: C

Type: MC

Topic: Concept 6.3

Skill: Knowledge/Comprehension

79) The structure labelled D functions in

1. A) lipid synthesis.
2. B) membrane production.
3. C) cytosolic protein production.
4. D) modification of proteins for transport.
5. E) package of proteins.

Answer: A

Type: MC

Topic: Concept 6.4

Skill: Knowledge/Comprehension

80) The image above is a ________ image.

1. A) light microscope
2. B) phase contrast
3. C) scanning electron micrograph
4. D) transmission electron micrograph
5. E) confocal

Answer: D

Type: MC

Topic: Concept 6.1

Skill: Application/Analysis

81) The above image is a cross section of a

1. A) centriole.
2. B) basal body.
3. C) microfilament.
4. D) actin.
5. E) flagella.

Answer: E

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

82) You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume?

1. A) Pinch the edges of the cube into small folds.
2. B) Flatten the cube into a pancake shape.
3. C) Round the clay up into a sphere.
4. D) Stretch the cube into a long, shoebox shape.
5. E) Form the cube into a pyramid.

Answer: C

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

83) A biologist wants specifically to examine the surfaces of different types of cells in kidney tubules of small mammals. The cells in question can be distinguished by external shape, size, and 3-D characteristics. Which of the following would be the optimum method for her study?

1. A) transmission electron microscopy
2. B) cell fractionation
3. C) light microscopy using stains specific to kidney function
4. D) light microscopy of living unstained material
5. E) scanning electron microscopy

Answer: E

Type: MC

Topic: Concept 6.1

Skill: Synthesis/Evaluation

84) A newspaper ad for a local toy store indicates that a very inexpensive microscope available for a small child is able to magnify specimens nearly as much as the much more costly microscope available in your college lab. What is the primary reason for the price difference?

1. A) The ad agency is misrepresenting the ability of the toy microscope to magnify.
2. B) The toy microscope does not have the same fine control for focus of the specimen.
3. C) The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.
4. D) The college microscope produces greater contrast in the specimens.
5. E) The toy microscope usually uses a different wavelength of light source.

Answer: C

Type: MC

Topic: Concept 6.1

Skill: Application/Analysis

85) A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively,

1. A) mitochondria and chloroplasts.
2. B) chloroplasts and peroxisomes.
3. C) peroxisomes and chloroplasts.
4. D) chloroplasts and mitochondria.
5. E) mitochondria and peroxisomes.

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Application/Analysis

Use the following information to answer the questions below.

You are investigating different live cells using a light microscope. The first cells you observe are part of a larger organism. They have a clear area in the middle, a defined shape, and you can see many greenish ovals pressed up along the outer edges.

86) You immediately identify this as a(n) ________ cell.

1. A) plant
2. B) animal
3. C) archaea
4. D) bacteria
5. E) protist

Answer: A

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

87) The clear area in the middle is most likely the

1. A) result of poor use of the microscope.
2. B) result of incomplete staining.
3. C) central vacuole.
4. D) nucleus.
5. E) plastid.

Answer: C

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

88) You look at another group of cells; it looks entirely different. They appear independent of each other and are constantly changing shape and “crawling” across the slide. There are large and small structures moving around inside the cells. You identify these cells as

1. A) plant.
2. B) animal.
3. C) archaea.
4. D) bacteria.
5. E) protist.

Answer: E

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

89) The movement inside the cells that you observed are a result of

1. A) cilia movement.
2. B) the interaction of actin and myosin filaments.
3. C) the extracellular matrix.
4. D) cell division.
5. E) intermediate filaments.

Answer: B

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

90) Which structure is not part of the endomembrane system?

1. A) nuclear envelope
2. B) chloroplast
3. C) Golgi apparatus
4. D) plasma membrane
5. E) ER

Answer: B

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

91) Which structure is common to plant and animal cells?

1. A) chloroplast
2. B) wall made of cellulose
3. C) central vacuole
4. D) mitochondrion
5. E) centriole

Answer: D

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

92) Which of the following is present in a prokaryotic cell?

1. A) mitochondrion
2. B) ribosome
3. C) nuclear envelope
4. D) chloroplast
5. E) ER

Answer: B

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

93) Which structure-function pair is mismatched?

1. A) nucleolus; production of ribosomal subunits
2. B) lysosome; intracellular digestion
3. C) ribosome; protein synthesis
4. D) Golgi; protein trafficking
5. E) microtubule; muscle contraction

Answer: E

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

94) Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the

1. A) mitochondria.
2. B) ribosomes.
3. C) peroxisomes.
4. D) lysosomes.
5. E) endoplasmic reticulum.

Answer: A

Type: MC

Topic: End-of-Chapter Questions

Skill: Application/Analysis

95) What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?

1. A) ER → Golgi → nucleus
2. B) Golgi →ER →lysosome
3. C) nucleus →ER →Golgi
4. D) ER →Golgi →vesicles that fuse with plasma membrane
5. E) ER →lysosomes →vesicles that fuse with plasma membrane

Answer: D

Type: MC

Topic: End-of-Chapter Questions

Skill: Application/Analysis

96) Which cell would be best for studying lyosomes?

1. A) muscle cell
2. B) nerve cell
3. C) phagocytic white blood cell
4. D) leaf cell of a plant
5. E) bacterial cell

Answer: C

Type: MC

Topic: End-of-Chapter Questions

Skill: Application/Analysis

97) What are the two domains prokaryotes belong to?

1. A) Bacteria and Eukarya
2. B) Bacteria and Archaea
3. C) Archaea and Protista
4. D) Bacteria and Protista
5. E) Eukarya and Protista

Answer: B

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

98) What is the function of the nuclear pore complex?

1. A) It regulates the movement of proteins and RNAs into and out of the nucleus.
2. B) It synthesizes the proteins required to copy DNA and make mRNA.
3. C) It selectively transports molecules out of the nucleus, but prevents all inbound molecules from entering the nucleus.
4. D) It assembles ribosomes from raw materials that are synthesized in the nucleus.
5. E) It allows nucleoli to pass.

Answer: A

Type: MC

Topic: Concept 6.2

Skill: Knowledge/Comprehension

99) What is a cell with an extensive smooth endoplasmic reticulum likely to be is specialized in?

1. A) protein storage
2. B) synthesis of large quantities of lipids
3. C) export protein molecules
4. D) import and export protein molecules
5. E) communication with other cells

Answer: B

Type: MC

Topic: Concept 6.3

Skill: Knowledge/Comprehension

100) Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis, a disease caused by the inhalation of asbestos fibers. Cells will phagocytize asbestos, but are not able to degrade it. As a result, where are asbestos fibers likely to accumulate?

1. A) mitochondria
2. B) ribosomes
3. C) peroxisomes
4. D) lysosomes
5. E) Golgi

Answer: D

Type: MC

Topic: Concept 6.4

Skill: Application/Analysis

101) Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum?

1. A) extracellular matrix
2. B) Golgi apparatus
3. C) mitochondria
4. D) nucleolus
5. E) peroxisomes

Answer: C

Type: MC

Topic: Concept 6.5

Skill: Knowledge/Comprehension

102) Suppose a young boy is always tired and fatigued. It is suspected that he suffering from a metabolic disease. Which of the following organelles is most likely involved in this disease?

1. A) lysosomes
2. B) Golgi apparatus
3. C) ribosomes
4. D) mitochondria
5. E) peroxisomes

Answer: D

Type: MC

Topic: Concept 6.5

Skill: Application/Analysis

103) How do Amoebae move by crawling over a surface?

1. A) Growth of actin filaments form bulges in the plasma membrane.
2. B) Microtubule extensions are set up that vesicles can follow.
3. C) Pseudopods are reinforced with intermediate filaments.
4. D) use of cytoplasmic streaming
5. E) Intermediate filaments condense and decondense in the direction of travel.

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

104) Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the transport process requires energy). Yet, when they put everything together, there was no movement or transport of vesicles. What were they missing?

1. A) an axon
2. B) contractile microfilaments
3. C) endoplasmic reticulum
4. D) motor proteins
5. E) intermediate filaments

Answer: D

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

105) Why do cilia and flagella bend?

1. A) conformational changes in ATP thrust microtubules laterally
2. B) due to a motor protein called radial spokes
3. C) because of the quick inward movements of water by osmosis
4. D) as a result of a motor protein called dynein
5. E) because of assembly and disassembly of actin monomers

Answer: D

Type: MC

Topic: Concept 6.6

Skill: Knowledge/Comprehension

106) Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs). What do you suspect is the consequence of such a defect?

1. A) abnormally shaped RBCs
2. B) an insufficient supply of ATP in the RBCs
3. C) an insufficient supply of oxygen-transporting proteins in the RBCs
4. D) adherence of RBCs to blood vessel walls, causing plaque formation
5. E) inability of RBCs to communicate with other cells

Answer: A

Type: MC

Topic: Concept 6.6

Skill: Application/Analysis

107) What two structural/organellar defects would a mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins most likely cause?

1. A) nuclear matrix and extracellular matrix
2. B) mitochondria and Golgi apparatus
3. C) Golgi apparatus and extracellular matrix
4. D) nuclear pores and secretory vesicles
5. E) cytoskeleton and vesicular traffic

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Application/Analysis

108) In plant cells, how does the middle lamella function?

1. A) allows adjacent cells to adhere to one another
2. B) prevents dehydration of adjacent cells
3. C) maintains the plant’s circulatory system
4. D) allows for gas and nutrient exchange among adjacent cells
5. E) cell structure and support

Answer: A

Type: MC

Topic: Concept 6.7

Skill: Knowledge/Comprehension

109) H. V. Wilson worked with sponges to gain some insight into what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted the cell-cell interaction (cell junctions), and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson’s experiments?

1. A) The two species of sponge had different enzymes that functioned in the reassembly process.
2. B) The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment.
3. C) The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.
4. D) One cell functioned as the nucleus for each organism, thereby attracting only cells with the same pigment.
5. E) Tight junctions were able to reform but gap junctions were not.

Answer: C

Type: MC

Topic: Concept 6.7

Skill: Application/Analysis

110) Gaucher disease is the most common of lipid storage diseases in humans. It is caused

by a deficiency of an enzyme necessary for lipid metabolism. This leads to a collection of

fatty material in organs of the body including the spleen, liver, kidneys, lungs, brain, and

bone marrow. Using your knowledge of the structure of eukaryotic cells, identify the statement below that best explains how internal membranes and the organelles of cells would be involved

in Gaucher disease.

1. A) The mitochondria are most likely defective and do not produce adequate amounts of

ATP needed for cellular respiration.

1. B) The rough endoplasmic reticulum contains too many ribosomes which results in an

overproduction of the enzyme involved in carbohydrate catalysis.

1. C) The lysosomes lack sufficient amounts of enzymes necessary for the metabolism of

lipids.

1. D) The Golgi apparatus produces vesicles with faulty membranes that leak their contents

into the cytoplasm of the cell.

1. E) The gap junctions are not functioning, and cells are not conveying to other cells that they have enough lipids.

Answer: C

Type: MC

Topic: Concept 6.4

Skill: Application/Analysis

111) Both the volume and the surface area for three different cells were measured. These values are listed in the following table:

	Volume	Surface Area
Cell 1	9.3 μm3	22.5 μm2
Cell 2	12.2 μm3	37.1 μm2
Cell 2	12.2 μm3	37.1 μm2

Using data from the table above, select the cell and best explanation for why that cell will be able to eliminate waste most efficiently?

1. A) Cell 1, since it has the smallest volume, and it will not produce as much waste as the other cells.
2. B) Cell 2, since it has the highest surface area-to-volume ratio, which facilitates the exchange of materials between a cell and its environment.
3. C) Cell 3, since it has the largest surface area, which will enable it to eliminate all of its wastes quickly.
4. D) Cell 3 because it is big enough to allow wastes to easily diffuse through the plasma membrane.
5. E) Presuming all cells have the same organelles; thus, they will eliminate waste with the same efficiency.

Answer: B

Type: MC

Topic: Concept 6.2

Skill: Application/Analysis

Campbell Biology, Cdn. Ed., 2e (Reece et al.)

Chapter 7 Membrane Structure and Function

1) The fluid mosaic model of the membrane proposes that membranes

1. A) are a phospholipid bilayer.
2. B) are a phospholipid bilayer between two layers of hydrophilic proteins.
3. C) are a single layer of phospholipids and proteins.
4. D) consist of protein molecules embedded in a fluid bilayer of phospholipids.
5. E) consist of a mosaic of polysaccharides and proteins.

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

2) Which of the following types of molecules are the major structural components of the cell membrane?

1. A) phospholipids and cellulose
2. B) nucleic acids and proteins
3. C) phospholipids and proteins
4. D) proteins and cellulose
5. E) glycoproteins and cholesterol

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

3) When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that

1. A) the integral membrane proteins are not strong enough to hold the bilayer together.
2. B) water that is present in the middle of the bilayer freezes and is easily fractured.
3. C) hydrophilic interactions between the opposite membrane surfaces are destroyed on freezing.
4. D) the carbon—carbon bonds of the phospholipid tails are easily broken.
5. E) the hydrophobic interactions that hold the membrane together are weakest at this point.

Answer: E

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

4) The presence of cholesterol in the plasma membranes of some animals

1. A) enables the membrane to stay fluid more easily when cell temperature drops.
2. B) enables the animal to remove hydrogen atoms from saturated phospholipids.
3. C) enables the animal to add hydrogen atoms to unsaturated phospholipids.
4. D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
5. E) makes the animal more susceptible to circulatory disorders.

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

5) According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

1. A) They can move laterally along the plane of the membrane.
2. B) They frequently flip-flop from one side of the membrane to the other.
3. C) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.
4. D) They are free to depart from the membrane and dissolve in the surrounding solution.
5. E) They have hydrophilic tails in the interior of the membrane.

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

6) Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold?

1. A) by increasing the percentage of unsaturated phospholipids in the membrane
2. B) by increasing the percentage of cholesterol molecules in the membrane
3. C) by decreasing the number of hydrophobic proteins in the membrane
4. D) by cotransport of glucose and hydrogen
5. E) by using active transport

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

7) In order for a protein to be an integral membrane protein, it would have to be

1. A) hydrophilic.
2. B) hydrophobic.
3. C) amphipathic, with at least one hydrophobic region.
4. D) completely covered with phospholipids.
5. E) exposed on only one surface of the membrane.

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Synthesis/Evaluation

8) When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are

1. A) peripheral proteins.
2. B) phospholipids.
3. C) carbohydrates.
4. D) integral proteins.
5. E) cholesterol molecules.

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

9) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?

1. A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.
2. B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes.
3. C) Unsaturated fatty acids are more polar than saturated fatty acids.
4. D) The double bonds block interaction among the hydrophilic head groups of the lipids.
5. E) The double bonds result in shorter fatty acid tails and thinner membranes.

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

10) Which of the following is true of integral membrane proteins?

1. A) They lack tertiary structure.
2. B) They are loosely bound to the surface of the bilayer.
3. C) They are usually transmembrane proteins.
4. D) They are not mobile within the bilayer.
5. E) They serve only a structural role in membranes.

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

11) Which of the following most accurately describes selective permeability?

1. A) An input of energy is required for transport across the membrane.
2. B) Charged molecules pass through a membrane.
3. C) There must be a concentration gradient for molecules to pass through a membrane.
4. D) Only certain molecules are able to cross a cell membrane.
5. E) Amphipathic molecules pass through a membrane.

Answer: D

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

12) An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function?

1. A) transporting ions against an electrochemical gradient
2. B) cell-cell recognition
3. C) maintaining fluidity of the phospholipid bilayer
4. D) attaching to the cytoskeleton
5. E) establishing the diffusion barrier to charged molecules

Answer: B

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

13) In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model?

1. A) The membrane is only fluid across a very narrow temperature range.
2. B) Proteins rarely move, even though they possibly can do so.
3. C) Unsaturated lipids are excluded from the membranes.
4. D) The concentration of protein molecules is now known to be much higher.
5. E) The proteins are known to be made of only acidic amino acids.

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

14) A protein that spans the phospholipid bilayer one or more times is

1. A) a transmembrane protein.
2. B) an integral protein.
3. C) a peripheral protein.
4. D) an integrin.
5. E) a glycoprotein.

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

15) Which of these are not embedded in the hydrophobic portion of the lipid bilayer at all?

1. A) transmembrane proteins
2. B) integral proteins
3. C) peripheral proteins
4. D) integrins
5. E) glycoproteins

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

16) The cell membranes of Arctic ice fish might have which of the following adaptations?

1. A) very long chain fatty acids
2. B) branched isoprenoid lipids
3. C) a high percentage of polyunsaturated fatty acids
4. D) a higher percentage of trans-fatty acids
5. E) no cholesterol

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

17) In a Paramecium, cell surface integral membrane proteins are synthesized

1. A) in the cytoplasm by free ribosomes.
2. B) by ribosomes in the nucleus.
3. C) by ribosomes bound to the rough endoplasmic reticulum.
4. D) by ribosomes in the Golgi vesicles.
5. E) by ribosomes bound to the inner surface of the plasma membrane.

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

18) When a cell is in equilibrium with its environment, which of the following occurs for substances that can diffuse through the cell?

1. A) There is random movement of substances into and out of the cell.
2. B) There is directed movement of substances into and out of the cell.
3. C) There is no movement of substances into and out of the cell.
4. D) All movement of molecules is directed by active transport.
5. E) Molecules move up their concentration gradient.

Answer: A

Type: MC

Topic: Concept 7.3

Skill: Knowledge/Comprehension

19) Cell membranes are asymmetrical. Which of the following is the most likely explanation?

1. A) The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium.
2. B) Cell membranes communicate signals from one organism to another.
3. C) The two sides of a cell membrane face different environments and carry out different functions.
4. D) The “innerness” and “outerness” of membrane surfaces are predetermined by genes.
5. E) Proteins can only be associated with the cell membranes on the cytoplasmic side.

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Synthesis/Evaluation

20) Which of the following is true of the evolution of cell membranes?

1. A) Cell membranes have stopped evolving now that they are fluid mosaics.
2. B) Cell membranes cannot evolve if the membrane proteins do not.
3. C) The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids.
4. D) All components of membranes evolve in response to natural selection.
5. E) An individual organism selects its preferred type of cell membrane for particular functions.

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Synthesis/Evaluation

21) Why are lipids and proteins free to move laterally in membranes?

1. A) The interior of the membrane is filled with liquid water.
2. B) Lipids and proteins repulse each other in the membrane.
3. C) Hydrophilic portions of the lipids are in the interior of the membrane.
4. D) There are only weak hydrophobic interactions in the interior of the membrane.
5. E) Molecules such as cellulose can pull them in various directions.

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

22) What kinds of molecules pass through a cell membrane most easily?

1. A) large and hydrophobic
2. B) small and hydrophobic
3. C) large polar
4. D) ionic
5. E) monosaccharides such as glucose

Answer: B

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

23) Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

1. A) It is a peripheral membrane protein.
2. B) It exhibits a specificity for a particular type of molecule.
3. C) It requires the expenditure of cellular energy to function.
4. D) It works against diffusion.
5. E) It has few, if any, hydrophobic amino acids.

Answer: B

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

24) Nitrous oxide gas molecules diffusing across a cell’s plasma membrane is an example of

1. A) diffusion across the lipid bilayer.
2. B) facilitated diffusion.
3. C) active transport.
4. D) osmosis.
5. E) cotransport.

Answer: A

Type: MC

Topic: Concept 7.2

Skill: Application/Analysis

25) Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?

1. A) CO2
2. B) an amino acid
3. C) glucose
4. D) K+
5. E) starch

Answer: A

Type: MC

Topic: Concept 7.2

Skill: Application/Analysis

26) Which of the following statements is correct about diffusion?

1. A) It is very rapid over long distances.
2. B) It requires an expenditure of energy by the cell.
3. C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
4. D) It is an active process in which molecules move from a region of lower concentration to one of higher concentration.
5. E) It requires integral proteins in the cell membrane.

Answer: C

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

27) Water passes quickly through cell membranes because

1. A) the bilayer is hydrophilic.
2. B) it moves through hydrophobic channels.
3. C) water movement is tied to ATP hydrolysis.
4. D) it is a small, polar, charged molecule.
5. E) it moves through aquaporins in the membrane.

Answer: E

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

28) Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are

1. A) hypotonic to both fresh water and the salt solution.
2. B) hypertonic to both fresh water and the salt solution.
3. C) hypertonic to fresh water but hypotonic to the salt solution.
4. D) hypotonic to fresh water but hypertonic to the salt solution.
5. E) isotonic with fresh water but hypotonic to the salt solution.

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

29) 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?

1. A) Water will leave the cells, causing them to shrivel and collapse.
2. B) NaCl will be exported from the red blood cells by facilitated diffusion.
3. C) The blood cells will take up water, swell, and eventually burst.
4. D) NaCl will passively diffuse into the red blood cells.
5. E) The blood cells will expend ATP for active transport of NaCl into the cytoplasm.

Answer: A

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

30) Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells?

1. A) The animal cell is in a hypotonic solution, and the plant cell is in an isotonic solution.
2. B) The animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution.
3. C) The animal cell is in a hypertonic solution, and the plant cell is in an isotonic solution.
4. D) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution.
5. E) The animal cell is in a hypertonic solution, and the plant cell is in a hypotonic solution.

Answer: D

Type: MC

Topic: Concept 7.3

Skill: Knowledge/Comprehension

31) In which of the following would there be the greatest need for osmoregulation?

1. A) an animal connective tissue cell bathed in isotonic body fluid
2. B) cells of a tidepool animal such as an anemone
3. C) a red blood cell surrounded by plasma
4. D) a lymphocyte before it has been taken back into lymph fluid
5. E) a plant being grown hydroponically (in a watery mixture of designated nutrients)

Answer: B

Type: MC

Topic: Concept 7.3

Skill: Synthesis/Evaluation

32) When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur?

1. A) The cell will burst.
2. B) The cell membrane will lyse.
3. C) Plasmolysis will shrink the interior.
4. D) The cell will become flaccid.
5. E) The cell will become turgid.

Answer: E

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

33) Which of the following membrane activities require energy from ATP hydrolysis?

1. A) facilitated diffusion of chloride ions across the membrane through a chloride channel
2. B) movement of water into a cell
3. C) Na+ions moving out of a mammalian cell bathed in physiological saline
4. D) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell
5. E) movement of carbon dioxide out of a paramecium

Answer: C

Type: MC

Topic: Concept 7.4

Skill: Application/Analysis

34) The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane—more acidic outside the cell than inside the cell. Phosphate transport is an example of

1. A) passive diffusion.
2. B) facilitated diffusion.
3. C) active transport.
4. D) osmosis.
5. E) cotransport.

Answer: E

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

35) Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells?

1. A) simple diffusion
2. B) phagocytosis
3. C) active transport pumps
4. D) exocytosis
5. E) facilitated diffusion

Answer: E

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

36) What is the voltage across a membrane called?

1. A) water potential
2. B) chemical gradient
3. C) membrane potential
4. D) osmotic potential
5. E) electrochemical gradient

Answer: C

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

37) In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by

1. A) cotransport proteins.
2. B) ion channels.
3. C) carrier proteins.
4. D) passive diffusion across the plasma membrane.
5. E) cellular metabolic reactions that create or destroy ions.

Answer: A

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

38) The sodium-potassium pump is called an electrogenic pump because it

1. A) pumps equal quantities of Na+and K+across the membrane.
2. B) pumps hydrogen ions out of the cell.
3. C) contributes to the membrane potential.
4. D) ionizes sodium and potassium atoms.
5. E) is used to drive the transport of other molecules against a concentration gradient.

Answer: C

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

39) Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?

1. A) The sodium ions are moving down their electrochemical gradient while glucose is moving up.
2. B) Glucose entering the cell along its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient.
3. C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell.
4. D) The cotransporter can also transport potassium ions.
5. E) A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.

Answer: E

Type: MC

Topic: Concept 7.4

Skill: Application/Analysis

40) The movement of potassium into an animal cell requires

1. A) low cellular concentrations of sodium.
2. B) high cellular concentrations of potassium.
3. C) an energy source such as ATP.
4. D) a cotransport protein.
5. E) a potassium channel protein.

Answer: C

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

41) Ions diffuse across membranes through specific ion channels

1. A) down their chemical gradients.
2. B) down their concentration gradients.
3. C) down the electrical gradients.
4. D) down their electrochemical gradients.
5. E) down the osmotic potential gradients.

Answer: D

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

42) Which of the following would increase the electrochemical potential across a membrane?

1. A) a chloride channel
2. B) a sucrose-proton cotransporter
3. C) a proton pump
4. D) a potassium channel
5. E) both a proton pump and a potassium channel

Answer: C

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

43) Which of the following is true of osmosis?

1. A) Osmosis only occurs in red blood cells.
2. B) Osmosis is an energy-demanding or “active” process.
3. C) In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.
4. D) In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.
5. E) Osmosis only occurs in eukaryotes

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Knowledge/Comprehension

44) Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

1. A) Proton pumps must have evolved before any living organisms were present on Earth.
2. B) Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
3. C) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.
4. D) Cells of each domain evolved proton pumps independently when oceans became more acidic.
5. E) Proton pumps are necessary to all cell membranes.

Answer: B

Type: MC

Topic: Concept 7.4

Skill: Synthesis/Evaluation

45) Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following?

1. A) antiviral medications that are efficient and work well with all viruses
2. B) antibiotics against the viruses in question
3. C) intravenous feeding techniques
4. D) medication to prevent blood loss
5. E) hydrating drinks that include high concentrations of salts and glucose

Answer: E

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

46) An organism with a cell wall would most likely be unable to take in materials through

1. A) diffusion.
2. B) osmosis.
3. C) active transport.
4. D) phagocytosis.
5. E) facilitated diffusion.

Answer: D

Type: MC

Topic: Concept 7.5

Skill: Application/Analysis

47) White blood cells engulf bacteria through what process?

1. A) exocytosis
2. B) phagocytosis
3. C) pinocytosis
4. D) osmosis
5. E) receptor-mediated exocytosis

Answer: B

Type: MC

Topic: Concept 7.5

Skill: Knowledge/Comprehension

48) Familial hypercholesterolemia is characterized by which of the following?

1. A) defective low-density lipoprotein receptors on the cell membranes
2. B) poor attachment of the cholesterol to the extracellular matrix of cells
3. C) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes
4. D) inhibition of the cholesterol active transport system in red blood cells
5. E) a general lack of glycolipids in the blood cell membranes

Answer: A

Type: MC

Topic: Concept 7.5

Skill: Knowledge/Comprehension

49) The difference between pinocytosis and receptor-mediated endocytosis is that

1. A) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well.
2. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area.
3. C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.
4. D) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not.
5. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.

Answer: C

Type: MC

Topic: Concept 7.5

Skill: Knowledge/Comprehension

50) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?

1. A) on the outside of vesicles
2. B) on the inside surface of the cell membrane
3. C) on the inside surface of the vesicle
4. D) on the outer surface of the nucleus
5. E) on the ER

Answer: C

Type: MC

Topic: Concept 7.5

Skill: Knowledge/Comprehension

51) A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in

1. A) peroxisomes.
2. B) lysosomes.
3. C) Golgi vesicles.
4. D) vacuoles.
5. E) secretory vesicles.

Answer: B

Type: MC

Topic: Concepts 6.4, 7.5

Skill: Knowledge/Comprehension

For the following questions, match the labelled component of the cell membrane in the figure with its description.

52) Which component is the peripheral protein?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: D

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

53) Which component is cholesterol?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: E

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

54) Which component is the fibre of the extracellular matrix?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

55) Which component is a microfilament of the cytoskeleton?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: C

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

56) Which component is a glycolipid?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: B

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

Use the following information to answer the questions below.

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal.

57) Initially, in terms of tonicity, the solution in side A with respect to that in side B is

1. A) hypotonic.
2. B) plasmolyzed.
3. C) isotonic.
4. D) saturated.
5. E) hypertonic.

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

58) After the system reaches equilibrium, what changes are observed?

1. A) The molarity of sucrose and glucose are equal on both sides.
2. B) The molarity of glucose is higher in side A than in side B.
3. C) The water level is higher in side A than in side B.
4. D) The water level is unchanged.
5. E) The water level is higher in side B than in side A.

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. Refer to the figure to answer the following questions.

59) At the beginning of the experiment,

1. A) side A is hypertonic to side B.
2. B) side A is hypotonic to side B.
3. C) side A is isotonic to side B.
4. D) side A is hypertonic to side B with respect to glucose.
5. E) side A is hypotonic to side B with respect to sodium chloride.

Answer: B

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

60) If you examine side A after three days, you should find

1. A) a decrease in the concentration of NaCl and glucose and an increase in the water level.
2. B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose.
3. C) no net change in the system.
4. D) a decrease in the concentration of NaCl and a decrease in the water level.
5. E) no change in the concentration of NaCl and glucose and an increase in the water level.

Answer: D

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

Use the following information to answer the questions below.

Five dialysis bags, constructed from a semipermeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.

61) Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

62) Which line in the graph represents the bag with the highest initial concentration of sucrose?

1. A) A
2. B) B
3. C) C
4. D) D
5. E) E

Answer: A

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

63) Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes?

1. A) A and B
2. B) B
3. C) C
4. D) D
5. E) D and E

Answer: B

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

Use the following information to answer the questions below.

Human immunodeficiency virus (HIV) infects cells that have both CD4 and CCR5 cell surface molecules. The viral nucleic acid molecules are enclosed in a protein capsid, and the protein capsid is itself contained inside an envelope consisting of a lipid bilayer membrane and viral glycoproteins. One hypothesis for viral entry into cells is that binding of HIV membrane glycoproteins to CD4 and CCR5 initiates fusion of the HIV membrane with the plasma membrane, releasing the viral capsid into the cytoplasm. An alternative hypothesis is that HIV gains entry into the cell via receptor-mediated endocytosis, and membrane fusion occurs in the endocytotic vesicle. To test these alternative hypotheses for HIV entry, researchers labelled the lipids on the HIV membrane with a red fluorescent dye.

64) What would be observed by live-cell fluorescence microscopy if the red fluorescent lipid dye-labelled HIV membrane fuses with the target cell plasma membrane?

1. A) A spot of red fluorescence will remain on the infected cell’s plasma membrane, marking the site of membrane fusion and HIV entry.
2. B) The red fluorescent dye-labelled lipids will diffuse in the infected cell’s plasma membrane and become difficult to detect.
3. C) A spot of red fluorescence will move into the infected cell’s cytoplasm.
4. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid.
5. E) Fluorescence microscopy does not have enough resolution to visualize fluorescently labelled HIV virus particles.

Answer: B

Type: MC

Topic: Concepts 6.1, 6.4, 7.1, 7.5

Skill: Application/Analysis

65) What would be observed by live-cell fluorescence microscopy if HIV is endocytosed first, and then fuses with the endocytotic vesicle membrane?

1. A) A spot of red fluorescence will remain on the infected cell’s plasma membrane, marking the site of membrane fusion and HIV entry.
2. B) The red fluorescent dye-labelled lipids will diffuse in the endocytotic vesicle membrane and become difficult to detect.
3. C) A spot of red fluorescence will move into the infected cell’s interior.
4. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid.
5. E) Fluorescence microscopy does not have enough resolution to visualize fluorescently labelled HIV virus particles.

Answer: C

Type: MC

Topic: Concepts 6.1, 6.4, 7.1, 7.5

Skill: Application/Analysis

66) Using live-cell fluorescence microscopy, researchers observed that a red fluorescent spot moved from the plasma membrane into the interior of target cells when red fluorescent dye-labelled HIV was added to the cells. What is the best conclusion from these observations?

1. A) The hypothesis that HIV enters the cell via fusion with the target cell plasma membrane is proved.
2. B) The hypothesis that HIV enters the cell via fusion with the target cell plasma membrane is not supported.
3. C) The hypothesis that HIV enters the cell via endocytosis is proved.
4. D) The hypothesis that HIV enters the cell via endocytosis is not supported.
5. E) Neither hypothesis is supported by these results.

Answer: B

Type: MC

Topic: Concepts 6.1, 6.4, 7.1, 7.5

Skill: Synthesis/Evaluation

67) If HIV first enters the cell in an endocytotic vesicle, instead of directly fusing with the plasma membrane, then

1. A) HIV infection should be hindered by microtubule polymerization inhibitors such as nocodazole.
2. B) HIV infection should be more efficient at lower temperatures.
3. C) intact cortical actin microfilaments should interfere with HIV infection.
4. D) cells lacking integrins should be resistant to HIV infection.
5. E) addition of ligands for other cell-surface receptors to stimulate their endocytosis should increase the efficiency of HIV infection.

Answer: A

Type: MC

Topic: Concepts 6.4, 7.5

Skill: Synthesis/Evaluation

68) In an HIV-infected cell producing HIV virus particles, the viral glycoprotein is expressed on the plasma membrane. How do the viral glycoproteins get to the plasma membrane?

1. A) They are synthesized on ribosomes on the plasma membrane.
2. B) They are synthesized by ribosomes in the rough ER, and arrive at the plasma membrane in the membrane of secretory vesicles.
3. C) They are synthesized on free cytoplasmic ribosomes, and then inserted into the plasma membrane.
4. D) They are synthesized by ribosomes in the rough ER, secreted from the cell, and inserted into the plasma membrane from the outside.
5. E) They are synthesized by ribosomes on the HIV viral membrane, which fuses with the plasma membrane from inside the cell.

Answer: B

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

Use the following information to answer the questions below.

Cystic fibrosis is a genetic disease in humans in which the CFTR protein, which functions as a chloride ion channel, is missing or nonfunctional in cell membranes.

69) The CFTR protein belongs to what category of membrane proteins?

1. A) gap junctions
2. B) aquaporins
3. C) electrogenic ion pumps
4. D) cotransporters
5. E) hydrophilic channels

Answer: C

Type: MC

Topic: Concept 7.2

Skill: Knowledge/Comprehension

70) If the sodium ion concentration outside the cell increases, and the CFTR channel is open, in what direction will chloride ions and water move across the cell membrane?

1. A) Chloride ions will move out of the cell, and water will move into the cell.
2. B) Both chloride ions and water will move out of the cell.
3. C) Chloride ions will move into the cell, and water will move out of the cell.
4. D) Both chloride ions and water will move into the cell.
5. E) The movement of chloride ions and water molecules will not be affected by changes in sodium ion concentration outside the cell.

Answer: B

Type: MC

Topic: Concept 7.2

Skill: Application/Analysis

71) In the small airways of the lung, a thin layer of liquid is needed between the epithelial cells and the mucus layer in order for cilia to beat and move the mucus and trapped particles out of the lung. One hypothesis is that the volume of this airway surface liquid is regulated osmotically by transport of sodium and chloride ions across the epithelial cell membrane. How would the lack of a functional chloride channel in cystic fibrosis patients affect sodium ion transport and the volume of the airway surface liquid?

1. A) Sodium ion transport will increase; higher osmotic potential will increase airway surface liquid volume.
2. B) Sodium ion transport will increase; higher osmotic potential will decrease airway surface liquid volume.
3. C) Sodium ion transport will decrease; lower osmotic potential will decrease airway surface liquid volume.
4. D) Sodium ion transport will decrease; lower osmotic potential will increase the airway surface liquid volume.
5. E) Sodium ion transport will be unaffected; lack of chloride transport still reduces osmotic potential and decreases the airway surface liquid volume.

Answer: C

Type: MC

Topic: Concept 7.2

Skill: Synthesis/Evaluation

72) A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water—equal to the volume of blood lost—is transferred directly into one of his veins. What will be the most probable result of this transfusion?

1. A) It will have no unfavourable effect as long as the water is free of viruses and bacteria.
2. B) The patient’s red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.
3. C) The patient’s red blood cells will swell because the blood fluid has become hypotonic compared to the cells.
4. D) The patient’s red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.
5. E) The patient’s red blood cells will burst because the blood fluid has become hypertonic compared to the cells.

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

73) You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells?

1. A) blood or tissue type of the patient
2. B) hydrophobicity of the drug molecule
3. C) lack of charge on the drug molecule
4. D) similarity of the drug molecule to other molecules transported by the target cells
5. E) lipid composition of the target cells’ plasma membrane

Answer: D

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

74) In what way do the membranes of a eukaryotic cell vary?

1. A) Phospholipids are found only in certain membranes.
2. B) Certain proteins are unique to each membrane.
3. C) Only certain membranes of the cell are selectively permeable.
4. D) Only certain membranes are constructed from amphipathic molecules.
5. E) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.

Answer: B

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

75) According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

1. A) spread in a continuous layer over the inner and outer surfaces of the membrane.
2. B) confined to the hydrophobic interior of the membrane.
3. C) embedded in a lipid bilayer.
4. D) randomly oriented in the membrane, with no fixed inside-outside polarity.
5. E) free to depart from the fluid membrane and dissolve in the surrounding solution.

Answer: C

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

76) Which of the following factors would tend to increase membrane fluidity?

1. A) a greater proportion of unsaturated phospholipids
2. B) a greater proportion of saturated phospholipids
3. C) a lower temperature
4. D) a relatively high protein content in the membrane
5. E) a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses

Answer: A

Type: MC

Topic: End-of-Chapter Questions

Skill: Knowledge/Comprehension

77) Which of the following processes includes all others?

1. A) osmosis
2. B) diffusion of a solute across a membrane
3. C) facilitated diffusion
4. D) passive transport
5. E) transport of an ion down its electrochemical gradient

Answer: D

Type: MC

Topic: End-of-Chapter Questions

Skill: Application/Analysis

78) Based on the figure above, which of these experimental treatments would increase the rate of sucrose transport into the cell?

1. A) decreasing extracellular sucrose concentration
2. B) decreasing extracellular pH
3. C) decreasing cytoplasmic pH
4. D) adding an inhibitor that blocks the regeneration of ATP
5. E) adding a substance that makes the membrane more permeable to hydrogen ions

Answer: B

Type: MC

Topic: End-of-Chapter Questions

Skill: Application/Analysis

79) What will happen to a red blood cell (RBC), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of pure water?

1. A) The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.
2. B) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC.
3. C) The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.
4. D) The cell will remain the same size because the solution outside the cell is isotonic.
5. E) The cell will remain the same size because the solution outside the cell is hypotonic.

Answer: C

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

80) Which of the following correctly describes the function of the sodium-potassium pump?

1. A) moves three potassium ions out of a cell and two sodium ions into a cell while producing an ATP in each cycle
2. B) moves three sodium ions out of a cell and two potassium ions into a cell while consuming an ATP in each cycle
3. C) moves three potassium ions out of a cell and two sodium ions into a cell while consuming 2 ATP in each cycle
4. D) moves three sodium ions out of a cell and two potassium ions into a cell and while producing an ATP in each cycle
5. E) moves three sodium ions out of a cell and three potassium ions into a cell and producing an ATP in each cycle

Answer: B

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

81) What is the force driving simple diffusion and energy source for active transport, respectively?

1. A) the concentration gradient; ADP
2. B) the concentration gradient; ATP
3. C) transmembrane pumps; electron transport
4. D) phosphorylated protein carriers; ATP
5. E) proton gradient; ADP

Answer: B

Type: MC

Topic: Concept 7.4

Skill: Knowledge/Comprehension

82) Three lab groups carried out an experiment to identify the correct molarities for five solutions. Each unknown contained one of the following sucrose concentrations: 0.0 M, 0.2 M, 0.4 M, 0.6 M, 0.8 M, and 1.0 M. Each data entry represents the average of 3 sample replications of 1 cm3 sweet potato cubes expressed as percent change in mass after an overnight (24 hr) soak in the unknown solutions. From the data given, which statement most accurately describes what is occurring in response to a particular unknown solution.

1. A) Unknown solution E contains the highest concentration of sucrose and the change in mass is due to the active transport of sucrose into the cell in exchange for water molecules.
2. B) Osmosis of water molecules from unknown solution A likely caused the increase in mass observed.
3. C) Passive transport of sucrose out of the potato cells explains the change in mass observed for unknown solution F.
4. D) Unknown solution C represents a sucrose molarity slightly lower than the molarity of sweet potato cells, thus water is transported out of the cells.
5. E) Transport of Na+ to the outside of the cell is likely have caused the decrease in mass observed for unknown solution C.

Answer: B

Type: MC

Topic: Concept 7.3

Skill: Application/Analysis

83) Fibronectin binds to integrin, an integral plasma membrane protein. Binding of fibronectin to the extracellular domain of integrin changes integrin’s conformation. The change in protein conformation is transmitted to the cytoplasm resulting in a cascade of reactions. What does this description describe?

1. A) transport
2. B) enzymatic activity
3. C) intracellular joining
4. D) cell-cell recognition
5. E) signal transduction

Answer: E

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

84) Which correctly describes intracellular joining?

1. A) long-lasting interaction between two adjacent cells
2. B) short-lived interaction between membrane protein on one cell and carbohydrate on another cell
3. C) fusion of the plasma membranes between two adjacent cells
4. D) fusion of intracellular membrane with plasma membrane of the same cell
5. E) joining of microfilaments with extracellular matrix

Answer: A

Type: MC

Topic: Concept 7.1

Skill: Application/Analysis

85) What does a ribbon diagram show?

1. A) nucleic acid backbone
2. B) protein backbone
3. C) carbohydrate backbone
4. D) lipid backbone
5. E) hydrocarbon backbone

Answer: B

Type: MC

Topic: Concept 7.1

Skill: Knowledge/Comprehension

86) What do contractile vacuoles in Paramecium assist with?

1. A) osmoregulation
2. B) selective uptake
3. C) endocytosis
4. D) digestion
5. E) water storage

Answer: A

Type: MC

Topic: Concept 7.3

Skill: Knowledge/Comprehension

87) An organism non-selectively takes in droplets of water and small molecules. What is this process called?

1. A) receptor-mediated endocytosis
2. B) pinocytosis
3. C) phagocytosis
4. D) cotransport
5. E) facilitated diffusion

Answer: B

Type: MC

Topic: Concept 7.5

Skill: Knowledge/Comprehension

88) Which of the following processes requires energy?

1. A) diffusion
2. B) facilitated diffusion
3. C) transport through channels
4. D) osmosis
5. E) pinocytosis

Answer: E

Type: MC

Topic: Concepts 7.3, 7.5

Skill: Knowledge/Comprehension