1) The smallest cell structure that would most likely be visible with a standard (not super- resolution) research-grade light microscope is a _____.
A) mitochondrion
B) microtubule

C) ribosome
D) microfilament

Answer: A

2) The advantage of light microscopy over electron microscopy is that _____.
A) light microscopy provides for higher magnification than electron microscopy

B) light microscopy provides for higher resolving power than electron microscopy C) light microscopy allows one to view dynamic processes in living cells
D) light microscopy provides higher contrast than electron microscopy

Answer: C

3) 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 the _____.
A) relative solubility of the component
B) size and weight of the component
C) percentage of carbohydrates in the component
D) presence or absence of lipids in the component

Answer: B

4) What is the reason that a modern transmission 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?
A) The focal length of the electron microscope is significantly longer.
B) Contrast is enhanced by staining with atoms of heavy metal.
C) Electron beams have much shorter wavelengths than visible light.
D) The electron microscope has a much greater ratio of image size to real size.

Answer: C

5) What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?
A) standard light microscopy
B) scanning electron microscopy

C) transmission electron microscopy

Answer: A

6) A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab. What is the primary reason for the price difference?
A) The toy microscope does not have the same fine control for focus of the specimen.

B) The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.
C) The college microscope produces greater contrast in the specimens.
D) The toy microscope usually uses a different wavelength of light source.

Answer: B

7) All of the following are part of a prokaryotic cell EXCEPT _____.

A) a cell wall
B) a plasma membrane
C) ribosomes

D) an endoplasmic reticulum

Answer: D

8) Cell size is limited by _____.
A) the number of proteins within the plasma membrane

B) the surface area of mitochondria in the cytoplasm

C) surface to volume ratios
D) the size of the endomembrane system

Answer: C

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

A) Prokaryotes have cells while eukaryotes do not.
B) Eukaryotic cells have more intracellular organelles than prokaryotes.
C) Prokaryotes are not able to carry out aerobic respiration, relying instead on anaerobic metabolism.

D) Prokaryotes are generally larger than eukaryotes.

Answer: B

10) 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?
A) Pinch the edges of the cube into small folds.
B) Flatten the cube into a pancake shape.

C) Round the clay up into a sphere.
D) Stretch the cube into a long, shoebox shape.

Answer: C

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

A) Bacteria and Eukarya
B) Bacteria and Archaea
C) Archaea and Protista

D) Bacteria and Protista

Answer: B

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

A) chloroplast
B) central vacuole
C) mitochondrion

D) centriole

Answer: C

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

A) mitochondrion
B) ribosome
C) chloroplast

D) ER

Answer: B

14) In a bacterium, we will find DNA in _____.

A) a membrane-enclosed nucleus
B) mitochondria
C) the nucleoid

D) ribosomes

Answer: C

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

A) mitochondria
B) microtubules
C) centrosomes

D) peroxisomes

Answer: C

16) What is the function of the nuclear pore complex found in eukaryotes?
A) It regulates the movement of proteins and RNAs into and out of the nucleus.
B) It synthesizes the proteins required to copy DNA and make mRNA.
C) It selectively transports molecules out of the nucleus, but prevents all inbound molecules from entering the nucleus.
D) It assembles ribosomes from raw materials that are synthesized in the nucleus.

Answer: A

17) Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane?
A) DNA
B) amino acids

C) mRNA
D) phospholipids

Answer: C

18) Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?
A) Prokaryotes cannot secrete proteins because they lack an endomembrane system.
B) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.

C) Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.

D) Prokaryotes cannot secrete proteins because they lack ribosomes.

Answer: C

19) Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
A) lipids
B) glycogen

C) proteins
D) nucleic acids

Answer: C

20) 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 most likely expect to be the immediate consequence?
A) the loss of all nuclear function

B) the inability of the nucleus to divide during cell division

C) a change in the shape of the nucleus
D) failure of chromosomes to carry genetic information

Answer: C

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

A) primarily producing proteins for secretion
B) primarily producing proteins in the cytosol
C) constructing an extensive cell wall or extracellular matrix

D) enlarging its vacuole

Answer: B

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

A) lysosome
B) vacuole
C) Golgi apparatus

D) peroxisome

Answer: B

23) A cell with an extensive area of smooth endoplasmic reticulum is specialized to _____.

A) play a role in storage
B) synthesize large quantities of lipids
C) actively export protein molecules

D) import and export protein molecules

Answer: B

24) Which structure is NOT part of the endomembrane system?

A) nuclear envelope
B) chloroplast
C) Golgi apparatus

D) plasma membrane

Answer: B

25) The Golgi apparatus has a polarity, or sidedness, to its structure and function. Which of the following statements correctly describes this polarity?
A) Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
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.

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.
D) All of the listed responses correctly describe polarity characteristics of the Golgi function.

Answer: D

26) The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by the _____.
A) transportation of membrane lipids among the membranes of the endomembrane system by small membrane vesicles
B) function of the Golgi apparatus in sorting and directing membrane components
C) modification of the membrane components once they reach their final destination
D) synthesis of different lipids and proteins in each of the organelles of the endomembrane system

Answer: B

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

A) rough ER
B) plasmodesmata
C) Golgi vesicles

D) free cytoplasmic ribosomes

Answer: A

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

B) the Golgi apparatus

C) the lysosome
D) mitochondrion

Answer: C

29) 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?
A) rough ER
B) smooth ER

C) Golgi apparatus
D) nuclear envelope

Answer: B

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

A) lysosome
B) mitochondrion
C) Golgi apparatus

D) peroxisome

Answer: C

31) What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?
A) ER → Golgi → nucleus
B) Golgi → ER → lysosome

C) ER → Golgi → vesicles that fuse with plasma membrane
D) ER → lysosomes → vesicles that fuse with plasma membrane

Answer: C

32) 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 caused by the inhalation of asbestos fibers. Cells will phagocytize asbestos, but are not able to degrade it. As a result, asbestos fibers accumulate in _____.

A) mitochondria
B) ribosomes
C) peroxisomes
D) lysosomes

Answer: D

33) Which of the following is NOT true? Both chloroplasts and mitochondria _____.

A) have their own DNA
B) have multiple membranes
C) are part of the endomembrane system

D) are capable of reproducing themselves

Answer: C

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

A) lysosome
B) mitochondrion
C) Golgi apparatus

D) peroxisome

Answer: B

35) Thylakoids, DNA, and ribosomes are all components found in _____.

A) chloroplasts
B) mitochondria
C) lysosomes

D) nuclei

Answer: A

36) In a plant cell, DNA may be found _____.
A) only in the nucleus
B) only in the nucleus and chloroplasts
C) in the nucleus, mitochondria, and chloroplasts
D) in the nucleus, mitochondria, chloroplasts, and peroxisomes

Answer: C

37) In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and _____.
A) combine the hydrogen with water molecules to generate hydrogen peroxide
B) use the hydrogen to break down hydrogen peroxide

C) transfer the hydrogen to the mitochondria
D) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide

Answer: D

38) The evolution of eukaryotic cells most likely involved _____.
A) endosymbiosis of an aerobic bacterium in a larger host cell—the endosymbiont evolved into mitochondria
B) anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygen—the anaerobic bacterium evolved into chloroplasts
C) an endosymbiotic fungal cell evolving into the nucleus
D) acquisition of an endomembrane system and subsequent evolution of mitochondria from a portion of the Golgi

Answer: A

39) Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the ER?
A) in the extracellular matrix
B) in the Golgi apparatus

C) in mitochondria
D) in the nucleolus

Answer: C

40) Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from _____.
A) a bacterium
B) an animal but not a plant

C) nearly any eukaryotic organism
D) a plant but not an animal

Answer: C

41) 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 _____.
A) mitochondria
B) peroxisomes

C) lysosomes
D) endoplasmic reticulum

Answer: A

42) Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely involved in this disease?
A) lysosomes
B) Golgi apparatus

C) ribosomes
D) mitochondria

Answer: D

43) Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
A) membrane proteins of the inner nuclear envelope
B) free ribosomes and ribosomes attached to the ER

C) components of the cytoskeleton
D) cellulose fibers in the cell wall

Answer: C

44) Which of the following contain the 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules?
A) motile cilia and primary (nonmotile) cilia
B) flagella and motile cilia

C) basal bodies and primary (nonmotile) cilia
D) centrioles and basal bodies

Answer: B

45) Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____.
A) form cleavage furrows during cell division
B) migrate by amoeboid movement

C) separate chromosomes during cell division D) maintain the shape of the nucleus

Answer: C

46) Amoebae move by crawling over a surface (cell crawling), which involves _____.
A) growth of actin filaments to form bulges in the plasma membrane
B) setting up microtubule extensions that vesicles can follow in the movement of cytoplasm

C) reinforcing the pseudopod with intermediate filaments
D) cytoplasmic streaming

Answer: A

47) 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?
A) an axon
B) contractile microfilaments
C) endoplasmic reticulum
D) motor proteins

Answer: D

48) Cilia and flagella bend because of _____.
A) conformational changes in ATP that thrust microtubules laterally

B) a motor protein called radial spokes
C) the quick inward movements of water by osmosis.
D) a motor protein called dynein

Answer: D

49) 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?
A) abnormally shaped RBCs
B) an insufficient supply of ATP in the RBCs

C) an insufficient supply of oxygen-transporting proteins in the RBCs

D) adherence of RBCs to blood vessel walls, causing plaque formation

Answer: A

50) Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to _____.
A) divide in two
B) contract muscle fibers

C) extend pseudopodia
D) move vesicles within a cell

Answer: D

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

A) tubulin
B) laminin
C) actin

D) intermediate filaments

Answer: A

52) Which of the following statements about the cytoskeleton is true?
A) The cytoskeleton of eukaryotes is a static structure most resembling scaffolding used at construction sites.
B) Although microtubules are common within a cell, actin filaments are rarely found outside of the nucleus.
C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
D) Chemicals that block the assembly of the cytoskeleton would have little effect on a cell's response to external stimuli.

Answer: C

53) 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?
A) They must block water and small molecules to regulate the exchange of matter and energy with their environment.

B) They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume.
C) They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell.

D) They are composed of a mixture of lipids and nucleotides.

Answer: C

54) A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its _____.
A) nuclear matrix and extracellular matrix
B) mitochondria and Golgi apparatus

C) Golgi apparatus and extracellular matrix

D) nuclear pores and secretory vesicles

Answer: C

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

A) gap junctions
B) the nucleus

C) DNA and RNA
D) integrins

Answer: D

56) Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
A) desmosomes
B) gap junctions

C) extracellular matrix
D) tight junctions

Answer: B

57) Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through _____.
A) plasmodesmata
B) tight junctions

C) desmosomes
D) gap junctions

Answer: D

58) In plant cells, the middle lamella _____.
A) allows adjacent cells to adhere to one another
B) prevents dehydration of adjacent cells
C) maintains the plant's circulatory system
D) allows for gas and nutrient exchange among adjacent cells

Answer: A

59) Where would you expect to find tight junctions?
A) in the epithelium of an animal's stomach
B) between the smooth endoplasmic reticulum and the rough endoplasmic reticulum

C) between plant cells in a woody plant
D) in the plasma membrane of prokaryotes

Answer: A

60) H. V. Wilson worked with sponges to gain some insight into exactly 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?
A) The two species of sponge had different enzymes that functioned in the reassembly process.

B) The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment.
C) The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.
D) One cell functioned as the nucleus for each organism, thereby attracting only cells of the same pigment.

Answer: C

61) 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.
A) The mitochondria are most likely defective and do not produce adequate amounts of ATP needed for cellular respiration.

B) The rough endoplasmic reticulum contains too many ribosomes which results in an overproduction of the enzyme involved in carbohydrate catalysis.
C) The lysosomes lack sufficient amounts of enzymes necessary for the metabolism of lipids.

D) The Golgi apparatus produces vesicles with faulty membranes that leak their contents into the cytoplasm of the cell.

Answer: C