File: Chap03, Chapter 3: Structure and Function of the Cell



Bio1110 Practice Test 1 (chps.1-3)

1. Which of the following activities would represent a physiological study?

A. observing the structure of the interior of the heart

B. determining the normal blood sugar levels for 20 year old students

C. examining the surface of a bone

D. viewing muscle tissue through a microscope

2. Consider the following structural levels: organ, tissue, and organ system. Which

level encompasses the other two?

A. tissue

B. organ system

C. organ

3. In a negative feedback mechanism, the response of the effector:

A. reverses the original stimulus.

B. enhances the original stimulus.

C. has no effect on the original stimulus.

D. initiates the response.

4. The smallest living units in the body are:

A. elements.

B. sub-atomic particles.

C. cells.

D. molecules.

5. The structural and functional unit of all living organisms is the

A) ribosome.

B) cell.

C) organ.

D) organelle.

E) plasma membrane.

6. The plasma membrane

A) separates the nucleus from the rest of the cell.

B) is a rigid protein membrane.

C) is not permeable.

D) has a single layer of phospholipids.

E) regulates movement of materials into and out of the cell.

7. The environment outside the plasma membrane is most appropriately referred to as

A) intracellular.

B) extracellular.

C) multicellular.

D) centrocellular.

E) none of the above.

8. The fluid-mosaic model of the plasma membrane suggests that

A) cholesterol forms the outermost layer of the membrane.

B) proteins form a "liquid" sea in the membrane.

C) phospholipids form a single lipid layer in the center of the membrane.

D) the membrane is neither rigid nor static in structure.

E) proteins are not a part of the membrane.

9. Which of the following is correctly matched with its function?

A) channel proteins - are part of an intercellular communication system

B) marker molecules - are primarily steroids

C) receptor molecules - attach to ligand molecules.

D) peripheral proteins - penetrate the lipid bilayer from one surface to the other.

E) nongated ion channels - are always closed.

10. ATP

A) is a nucleotide found in DNA.

B) stores genetic information.

C) is a sugar found in transfer RNA.

D) serves as the energy currency of the cell.

E) can store, but cannot release energy in the cell.

11. When a sperm cell comes into contact with an egg cell, there is a change in the electrical charge across the plasma membrane and various channel proteins close. These channels would be called

A) open-gated channels.

B) voltage-gated channels.

C) chemical-gated channels.

D) ligand-gated channels.

E) nongated ion channels.

12. Channel proteins

A) are binding sites for other molecules.

B) utilize the G protein complex to function.

C) are found only on endoplasmic reticulum.

D) allow cells to recognize one another.

E) provide a "door" through which extracellular molecules can enter the cell

13. The plasma membrane is selectively permeable. This means

A) only gases and water can pass through it.

B) substances need permission to pass through it.

C) only certain substances can pass through it.

D) substances need carrier molecules to pass through it.

E) ATP is always needed to move molecules across the plasma membrane.

14. Which of the following statements concerning membrane transport across the plasma membrane is true?

A) Polar molecules are transported more easily than nonpolar molecules.

B) Lipid-soluble substances pass through the membrane by dissolving in the lipid bilayer.

C) Water cannot move through the membrane.

D) Generally, cations pass through the membrane more easily than anions.

E) All molecules are moved across by active transport.

15. The aroma of cookies baking in the kitchen reaches you in the living room. The distribution of this odor throughout the house is an example of

A) active transport.

B) dialysis.

C) osmosis.

D) filtration.

E) simple diffusion.

16. In the process of diffusion, net movement of substances is always from a region

A) outside the cell to a region inside the cell.

B) inside the cell to a region outside the cell.

C) of lower concentration to a region of higher concentration.

D) of higher concentration to a region of lower concentration.

E) none of the above

17. Osmosis is the diffusion of _____ across a selectively permeable membrane.

A) urea

B) oxygen

C) water

D) sodium

E) sugar

Use the following diagram for questions 18-19.

[pic]

18. Phospholipids are important components of the plasma membrane. What does “A” represent on the diagram?

A) phosphorus

B) oxygen

C) nitrogen

D) polar (hydrophilic) region

E) nonpolar (hydrophobic) region

19. Phospholipids are important components of the plasma membrane. What does “B” represent on the diagram?

A) phosphorus

B) oxygen

C) nitrogen

D) polar (hydrophilic) region

E) nonpolar (hydrophobic) region

20. Which of the following will increase the rate of diffusion?

A) an increase in the viscosity of the solvent

B) an increase in the temperature

C) an increase in the molecular weight of the diffusing particles

D) an increase in the distance the molecules have to travel

E) all of the above

21. DNA

A) must travel to ribosomes to function.

B) contains the sugar deoxyribose.

C) is a single-stranded molecule.

D) is one of several amino acids.

E) does not resemble a twisted ladder.

22. Which of the following nitrogen bases is found in RNA but not DNA?

A) adenine

B) guanine

C) thymine

D) uracil

E) cytosine

23. The pH value

A) increases with acidity.

B) is measured on a scale from 0 to 10.

C) is determined by the concentration of hydrogen ions.

D) reflects the sodium content of body fluids.

E) decreases with alkalinity.

24. Which of the following statements best describes RNA?

A) RNA is found outside a cell.

B) RNA contains the base thymine.

C) RNA is a single-stranded molecule.

D) RNA molecules associate with histones to form chromatin.

E) RNA is a double helix.

25. Solution A contains 5 grams of sugar per liter while solution B contains 2 grams of sugar per liter. The solutions are separated by a selectively permeable membrane. If the solvent in both solutions is water, predict in which direction most of the water molecules will move.

A) move by simple diffusion from solution A to solution B

B) move by osmosis from solution B to solution A

C) move by active transport from solution B to solution A

D) move by filtration from solution A to solution B

E) there will be no movement of water

26. If 0.9% saline solution is isotonic to a cell, then a 0.5% saline solution

A) is hypertonic to the cell.

B) will cause crenation of the cell.

C) is hypotonic to the cell.

D) will shrink the cell.

E) will not affect the cell.

27. Which of the following would be classified as a lipid?

A) cholesterol--a steroid

B) alanine--an amino acid

C) starch--a polysaccharide

D) catalase--an enzyme

E) sucrose—-a disaccharide

28. A runner produced hypotonic sweat while running a marathon in hot weather. After the race he drank large volumes of water, as a result of the water intake his body cells will

A) shrink.

B) swell.

C) crenate.

D) shrivel.

E) not change.

29. The movement of a solution across a plasma membrane because of a pressure gradient is called

A) diffusion.

B) osmosis.

C) facilitated diffusion.

D) active transport.

E) filtration.

30. A particular membrane transport process exhibits saturation, uses carrier molecules, but does not require ATP. The process is probably

A) active transport.

B) facilitated diffusion.

C) osmosis.

D) pinocytosis.

E) phagocytosis.

31. Active transport

A) follows osmotic pressure gradients.

B) can move substances along their concentration gradient.

C) does not requires metabolic energy (ATP).

D) involves vesicle formation.

E) requires ATP.

32. The sodium-potassium exchange pump located in the plasma membrane

A) actively transports potassium into cells.

B) osmotically moves sodium into cells.

C) actively transports water out of cells.

D) moves chlorine out of cells.

E) actively transports sodium into cells.

33. Which of the following is a component of a nucleotide?

A) adenine--a nitrogen base

B) glucose--a monosaccharide

C) cholesterol--a steroid

D) calcium ions

E) ATP

34. ATP

A) can be synthesized from ADP.

B) stores and releases energy in the cell.

C) is associated with a reversible reaction.

D) is associated with anabolism and catabolism.

E) all of the above.

35. Cytoplasm is found

A) in the nucleus.

B) outside the nucleus but inside the plasma membrane.

C) in the cisternae of the endoplasmic reticulum.

D) on the cristae of the mitochondria.

E) between the phospholipids in the plasma membrane.

36. Solution A increases its acidity. This means that

A) the solution is closer to neutrality.

B) the pH of the solution has increased.

C) the solution will now accept more protons.

D) the number of hydrogen ions has decreased.

E) the number of hydrogen ions has increased.

37. Organelles

A) are extracellular structures.

B) are unspecialized portions of a cell.

C) generally lack membranes.

D) vary in number and type depending on cell function.

E) are structural, but not functional parts of the cell.

38. The "control center" of the cell is the

A) nucleus.

B) ribosome.

C) mitochondrion.

D) plasma membrane.

E) endoplasmic reticulum.

Refer to the following diagram for questions 39-42.

[pic]

39. What structure does “A” represent on the diagram of the plasma membrane?

A) membrane channel protein

B) phospholipid bilayer

C) internal membrane surface

D) peripheral protein

E) receptor protein

40. What structure does “B” represent on the diagram of the plasma membrane?

A) membrane channel protein

B) phospholipid bilayer

C) internal membrane surface

D) peripheral protein

E) receptor protein

41. What structure does “C” represent on the diagram of the plasma membrane?

A) membrane channel protein

B) phospholipid bilayer

C) internal membrane surface

D) peripheral protein

E) receptor protein

42. What structure does “D” represent on the diagram of the plasma membrane?

A) membrane channel protein

B) phospholipid bilayer

C) internal membrane surface

D) peripheral protein

E) receptor protein

Refer to the following diagram for questions 43-45.

[pic]

43. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is solution “A” relative to the RBC?

A) hypotonic solution

B) hypertonic solution

C) isotonic solution

E) crenated

44. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is solution “B” relative to the RBC?

A) hypotonic solution

B) hypertonic solution

C) isotonic solution

D) hemolyzed

E) crenated

45. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is solution “C” relative to the RBC?

A) hypotonic solution

B) hypertonic solution

C) isotonic solution

D) hemolyzed

E) crenated

Answer Key

1. B

2. B

3. A

4. D

5. B

6. E

7. B

8. D

9. C

10. D

11. B

12. E

13. C

14. B

15. E

16. C

17. C

18. D

19. E

20. B

21. B

22. D

23. C

24. C

25. B

26. C

27. A

28. B

29. E

30. B

31. E

32. A

33. A

34. E

35. B

36. E

37. D

38. A

39. B

40. A

41. E

42. D

43. C

44. B

45. A

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