Download Cell Biology Quiz: Membrane Transport, Cell Signaling, and Cancer Biology - Prof. Crousill and more Study notes Physiology in PDF only on Docsity!
1. The fluid mosaic model of the cell membrane is described as: โ A) Static and rigid โ B) Fluid with proteins and carbohydrates inserted into a bilayer โ C) Impermeable to all molecules โ D) A rigid bilayer of carbohydrates and lipids 2. Which type of molecules can freely diffuse across the plasma membrane? โ A) Large, polar molecules โ B) Ions like sodium and potassium โ C) Small, nonpolar molecules โ D) Protein 3. In the context of membrane transport, passive transport refers to: โ A) Transport that requires energy โ B) The movement of molecules from low to high concentration โ C) The movement of molecules from high to low concentration without energy โ D) The active pumping of ions across a membrane 4. Which process describes the movement of water from a region of low solute concentration to high solute concentration? โ A) Facilitated diffusion โ B) Active transport โ C) Osmosis โ D) Endocytosis 5. What determines the resting membrane potential (RMP) in most cells? โ A) Equal distribution of ions across the membrane โ B) The movement of sodium and potassium ions โ C) ATP hydrolysis โ D) The absence of ion channels
6. The chemical driving force for sodium (Na+) across the membrane always pushes sodium: โ A) Into the cell โ B) Out of the cell โ C) Both into and out of the cell simultaneously โ D) Sodium has no chemical driving force 7. What is the equilibrium potential for potassium (K+)? โ A) +55 mV โ B) -70 mV โ C) -94 mV โ D) 0 mV 8. In the electrochemical force, the sum of the electrical and chemical forces determines: โ A) The rate of osmosis โ B) The direction and strength of ion movement โ C) The thickness of the membrane โ D) The breakdown of ATP 9. Sodium-potassium ATPase pumps function by: โ A) Moving 3 Na+ ions into the cell and 2 K+ ions out โ B) Moving 2 Na+ ions out of the cell and 3 K+ ions in โ C) Moving 3 Na+ ions out of the cell and 2 K+ ions in โ D) Moving 2 Na+ ions into the cell and 3 K+ ions out 10. What is the purpose of the sodium-potassium pump? โ A) To transport large molecules across the membrane โ B) To maintain higher concentrations of K+ inside the cell and Na+ outside โ C) To generate energy for the cell โ D) To make the cell membrane thicker 11. Which of the following is a type of passive transport?
โ C) ATP hydrolysis โ D) Breakdown of membrane proteins
17. What type of chemical messenger requires direct physical contact between cells to communicate? โ A) Paracrine โ B) Hormonal โ C) Direct intercellular communication โ D) Endocrine signaling 18. What is the main difference between hydrophilic and hydrophobic messengers in endocrine signaling? โ A) Hydrophilic messengers dissolve in water, hydrophobic ones repel water โ B) Hydrophilic messengers require ATP, hydrophobic ones do not โ C) Hydrophobic messengers are stored in the nucleus, hydrophilic in the membrane โ D) Hydrophobic messengers dissolve in blood, while hydrophilic ones bind to carrier proteins 19. Which molecules can pass freely through the membrane due to their nonpolar nature? โ A) Steroid hormones โ B) Ions โ C) Proteins โ D) Glucose 20. Which of the following describes the role of ligands in cellular communication? โ A) They are enzymes that break down proteins โ B) They bind to receptor proteins to initiate a response โ C) They act as cell transporters โ D) They are structural proteins in the membrane 21. Which form of drug tolerance occurs when the body becomes better at metabolizing a drug? โ A) Pharmacokinetic tolerance
โ B) Pharmacodynamic tolerance โ C) Endocytotic tolerance โ D) Agonistic tolerance
22. G-protein coupled receptors (GPCRs) can regulate: โ A) Only ion channels โ B) Only enzyme pathways โ C) Ion channels and enzyme pathways โ D) DNA replication 23. Which type of cancer-causing genes are responsible for promoting cell division under normal conditions? โ A) Tumor suppressor genes โ B) Oncogenes โ C) Proto-oncogenes โ D) Caretaker genes 24. Tumor-suppressor genes: โ A) Promote uncontrollable cell division โ B) Help repair damaged DNA โ C) Prevent cells with damaged DNA from dividing โ D) Cause mutations in healthy cells 25. Which virus is linked to causing the majority of cervical cancers? โ A) HIV โ B) Hepatitis B โ C) Human papillomavirus (HPV) โ D) Epstein-Barr virus 26. How does the HPV virus promote cancer development? โ A) It increases the replication of healthy cells โ B) It inhibits tumor-suppressor genes such as p
โ D) +30 mV
32. Which process directly uses ATP to transport ions against their gradient? โ A) Facilitated diffusion โ B) Secondary active transport โ C) Primary active transport โ D) Osmosis 33. What is the major difference between cotransport and countertransport in secondary active transport? โ A) Cotransport moves ions in opposite directions, countertransport moves ions in the same direction. โ B) Cotransport moves two molecules in the same direction, countertransport moves molecules in opposite directions. โ C) Cotransport requires ATP, while countertransport does not. โ D) Countertransport requires carrier proteins, while cotransport does not. 34. What happens to a cell in a hypotonic solution? โ A) It shrinks as water leaves the cell. โ B) It remains the same size as no water moves. โ C) It swells as water enters the cell. โ D) It bursts due to the movement of ions into the cell. 35. Which of the following is an example of receptor-mediated endocytosis? โ A) Random uptake of water into the cell โ B) Binding of a specific hormone to a receptor followed by internalization โ C) Uptake of large particles like bacteria โ D) Movement of ions across a protein channel 36. What role does the viral protein E6 play in the development of HPV-related cancer? โ A) It promotes DNA replication. โ B) It inhibits the tumor suppressor protein p53.
โ C) It enhances immune system response. โ D) It promotes angiogenesis.
37. Which of the following cancers is strongly linked to the human papillomavirus (HPV)? โ A) Breast cancer โ B) Lung cancer โ C) Cervical cancer โ D) Ovarian cancer 38. In which way do cancer cells differ from normal cells in terms of contact inhibition? โ A) Cancer cells stop growing when they touch neighboring cells. โ B) Cancer cells continue to divide even when they come into contact with neighboring cells. โ C) Cancer cells have fewer gap junctions, promoting slower growth. โ D) Cancer cells rely on contact inhibition for proper growth. 39. What is the role of G-proteins in cell signaling? โ A) They directly bind ligands to produce a cellular response. โ B) They link receptors to effector proteins and mediate intracellular signaling. โ C) They act as enzymes that break down second messengers. โ D) They transport ions across the cell membrane. 40. Which of the following second messengers is involved in the G-protein signaling pathway? โ A) Calcium โ B) Glucose โ C) Chloride โ D) ATP 41. What is the function of tumor-suppressor genes in normal cells? โ A) Promote uncontrolled cell division โ B) Inhibit cell division when DNA is damaged โ C) Promote angiogenesis
47. What is the mechanism behind pharmacodynamic drug tolerance? โ A) Lower concentrations of the drug reaching the receptor โ B) Increased receptor turnover or downregulation โ C) Drug breakdown in the liver โ D) Faster metabolic rate 48. What cellular process is most often disrupted in cancer cells? โ A) Protein synthesis โ B) Normal cell division โ C) DNA transcription โ D) Energy production 49. What is the role of anti-angiogenesis factors in resisting cancer growth? โ A) They stop cancer cells from forming new blood vessels. โ B) They promote cancer cell division. โ C) They inhibit tumor-suppressor genes. โ D) They block immune cell function. 50. In secondary active transport, which of the following is true? โ A) Energy is directly supplied by ATP hydrolysis. โ B) One molecule moves down its electrochemical gradient to drive the movement of another against its gradient. โ C) Only one molecule is transported at a time. โ D) It only occurs in the presence of ion channels.
Answer Key:
1. B
2. C
3. C
4. C
5. B
6. A
7. C
8. B
9. C
10. B
11. B
12. B
13. B
14. B
15. B
16. A
17. C
18. A
19. A
20. B
21. A
22. C
23. C
24. C
25. C
26. B
27. C
28. B
29. A
30. B
31. A
32. C
33. B
34. C
35. B
36. B
37. C
38. B
39. B
40. A
41. B
42. C
