1. A Tour of the Cell

2. Which cellular structure is common to all three domains of life?
nucleus
endoplasmic reticulum
mitochondria
phospholipid bilayer cell membrane
endocytotic vesicles
Answer: D

3. Which cellular structure is common to all three domains of life?
nucleus
endoplasmic reticulum
mitochondria
phospholipid bilayer cell membrane
endocytotic vesicles 3

4. Enzymes responsible for biosynthesis of membrane lipids are located in what part of an animal cell?
endoplasmic reticulum
nucleus
lysosomes
Golgi
plasma membrane
Answer: A 4

5. Enzymes responsible for biosynthesis of membrane lipids are located in what part of an animal cell?
endoplasmic reticulum
nucleus
lysosomes
Golgi
plasma membrane 5

6. Which of the following is not an argument for the theory that mitochondria and chloroplasts evolved from prokaryotic endosymbionts?
Mitochondria and chloroplasts have double membranes.
Mitochondria and chloroplasts have their own ribosomes.
Mitochondria and chloroplasts have their own DNA.
The mitochondrial and chloroplast genomes are circular.
Both the matrix and stromal spaces of these organelles contain many types of soluble proteins.
Answer: E 6

7. Which of the following is not an argument for the theory that mitochondria and chloroplasts evolved from prokaryotic endosymbionts?
Mitochondria and chloroplasts have double membranes.
Mitochondria and chloroplasts have their own ribosomes.
Mitochondria and chloroplasts have their own DNA.
The mitochondrial and chloroplast genomes are circular.
Both the matrix and stromal spaces of these organelles contain many types of soluble proteins. 7

8. Autophagy removes old damaged organelles like mitochondria
Autophagy removes old damaged organelles like mitochondria. Decreased autophagy results in degeneration and inflammation and may result in the “symptoms” of aging. Which of the following choices is most directly involved in the process of autophagy?
smooth ER
peroxisomes
rough ER
lysosomes
Golgi apparatus
Answer: D
This question covers a hot area of research and involves application of information on lysosomes. 8

9. Autophagy removes old damaged organelles like mitochondria
Autophagy removes old damaged organelles like mitochondria. Decreased autophagy results in degeneration and inflammation and may result in the “symptoms” of aging. Which of the following choices is most directly involved in the process of autophagy?
smooth ER
peroxisomes
rough ER
lysosomes
Golgi apparatus 9

10. What proteins are not made at the rough ER?
insulin (a secreted proteinaceous hormone)
digestive enzymes of the gut
antibodies in the blood
proteins that enter the nucleus and bind there with the DNA as part of the chromatin
collagen (an extracellular matrix protein)
Answer: D 10

11. What proteins are not made at the rough ER?
insulin (a secreted proteinaceous hormone)
digestive enzymes of the gut
antibodies in the blood
proteins that enter the nucleus and bind there with the DNA as part of the chromatin
collagen (an extracellular matrix protein) 11

12. What is the correct order of the exocytosis or secretion pathway?
rough ER, endosome, Golgi, smooth ER
rough ER, Golgi, smooth ER, plasma membrane
smooth ER, rough ER, exocytosis, Golgi
rough ER, Golgi, transport vesicle, plasma membrane
rough ER, Golgi, endosome, plasma membrane, transport vesicle
Answer: D 12

13. What is the correct order of the exocytosis or secretion pathway?
rough ER, endosome, Golgi, smooth ER
rough ER, Golgi, smooth ER, plasma membrane
smooth ER, rough ER, exocytosis, Golgi
rough ER, Golgi, transport vesicle, plasma membrane
rough ER, Golgi, endosome, plasma membrane, transport vesicle 13

14. Brefeldin A is a drug that disrupts transport from the ER to the Golgi apparatus. What other organelles and membranes in an animal cell are affected?
lysosomes, transport vesicles, plasma membrane, nuclear membranes
mitochondria, peroxisomes, plasma membrane
vacuoles, mitochondria, plasma membrane
lysosomes, transport vesicles, nuclear membrane
all intracellular organelles and membranes
Answer: A
This question addresses student understanding of membrane flow and the continuity of the endomembrane system. 14

15. Brefeldin A is a drug that disrupts transport from the ER to the Golgi apparatus. What other organelles and membranes in an animal cell are affected?
lysosomes, transport vesicles, plasma membrane, nuclear membranes
mitochondria, peroxisomes, plasma membrane
vacuoles, mitochondria, plasma membrane
lysosomes, transport vesicles, nuclear membrane
all intracellular organelles and membranes 15

16. Alcohol is destroyed in the cell by the removal of hydrogen atoms
Alcohol is destroyed in the cell by the removal of hydrogen atoms. Where does this occur? (Drugs are destroyed in the cell at a different location.)
lysosome
smooth ER
peroxisome
rough ER
Golgi apparatus
Answer: C
This is important/interesting information to students. The question includes information to remind students of hydroxylation of drugs at the smooth ER. 16

17. Alcohol is destroyed in the cell by the removal of hydrogen atoms
Alcohol is destroyed in the cell by the removal of hydrogen atoms. Where does this occur? (Drugs are destroyed in the cell at a different location.)
lysosome
smooth ER
peroxisome
rough ER
Golgi apparatus 17

18. Taxol, a drug approved for the treatment of breast cancer, prevents depolymerization of microtubules. What cellular function that affects cancer cells more than normal cells might Taxol interfere with?
maintaining cell shape
cell motility (cilia or flagella)
chromosome movements in cell division
cell division (cleavage furrow formation)
cytoplasmic streaming
Answer: C
This question relates the cytoskeleton to cell division and cancer. It emphasizes that cytoskeletal elements have to be dynamic: Freezing the microtubules prevents the dynamic microtubule rearrangements, growth, and depolymerization required for cell division. It asks students to think about the differences between cancer cells and normal cells. 18

19. Taxol, a drug approved for the treatment of breast cancer, prevents depolymerization of microtubules. What cellular function that affects cancer cells more than normal cells might Taxol interfere with?
maintaining cell shape
cell motility (cilia or flagella)
chromosome movements in cell division
cell division (cleavage furrow formation)
cytoplasmic streaming 19

20. Many types of polysaccharides (such as glucosamine, chondroitin, and hyaluronate) are sold in health-food and grocery stores to help reduce pain and increase flexibility in the joints. They are molecules that make up
collagen of extracellular matrix.
proteoglycan complex of extracellular matrix.
integrins.
fibronectin.
cytoskeleton.
Answer: B 20

21. Many types of polysaccharides (such as glucosamine, chondroitin, and hyaluronate) are sold in health-food and grocery stores to help reduce pain and increase flexibility in the joints. They are molecules that make up
collagen of extracellular matrix.
proteoglycan complex of extracellular matrix.
integrins.
fibronectin.
cytoskeleton. 21

22. In the figure on the next slide, centrifugation-based fractionation of cellular contents is shown, with tubes at stages A–E noted. If you wished to study the cytosolic protein actin, which sample would be the best to use as a source of this item?
the pellet of tube B
the supernatant of tube E
the supernatant of tube A
the pellet of tube C
the pellet of tube E
Answer: B

23. A B C D E

24. In the figure on the previous slide, centrifugation-based fractionation of cellular contents is shown, with tubes at stages A–E noted. If you wished to study the cytosolic protein actin, which sample would be the best to use as a source of this item?
the pellet of tube B
the supernatant of tube E
the supernatant of tube A
the pellet of tube C
the pellet of tube E

25. In the figure on the next slide, centrifugation-based fractionation of cellular contents is shown, with tubes at stages A–E noted. If you examine the various pellets from these different tubes, which organelle are you least likely to be able to detect by light microscopy?
nuclei
individual starch grains
chloroplasts
mitochondria
ribosomes
Answer: E

26. A B C D E

27. In the figure on the previous slide, centrifugation-based fractionation of cellular contents is shown, with tubes at stages A–E noted. If you examine the various pellets from these different tubes, which organelle are you least likely to be able to detect by light microscopy?
nuclei
individual starch grains
chloroplasts
mitochondria
ribosomes

28. Of the images at the right, which shows the best resolution?D E A B C
Answer: E D E

29. Of the images at the right, which shows the best resolution?D E A B C D E

30. Of the images at the right, which are most likely to be dead and preserved material?
A and C
E and B
D and A
C and D
E and C A B C
Answer: B D E

31. Of the images at the right, which are most likely to be dead and preserved material?
A and C
E and B
D and A
C and D
E and C A B C D E

32. Which choice best explains the effect of the presence of a large central vacuole, as found in many plant cells (see image on next slide), on the cell surface area required to obtain the items needed for the metabolic activities of such a cell?
The presence of a central vacuole shifts the more active cytoplasmic areas closer to the plasma membrane, which, being then at a lower distance from the outer member, places less of a burden on the outer cell surface area.
The vacuole is a very metabolically active compartment, so the cell needs more surface area to service this extra volume.
A large central vacuole can provide all the items needed by the rest of the cell; therefore, a high external cell surface area is not needed.
Constructing and maintaining the central vacuole places significant metabolic demands on the cell, this creates a need for a higher cell surface area.
The vacuole increases the total volume of the cell, so the need for a greater cell surface area increases.
Answer: A

34. Which choice best explains the effect of the presence of a large central vacuole, as found in many plant cells, on the cell surface area required to obtain the items needed for the metabolic activities of such a cell?
The presence of a central vacuole shifts the more active cytoplasmic areas closer to the plasma membrane, which, being then at a lower distance from the outer member, places less of a burden on the outer cell surface area.
The vacuole is a very metabolically active compartment, so the cell needs more surface area to service this extra volume.
A large central vacuole can provide all the items needed by the rest of the cell; therefore, a high external cell surface area is not needed.
Constructing and maintaining the central vacuole places significant metabolic demands on the cell, this creates a need for a higher cell surface area.
The vacuole increases the total volume of the cell, so the need for a greater cell surface area increases.

35. In a typical eukaryotic cell the surface area to volume ratios of the endoplasmic reticulum relative to the cytosol volume, the inner membrane of the mitochondria relative to the matrix volume, and the thylakoid membranes relative to the stomal volume in the chloroplast are all high. This implies that
there is less need for a high surface area at the cell membrane to service these areas.
these compartments are more essential than the nuclear compartment with its relatively lower surface area to volume ratio.
the total volume of these compartments is kept low in most cells.
all these compartments are very metabolically active and need high exchange surface areas inside the cell to support their activities.
this extra internal membrane area acts to keep each of these compartments distinct from the surrounding ones.
Answer: D

36. In a typical eukaryotic cell the surface area to volume ratios of the endoplasmic reticulum relative to the cytosol volume, the inner membrane of the mitochondria relative to the matrix volume, and the thylakoid membranes relative to the stomal volume in the chloroplast are all high. This implies that
there is less need for a high surface area at the cell membrane to service these areas.
these compartments are more essential than the nuclear compartment with its relatively lower surface area to volume ratio.
the total volume of these compartments is kept low in most cells.
all these compartments are very metabolically active and need high exchange surface areas inside the cell to support their activities.
this extra internal membrane area acts to keep each of these compartments distinct from the surrounding ones.
Answer: D

37. A typical eukaryotic nucleus has to exchange a great deal of protein and nucleic acid material with the surrounding cytosol of the cell. Which choice correctly describes a feature of most nuclei that helps promote this exchange?
Many nuclei wait until the start of cell division, when the nuclear membrane barriers are removed, for the exchange of many needed items.
There are numerous nuclear pores that allow regulated passage of selected items into and out of the nuclear space.
Large numbers of vesicles that fuse with and bleb from the nuclear membranes are used in the movement of these items.
Many nuclei increase their membrane surface area relative to the nuclear volume by modifying their shape from that of a sphere.
The nuclear envelope membranes are selectively permeable and able to permit the passage of the needed items through their lipid phase.
Answer: B

38. A typical eukaryotic nucleus has to exchange a great deal of protein and nucleic acid material with the surrounding cytosol of the cell. Which choice correctly describes a feature of most nuclei that helps promote this exchange?
Many nuclei wait until the start of cell division, when the nuclear membrane barriers are removed, for the exchange of many needed items.
There are numerous nuclear pores that allow regulated passage of selected items into and out of the nuclear space.
Large numbers of vesicles that fuse with and bleb from the nuclear membranes are used in the movement of these items.
Many nuclei increase their membrane surface area relative to the nuclear volume by modifying their shape from that of a sphere.
The nuclear envelope membranes are selectively permeable and able to permit the passage of the needed items through their lipid phase.

39. A membrane protein is made and inserted into the membrane of the rough endoplasmic reticulum. A binding site that is present in this protein is aligned so that it faces the lumen of the ER. If this protein is then moved to other endomembranes, at which surface of the membranes given below is this binding site unlikely to be found?
the internal face of the Golgi apparatus membranes
the internal face of a lysosome membrane
facing the intermembrane space of the nuclear envelope membranes
the lumen face of a vesicle just derived from the Golgi apparatus
the cytosolic face of the plasma membrane
Answer: E

40. A membrane protein is made and inserted into the membrane of the rough endoplasmic reticulum. A binding site that is present in this protein is aligned so that it faces the lumen of the ER. If this protein is then moved to other endomembranes, at which surface of the membranes given below is this binding site unlikely to be found?
the internal face of the Golgi apparatus membranes
the internal face of a lysosome membrane
facing the intermembrane space of the nuclear envelope membranes
the lumen face of a vesicle just derived from the Golgi apparatus
the cytosolic face of the plasma membrane

41. Which compartments of the mitochondria and the chloroplasts are most similar to the cytosol of a eukaryotic cell?
the mitochondrial intermembrane space and the lumen of the thylakoids
the mitochondrial intermembrane space and the stromal space
the matrix space and the stromal space
the matrix space and the lumen of the thylakoids
the matrix space and the interenvelope space of the chloroplast
Answer: C

42. Which compartments of the mitochondria and the chloroplasts are most similar to the cytosol of a eukaryotic cell?
the mitochondrial intermembrane space and the lumen of the thylakoids
the mitochondrial intermembrane space and the stromal space
the matrix space and the stromal space
the matrix space and the lumen of the thylakoids
the matrix space and the interenvelope space of the chloroplast

43. A eukaryotic cell carries out phagocytosis and engulfs a bacterial cell, which ends up in the resulting food vacuole. To go from the cytosol of this bacterial cell to outside of the eukaryotic cell that has taken it in, what is the least number of biological membranes that would have to be crossed? 2 4 1 5 3
Answer: E

44. A eukaryotic cell carries out phagocytosis and engulfs a bacterial cell, which ends up in the resulting food vacuole. To go from the cytosol of this bacterial cell to outside of the eukaryotic cell that has taken it in, what is the least number of biological membranes that would have to be crossed? 2 4 1 5 3

45. Which one of the following is not a common feature of the microfilament and microtubule fibers of the cytoskeleton?
Often there are distinct types of motor proteins that interact with each type of fiber.
Both make up part of the elements present in basal bodies.
The actin and tubulin subunits in these fibers are coded for by genes in the nucleus.
Both fibers can be in a stable state or can also be in a dynamic state of turnover.
The subunits assemble into each fiber interact using noncovalent interactions.
Answer: B

46. Which one of the following is not a common feature of the microfilament and microtubule fibers of the cytoskeleton?
Often there are distinct types of motor proteins that interact with each type of fiber.
Both make up part of the elements present in basal bodies.
The actin and tubulin subunits in these fibers are coded for by genes in the nucleus.
Both fibers can be in a stable state or can also be in a dynamic state of turnover.
The subunits assemble into each fiber interact using noncovalent interactions.
Answer: B

47. On the next slide is a figure showing some of the sizes of biologically relevant items. If the extracellular matrix of animals and the cell walls of plants and fungi are to give any protection to the cell from pathogenic microbes and viruses that attempt to enter the cell, then the pores in these extracellular structures should be roughly what diameter?
1 nm
5 nm
40 nm
1 μm
100 μm
Answer: C

49. If the extracellular matrix of animals and the cell walls of plants and fungi are to give any protection to the cell from pathogenic microbes and viruses that attempt to enter the cell, then the pores in these extracellular structures should be roughly what diameter?
1 nm
5 nm
40 nm
1 μm
100 μm
Answer: C

50. Cells need many items to be viable, but across the diversity of cells there are many variable items that are not essential. Which of the following items is least essential to a cell and so can be absent from the cells of some species?
mitochondria
plasma membrane
ribosomes
proteins
genetic material
Answer: A

51. Cells need many items to be viable, but across the diversity of cells there are many variable items that are not essential. Which of the following items is least essential to a cell and so can be absent from the cells of some species?
mitochondria
plasma membrane
ribosomes
proteins
genetic material