Sherwood Ch 1-4
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Largest of the cytoskeletal elements
10. ANS: A PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Found only on the outer surface of the membrane
10. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Primary component of a bone
10. ANS: D PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Provides receptor sites for binding molecules in the ECF that modify cell function
11. ANS: A PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Includes cells that form glands
11. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Present in parts of the cell subject to mechanical stress
11. ANS: C PTS: 1 DIF: Knowledge
Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code. a. specificity b. saturation c. competition Carrier can handle substance X but not substance Y.
12. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Smallest element visible with a conventional electron microscope
12. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Lines the digestive tract
12. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Primary component of the brain
13. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Consist of actin
13. ANS: B PTS: 1 DIF: Knowledge
Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code. a. specificity b. saturation c. competition In the presence of substance Z there is a decreased rate of entry of substance X.
13. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Form the mitotic spindle
14. ANS: A PTS: 1 DIF: Knowledge
Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code. a. specificity b. saturation c. competition The concentration of substance X outside the cell continues to increase but the rate of substance X's transport into the cell remains constant.
14. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Includes blood as a major type
14. ANS: D PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Essential for creating and maintaining an asymmetrical cell shape
15. ANS: A PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Cation in greatest concentration in the ICF
15. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Has relatively few cells within an extracellular material
15. ANS: D PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Cation in greatest concentration in the ECF
16. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Composed of tubulin
16. ANS: A PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Has one specific type classified as "smooth"
16. ANS: C PTS: 1 DIF: Knowledge
Temperature-sensitive nerve cells monitor the body temperature and provide information about its status to a temperature-control center in the hypothalamus, a part of the brain. The hypothalamus can bring about adjustments in body temperature by inducing shivering or sweating, among other things. Indicate the roles served by each component of this control system using the following answer code. a. controlled variable b. integrator c. sensor d. effector Body temperature
17. ANS: A PTS: 1 DIF: Comprehension
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Provide a pathway for axonal transport
17. ANS: A PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Anion in greatest concentration in the ICF
17. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Play a key role in muscle contraction
18. ANS: B PTS: 1 DIF: Knowledge
Temperature-sensitive nerve cells monitor the body temperature and provide information about its status to a temperature-control center in the hypothalamus, a part of the brain. The hypothalamus can bring about adjustments in body temperature by inducing shivering or sweating, among other things. Indicate the roles served by each component of this control system using the following answer code. a. controlled variable b. integrator c. sensor d. effector Temperature-sensitive nerve cells
18. ANS: C PTS: 1 DIF: Comprehension
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Anion in greatest concentration in the ECF
18. ANS: D PTS: 1 DIF: Knowledge
Match the term to its description. a. microtubules b. microfilaments c. intermediate filaments Slide past each other to cause ciliary bending
19. ANS: A PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion whose equilibrium potential is greater than the resting membrane potential
19. ANS: B PTS: 1 DIF: Knowledge
Temperature-sensitive nerve cells monitor the body temperature and provide information about its status to a temperature-control center in the hypothalamus, a part of the brain. The hypothalamus can bring about adjustments in body temperature by inducing shivering or sweating, among other things. Indicate the roles served by each component of this control system using the following answer code. a. controlled variable b. integrator c. sensor d. effector Skeletal muscles and sweat glands
19. ANS: D PTS: 1 DIF: Comprehension
Indicate whether the following physiological event represents: a. feedforward control b. negative feedback control c. positive feedback control A small fire initiated with a match becomes a raging forest fire.
2. ANS: C PTS: 1 DIF: Application
Match the term to the correct description. a. collagen b. elastin c. fibronectin d. keratin Intracellular protein that supports desmosomes
2. ANS: D PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Responsible for cell shape and movement
2. ANS: F PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion whose equilibrium potential is opposite in charge of the resting membrane potential
20. ANS: A PTS: 1 DIF: Knowledge
Temperature-sensitive nerve cells monitor the body temperature and provide information about its status to a temperature-control center in the hypothalamus, a part of the brain. The hypothalamus can bring about adjustments in body temperature by inducing shivering or sweating, among other things. Indicate the roles served by each component of this control system using the following answer code. a. controlled variable b. integrator c. sensor d. effector Hypothalamus
20. ANS: B PTS: 1 DIF: Comprehension
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Contains enzymes important in detoxifying various wastes
20. ANS: D PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion whose equilibrium potential is exactly equal to the resting membrane potential
21. ANS: D PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator House safety
21. ANS: E PTS: 1 DIF: Evaluation
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Important component of cilia and flagella
21. ANS: H PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Continuous extensive organelle consisting of a network of tubules and flattened filament
22. ANS: A PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator 911 call
22. ANS: B PTS: 1 DIF: Evaluation
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Cation to which the membrane is most permeable under resting conditions
22. ANS: B PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator Police officers
23. ANS: A PTS: 1 DIF: Evaluation
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Anion to which the membrane is impermeable
23. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Removes unwanted cellular debris and foreign material
23. ANS: C PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion that has the predominant influence on the resting membrane potential
24. ANS: B PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator Person calling 911
24. ANS: C PTS: 1 DIF: Evaluation
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Produces most of the ATP for most cells
24. ANS: E PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion that is actively transported out of the cell
25. ANS: A PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator Dispatcher
25. ANS: F PTS: 1 DIF: Evaluation
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Acts as a mechanical stiffener
25. ANS: I PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion that is actively transported into the cell
26. ANS: B PTS: 1 DIF: Knowledge
Someone sees a burglar breaking into your house, so they call 911 and the dispatcher sends police officers to your house. Relating this scenario to a feedback loop that maintains homeostasis in your body, indicate the role of each component using the following answer code. a. Effector b. Message sent from sensor c. Sensor d. Message sent from integrator e. Controlled variable f. Integrator Radio call to police officers
26. ANS: D PTS: 1 DIF: Evaluation
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Synthesizes proteins for use in the cytosol
26. ANS: G PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Consists of stacks of flattened sacs
27. ANS: B PTS: 1 DIF: Knowledge
Indicate the various roles of the following ions using the answer in the column below. a. Na+ b. K+ c. A- d. Cl- Ion whose concentration gradient is established by the membrane potential
27. ANS: D PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Concentration gradient for K+ at resting potential
28. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament May function as transporter of materials through the nuclear membrane
28. ANS: F PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Electrical gradient for K+ at resting potential
29. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Used as "highway" for kinesin and dynein
29. ANS: H PTS: 1 DIF: Knowledge
Indicate whether the following physiological event represents: a. feedforward control b. negative feedback control c. positive feedback control Increased cardiac activity to elevate blood pressure when blood pressure is low
3. ANS: B PTS: 1 DIF: Application
Match the term to the correct description. a. collagen b. elastin c. fibronectin d. keratin Extracellular protein promoting cell adhesion
3. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Highly organized membrane-bound intracellular structures
3. ANS: E PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Electrical gradient for K+ at EK+
30. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Used as "highway" for myosin
30. ANS: I PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Concentration gradient for Na+ at resting potential
31. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. ER b. Golgi complex c. lysosome d. peroxisome e. mitochondrion f. vault g. free ribosome h. microtubule i. microfilament Descendents of bacteria that were engulfed by primitive cells
31. ANS: E PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Electrical gradient for Na+ at resting potential
32. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Hair-like motile protrusions
32. ANS: B PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Electrical gradient for Na+ at ENa+
33. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Increase the surface area of the small intestine epithelium
33. ANS: C PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Na+-K+ pump for Na+
34. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Sweep mucus and debris out of respiratory airways
34. ANS: B PTS: 1 DIF: Knowledge
Indicate whether the force in question tends to move the involved ion into or out of the cell by filling in the blank using the following code. a. tends to move the ion into the cell b. tends to move out of the cell Na+-K+ pump for K+
35. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Increase the surface area of the kidney tubules
35. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Enable sperm to move
36. ANS: A PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. concentration of K+ in the ECF B. concentration of K+ in the ICF
36. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Whip-like appendages
37. ANS: A PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. concentration of Na+ in the ECF B. concentration of Na+ in the ICF
37. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. flagella b. cilia c. microvilli Guide egg to oviduct
38. ANS: B PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. concentration of A- in the ECF B. concentration of A- in the ICF
38. ANS: B PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. permeability of a cell membrane to K+ B. permeability of a cell membrane to A-
39. ANS: A PTS: 1 DIF: Knowledge
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Disassembles and reassembles within pseudopods
39. ANS: D PTS: 1 DIF: Knowledge
Indicate whether the following physiological event represents: a. feedforward control b. negative feedback control c. positive feedback control Doing warm-up exercises prior to a sporting event in order to prepare one's muscles for the event.
4. ANS: A PTS: 1 DIF: Application
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Selectively controls movement of molecules between the intracellular fluid and the extracellular fluid
4. ANS: A PTS: 1 DIF: Knowledge
Match the term to the correct description. a. collagen b. elastin c. fibronectin d. keratin Enables tissues to stretch and recoil
4. ANS: B PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. permeability of a cell membrane to K+ B. permeability of a cell membrane to Na+
40. ANS: A PTS: 1 DIF: Knowledge
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Moves along the smallest component of the cytoskeleton
40. ANS: G PTS: 1 DIF: Comprehension
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Separates chromosomes during mitosis
41. ANS: B PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. concentration gradient for K+ at EK+ B. electrical gradient for K+ at EK+
41. ANS: C PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. resting potential in a nerve cell B. equilibrium potential for K+
42. ANS: B PTS: 1 DIF: Knowledge
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Forms a covering around an endosome
42. ANS: E PTS: 1 DIF: Knowledge
The following questions refer to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation using the following answer code. a. A is greater than B b. B is greater than A c. A and B are equal A. amount of Na+ transported out of the cell B. amount of K+ transported into the cell
43. ANS: A PTS: 1 DIF: Knowledge
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Moves away from the minus end of the cytoskeleton's largest components
43. ANS: C PTS: 1 DIF: Comprehension
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Causes pinching off of endocytic vesicles
44. ANS: A PTS: 1 DIF: Knowledge
Match the cellular protein with its correct characteristic. a. dynamin b. tubulin c. kinesin d. actin e. clathrin f. dynein g. myosin Moves toward the centriole along tubulin protein
45. ANS: F PTS: 1 DIF: Comprehension
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Serves as carriers to transport particles across the membrane
5. ANS: A PTS: 1 DIF: Knowledge
Indicate whether the following physiological event represents: a. feedforward control b. negative feedback control c. positive feedback control A decrease in body temperature causes a decrease in metabolism, which causes less heat to be generated, which causes the body temperature to decrease even more.
5. ANS: C PTS: 1 DIF: Application
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Consists of organelles and cytosol
5. ANS: C PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Determines the degree of fluidity of the membrane
6. ANS: C PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Composed of cells specialized for contraction
6. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Site of intermediary metabolism
6. ANS: D PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Important in cell aggregation to form tissues
7. ANS: B PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Includes cells specialized for exchanging material between plasma and interstitial fluid
7. ANS: B PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Permits incompatible chemical reactions to occur simultaneously in the cell
7. ANS: E PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Forms channels through the membrane
8. ANS: A PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Separates contents of the cell from its surroundings
8. ANS: A PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Connects, supports, and anchors body parts
8. ANS: D PTS: 1 DIF: Knowledge
Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. a. protein b. carbohydrate c. lipid bilayer Serves as membrane-bound enzymes
9. ANS: A PTS: 1 DIF: Knowledge
Use the following answer code to indicate which tissue is being identified. a. nervous tissue b. epithelial tissue c. muscle tissue d. connective tissue Primary component of the heart
9. ANS: C PTS: 1 DIF: Knowledge
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Site of fat and glycogen storage
9. ANS: D PTS: 1 DIF: Knowledge
The pancreas is part of the endocrine system and secretes the hormone insulin, which allows most body cells to absorb glucose from the blood. A lack of insulin can result in hyperglycemia (high blood glucose), which can adversely affect one's health. Describe the roles of the digestive system, circulatory system, and endocrine systems in maintaining glucose homeostasis when a person eats a sugary meal.
ANS: The digestive system breaks down the sugary meal and transports the sugars into the blood. The circulatory system transports the sugars throughout the body. If the level of glucose in the blood increases above optimum, the endocrine system releases insulin that causes body cells to absorb glucose, thus lowering the glucose to optimum levels in the blood. PTS: 1 DIF: Comprehension
Explain the long-term adaptations made by the heart in response to an exercise regimen of sufficient intensity and duration, and explain how this is beneficial to the heart and to the athlete.
ANS: The heart increases its strength and efficiency so that it pumps more blood per beat. This allows the muscles to receive more oxygen to meet the increased demand. Because of the increased pumping ability, the heart does not have to beat as rapidly to pump a given quantity of blood as it did before beginning the exercise regimen. PTS: 1 DIF: Comprehension
Indicate which of the characteristics applies to 1) glycolysis, 2) citric-acid cycle, or 3) oxidative phosphorylation. a. directly uses inspired oxygen b. does not directly use inspired oxygen c. takes place in the cytosol d. takes place in the mitochondrial matrix e. takes place on the inner mitochondrial membrane f. yields fewer than 5 ATP molecules for each glucose molecule g. yields more than 5 ATP molecules for each glucose molecule
ANS: glycolysis: b, c, f; citric-acid cycle: b, d, f; oxidative phosphorylation: a, e, g PTS: 1 DIF: Knowledge
The resting membrane potential of a typical nerve cell is about ____________________ millivolts.
ANS: -70 PTS: 1 DIF: Knowledge
A solution containing ____________________ mOsm of solute is isotonic to human cells.
ANS: 300 PTS: 1 DIF: Knowledge
Myelinated fibers conduct impulses about ____________________ times faster than unmyelinated fibers of the same diameter.
ANS: 50 PTS: 1 DIF: Knowledge
Two ATP molecules could provide energy for a sodium-potassium pump to move ____ ions out of the cell for every ____ ions it moves into the cell. a. 6 Na+; 3 K+ b. 2 Na+; 3 K+ c. 3 K+; 6 Na+ d. 3 K+; 2 Na+ e. 12 Na+; 6 K+
ANS: A PTS: 1 DIF: Analysis
Which one of the following requires the cell to expend energy? a. ECF moving into a cell via pinocytosis b. Glucose moving through a facilitated diffusion carrier c. K+ ions moving out of a cell d. Water moving through an aquaporin e. Na+ ions moving through a leak channel
ANS: A PTS: 1 DIF: Analysis
Which of the following is a feedforward phenomenon? a. Increasing the amount of insulin secreted before nutrients in food enter the blood. b. Shivering in response to having cold air around the body. c. Sweating after being in a sauna for 10 minutes. d. Eating a doughnut because you are hungry. e. Jerking your hand away from a hot stove after you touch it.
ANS: A PTS: 1 DIF: Application
A change in a membrane potential from -70 mV to -60mV is an example of a. depolarization b. hyperpolarization c. polarization d. repolarization e. zero potential
ANS: A PTS: 1 DIF: Comprehension
Evaporation of sweat cooling the body is an example of a. negative feedback b. positive feedback c. a feedforward mechanism d. an intrinsic (local) control mechanism e. autoregulation
ANS: A PTS: 1 DIF: Comprehension
If neuron Y's neurotransmitter is causing neuron X's membrane potential to decrease, then we would logically conclude that this neurotransmitter causes a. increased PNa+ and PK+ b. increased PK+ or PCl- c. increased permeability to protein anions d. increased permeability to calcium ions e. None of the above
ANS: A PTS: 1 DIF: Comprehension
If neurotransmitter from Y causes the membrane potential of the postsynaptic cell to decrease slightly, then a. the synapse is excitatory b. the postsynaptic membrane's potential will be farther away from threshold c. the postsynaptic membrane causes an EPSP on the presynaptic membrane d. neurotransmitter from Y causes an IPSP on the presynaptic membrane e. both a and c are correct
ANS: A PTS: 1 DIF: Comprehension
Select the correct statement about diffusion through a membrane. a. It depends on random motion. b. It involves active forces. c. Its rate increases as the membrane's surface area decreases. d. Ions move from a lower concentration to a higher concentration. e. Large molecules diffuse faster than small molecules.
ANS: A PTS: 1 DIF: Comprehension
What might happen if you took in less than optimum amounts of niacin in your diet? a. Fewer pyruvate molecules would be produced. b. Available FAD would increase. c. The number of hydrogen ions pumped through the ETS in a given amount of time would increase. d. The number of Krebs cycles occurring in a given amount of time would increase. e. Any of the above might happen.
ANS: A PTS: 1 DIF: Comprehension
Which intercellular connections force transcellular transport to occur. a. Tight junctions b. Desmosomes c. Gap junctions d. Both A and B e. Both B and C
ANS: A PTS: 1 DIF: Comprehension
Which of the following are involved directly in myosin synthesis? a. RNA b. actin c. DNA d. microfilaments e. All of the above
ANS: A PTS: 1 DIF: Comprehension
Which of the following is least related to a description of contiguous conduction on a neuron? a. dendrite b. action potential c. refractory period d. unmyelinated axon e. nondecremental propagation
ANS: A PTS: 1 DIF: Comprehension
Which of the following is least related to glucose uptake by different cells in the body? a. receptor-mediated endocytosis b. facilitated diffusion c. carrier-mediated transport d. secondary active transport e. cotransport
ANS: A PTS: 1 DIF: Comprehension
Which of the following is not a principle of the cell theory? a. Most cells come from preexisting cells. b. Cells are the smallest things that can be alive. c. A cell's structure determines the cell's ability to function. d. All cells have certain fundamental structures and functions in common. e. Cells are the fundamental living building blocks of multicellular organisms.
ANS: A PTS: 1 DIF: Comprehension
Which pairing is most out of place? a. Mitochondrion and vesicle formation b. Lysosome and autophagia c. Cytoskeleton and vesicle transport d. ER and lipid synthesis e. Golgi body and glycoprotein processing
ANS: A PTS: 1 DIF: Comprehension
Which statement is correct? a. In presynaptic inhibition, another neuron inhibits an excitatory presynaptic input. b. An IPSP depresses information fed into the cell from an inhibitory presynaptic input. c. Not all axon terminals of an inhibitory neuron release inhibitory neurotransmitter. d. During presynaptic inhibition, there is no change in presynaptic membrane potential. e. An IPSP decreases the potential of the postsynaptic neuron.
ANS: A PTS: 1 DIF: Comprehension
Which statement(s) is/are true about membrane potentials? a. They are differences in electrical charge on opposite sides of a membrane b. They are measured in millivolts, with the sign designating the charge on the outside c. They exist because the ECF as a whole is positively-charged and the cytosol as a whole is negatively charged d. They are always positive during the resting state e. All of the above statements are true.
ANS: A PTS: 1 DIF: Comprehension
Carrier-mediated transport a. involves a specific membrane protein b. always moves substances against a concentration gradient c. always requires energy expenditure d. involves protein channels e. all of these
ANS: A PTS: 1 DIF: Knowledge
During axonal transport a. Kinesins carry axonal debris toward the axon terminal. b. Kinesins move toward the nucleus of the cell. c. Dyneins carry secretory vesicles toward the axon terminal. d. Dyneins move away from the nucleus. e. Microfilaments serve as the major intracellular "highway."
ANS: A PTS: 1 DIF: Knowledge
Graded potentials a. are local changes in membrane potential that occur in varying degrees of magnitude b. are weak action potentials c. serve as long-distance signals d. are only depolarizations e. always lead to action potentials
ANS: A PTS: 1 DIF: Knowledge
Identify the item that is not taken into a cell via receptor-mediated endocytosis. a. amino acid b. cholesterol c. vitamin B12 d. iron e. insulin
ANS: A PTS: 1 DIF: Knowledge
In convergence, a. many presynaptic cells synapse with a single postsynaptic cell b. one axon directly influences the activity of many other cells c. many dendrites converge on one cell body d. all of the above are true e. none of the above are true
ANS: A PTS: 1 DIF: Knowledge
Neuropeptides a. are sometimes co-secreted along with classical neurotransmitters b. are synthesized in the cytosol of the axon terminal c. act at the subsynaptic membrane of the postsynaptic neuron d. act slowly to bring about an IPSP or EPSP e. are larger molecules than classical neurotransmitters
ANS: A PTS: 1 DIF: Knowledge
Nutrients and oxygen are distributed through the body mainly by the ____ system. a. circulatory b. digestive c. endocrine d. integumentary e. skeletal
ANS: A PTS: 1 DIF: Knowledge
Permeability of which ion is affected by a positive feedback mechanism once threshold is reached? a. sodium b. potassium c. calcium d. chloride e. protein
ANS: A PTS: 1 DIF: Knowledge
Presynaptic facilitation results from a. alteration of calcium permeability b. continued generation of EPSPs c. neuromodulator effects d. increased neurotransmitter production e. none of the above
ANS: A PTS: 1 DIF: Knowledge
Select the incorrect characteristic of mitochondria. a. They have an inner fluid-filled space called the cristae. b. They possess their own DNA. c. They are the site of cellular respiration. d. Their inner membranes contain electron carriers. e. They possess two membranes.
ANS: A PTS: 1 DIF: Knowledge
Select the incorrect statement about the smooth ER. a. It is abundant in most cell types. b. It is found in liver cells. c. It specializes in lipid metabolism. d. In one type of cell, it is called sarcoplasmic reticulum. e. It does not contain ribosomes.
ANS: A PTS: 1 DIF: Knowledge
Select the item that is not a part of the cytoskeleton. a. inclusions b. intermediate filaments c. microfilaments d. microtubular lattice e. microtubules
ANS: A PTS: 1 DIF: Knowledge
Temporal summation on a postsynaptic neuron would occur when a. a single presynaptic input causes two EPSPs to develop in rapid succession b. an EPSP and an IPSP occur simultaneously and cancel each other out c. two EPSPs develop simultaneously from different presynaptic inputs d. two action potentials from two presynaptic inputs causes two action potentials to develop e. none of the above take place
ANS: A PTS: 1 DIF: Knowledge
The plasma membrane a. appears under an electron microscope as a double dark line with a light space between b. is composed primarily of a double layer of protein molecules with cholesterol molecules interspersed between them c. has a hydrophilic region between two hydrophobic regions d. has all of the above characteristics e. does not exhibit any of the above characteristics
ANS: A PTS: 1 DIF: Knowledge
The rough endoplasmic reticulum a. is in direct contact with certain nonmembranous organelles b. synthesizes lipids for secretion c. is called the sarcoplasmic reticulum in muscle cells d. transports proteins to its bound ribosomes e. exhibits all of the above characteristics
ANS: A PTS: 1 DIF: Knowledge
The trigger zone of a neuron a. is located at the axon hillock b. is located in the axon terminal c. contains only chemically gated channels d. conducts graded potentials to the axon e. causes action potentials to move toward the cell body and dendrites
ANS: A PTS: 1 DIF: Knowledge
When is a plasma membrane more permeable to K+ than to Na+? a. During the resting potential b. During the rising phase of an action potential c. During the rising phase of a graded potential d. Both a and b e. Both b and c
ANS: A PTS: 1 DIF: Knowledge
Which modified form of pyruvate enters the citric acid cycle? a. acetyl CoA b. adenosine diphosphate c. citric acid d. oxaloacetic acid e. pyruvic acid
ANS: A PTS: 1 DIF: Knowledge
Which of the following allows a membrane potential to be measured directly by taking into account relative permeabilities and gradients for all permeable ions? a. Goldman-Hokgkin-Katz equation b. Nernst equation c. Fick's equation d. All of the above e. Only a and c
ANS: A PTS: 1 DIF: Knowledge
Which of the following body systems is not directed entirely toward maintaining homeostasis? a. reproductive system b. endocrine system c. nervous system d. muscular system e. integumentary system
ANS: A PTS: 1 DIF: Knowledge
Which of the following does not occur in the cytosol? a. replication of chromosomes b. enzymatic regulation of intermediary metabolism c. storage of fat and glycogen d. synthesis of proteins e. glycolysis
ANS: A PTS: 1 DIF: Knowledge
Which of the following is least related to connective tissue? a. gland b. bone c. blood d. tendon e. elastin
ANS: A PTS: 1 DIF: Knowledge
Which of the following organelles contains catalase? a. peroxisomes b. mitochondria c. lysosomes d. vaults e. a, b, and c
ANS: A PTS: 1 DIF: Knowledge
Which statement is true about the absolute refractory period? a. It ensures that action potentials move in only one direction along a nerve fiber. b. It is the period when the membrane can undergo another action potential, but only if the stimulus is strong enough. c. It is the time during an action potential when voltage-gated Na+ channels are in their "closed but capable of opening" conformation. d. places a lower limit on the frequency with which a neuron can conduct action potentials. e. All of the above statements are true.
ANS: A PTS: 1 DIF: Knowledge
Which term best describes an excitable cell when a resting membrane potential is present? a. polarized b. depolarized c. hyperpolarized d. repolarized e. nonpolarized
ANS: A PTS: 1 DIF: Knowledge
__________ refers to programmed cell death, whereas _______ refers to uncontrolled cell death.
ANS: Apoptosis, necrosis PTS: 1 DIF: Knowledge
Solution 1 has two solutes (A and B) and an osmotic pressure of 250 mOsm. Solution 2 has only one solute (C) and an osmotic pressure of 300 mOsm. If a membrane between these solutions is permeable to only water and B, then a. Solution 1 will gain water from solution 2. b. Solution 2 will gain water from solution 1. c. Some of solute C will move into solution 1. d. Solution 1 has a higher osmotic pressure. e. Solution 1 would be hypertonic to a human cell.
ANS: B PTS: 1 DIF: Analysis
Which of the following solutions has a lower osmotic pressure than a human cell's cytosol? a. 2% NaCl b. 200 mOsm of NaCl c. 0.9% NaCl d. 300 mOsm of NaCl e. 280 mOsm of glucose
ANS: B PTS: 1 DIF: Analysis
A cell in the pancreas that secretes an enzyme to hydrolyzes lipids would be expected to have a. a larger-than-normal nucleus b. an extensive rough ER c. a greater-than-normal number of free ribsomes d. an extensive smooth ER e. a and d
ANS: B PTS: 1 DIF: Application
The statement "Things are going from bad to worse" would be most closely related to a. feedforward d. homeostasis b. positive feedback e. regulatory control c. negative feedback
ANS: B PTS: 1 DIF: Application
Which of the following is not an example of negative feedback? a. A low grade on an exam causes a student to study harder for the next exam. b. A small stone rolls down a hill and starts an avalanche. c. A person goes to eat in the cafeteria when he/she gets hungry. d. You change a flat tire so you can continue on a journey in your car. e. A person's body shivers after the person falls into a cold river.
ANS: B PTS: 1 DIF: Application
An electrical gradient a. favors the movement of K+ out of the cell at resting potential b. favors the movement of Na+ into the cell at resting potential c. opposes the concentration gradient for Na+ at the equilibrium potential for Na+ d. favors the movement of Cl- out of the cell at resting potential e. prevents the active transport of K+ into the cell
ANS: B PTS: 1 DIF: Comprehension
At an excitatory synapse, an action potential in the presynaptic neuron increases a. the membrane potential of the postsynaptic cell membrane b. the permeability of the postsynaptic cell to Na+ c. the permeability of the postsynaptic cell to Cl- d. the presynaptic neuron's membrane potential e. all of the above
ANS: B PTS: 1 DIF: Comprehension
At an inhibitory synapse, the postsynaptic membrane experiences a. an increase in permeability to both Na+ and K+ b. an increase in membrane potential c. hyperpolarization d. an influx of cations e. all of the above
ANS: B PTS: 1 DIF: Comprehension
Food in your stomach is in direct contact with ______ tissue. a. connective b. epithelial c. glandular d. muscle e. nervous
ANS: B PTS: 1 DIF: Comprehension
Identify the true statement(s) about the plasma membrane. a. Its transmembrane proteins are also peripheral proteins. b. Its glycocalyx functions in cell recognition. c. Its carriers contain cholesterol. d. Its channels allow passage of substances between 0.8 nm and 1 nm in diameter. e. Its transmembrane proteins are also peripheral proteins, and its channels allow passage of substances between 0.8 nm and 1 nm in diameter.
ANS: B PTS: 1 DIF: Comprehension
If neuron X causes hyperpolarization, then what does it cause in a postsynaptic neuron? a. Increased PNa+ and PK+ b. Increased PK+ or PCl- c. Increased influx of protein anions d. Increased permeability to calcium ions e. Either b or c
ANS: B PTS: 1 DIF: Comprehension
If neurotransmitter from X causes a slight hyperpolarization of a postsynaptic cell, then a. the synapse is excitatory b. the synapse is inhibitory c. the postsynaptic cell's membrane potential is becoming less negative d. the postsynaptic cell's membrane potential is becoming more positive e. b, c, and d are occurring
ANS: B PTS: 1 DIF: Comprehension
Opening a sodium channel when the membrane potential is at equilibrium will cause a. the membrane potential to become more negative b. the membrane potential to decrease c. the inside border of the membrane to become more negative d. the outside border of the membrane to become more positive e. all of the above reactions
ANS: B PTS: 1 DIF: Comprehension
Opening either a chemically-gated Na+ channel or a chemically-gated K+ channel during the resting potential would cause a. an impulse to be propagated b. a graded potential c. an action potential d. the membrane's potential to becomes more negative e. threshold voltage will be reached
ANS: B PTS: 1 DIF: Comprehension
The ability of the brain to maintain optimum blood pressure by speeding up or slowing down the heart is an example of a. intrinsic control d. Both a and c b. extrinsic control e. Both b and c c. positive feedback
ANS: B PTS: 1 DIF: Comprehension
The rate of diffusion for water-soluble substances through a membrane decreases as a. their concentration gradient increases b. their molecular weight increases c. the number of cholesterol molecules in the membrane increases d. the membrane's surface area increases e. the number of membrane carbohydrates increases
ANS: B PTS: 1 DIF: Comprehension
When the membrane potential is +15 mV, that portion of the membrane a. is at the normal resting potential b. has a positively-charged inside border c. is more permeable to Ca2+ than normal d. is in the after hyperpolarization phase of an action potential e. is in a hyperpolarized state
ANS: B PTS: 1 DIF: Comprehension
Which of the following does a person not maintain through homeostasis? a. Concentration of nutrients in the blood b. Concentration of oxygen around the body c. Blood pressure d. Temperature of the brain e. Posture while sitting in a chair
ANS: B PTS: 1 DIF: Comprehension
Which of the following is most closely related to transcellular transport? a. Cadherins b. Claudins c. Peripheral proteins d. Connexons e. Cadherins
ANS: B PTS: 1 DIF: Comprehension
Which of the following is not a function of membrane proteins? a. Transport of polar molecules b. Transport of H+ into the cell c. Binding sites for vesicles d. Cell recognition e. Passageway for water molecules
ANS: B PTS: 1 DIF: Comprehension
Which of the following would not require a carrier? a. Movement of potassium into the cell b. Movement of sodium into the cell c. Iodine uptake by thyroid gland cells d. Glucose uptake by body cells e. None of the above would require a carrier.
ANS: B PTS: 1 DIF: Comprehension
Which one of the following requires assisted membrane transport? a. Glucose moving into a cell b. K+ ions moving out of a cell c. Water moving toward a hypertonic solution d. Movement of ECF into a cell via pinocytosis e. Movement of Na+ through a symporter
ANS: B PTS: 1 DIF: Comprehension
Which statement about gap junctions is incorrect? a. They consist of protein. b. They are anchored to plaques on the inside surface of the plasma membrane. c. They allow materials to pass from one cell into an adjacent cell. d. They play a role in transmitting electrical activity through the heart. e. They consist of connexons.
ANS: B PTS: 1 DIF: Comprehension
Which statement is incorrect? a. Inhibitory synapses cause postsynaptic hyperpolarization. b. An inhibitory synapse may result in postsynaptic sodium channel opening. c. An inhibitory synapse may result in increased postsynaptic potassium efflux. d. An excitatory synapse causes depolarization of postsynaptic membranes. e. An excitatory synapse increases sodium permeability.
ANS: B PTS: 1 DIF: Comprehension
Why do most cells in the body require oxygen molecules? a. Glucose cannot be broken down without it. b. It pulls electrons off the electron transport chains in the last part of cellular respiration. c. The electron transport system must pump it through the inner membrane for chemiosmosis. d. ATP synthase uses it to add a phosphate ion to ADP in order to make ATP. e. It pulls electrons off the electron transport chains in the last part of cellular respiration and ATP synthase uses it to add a phosphate ion to ADP in order to make ATP.
ANS: B PTS: 1 DIF: Comprehension
With secondary active transport, the movement of a. H+ out of a cell by antiport is downhill b. amino acids into the cell by symport is uphill c. glucose into a cell by cotransport is downhill d. H+ is in the same direction as the movement of Na+ e. glucose is in the opposite direction as the movement of Na+
ANS: B PTS: 1 DIF: Comprehension
Which answer is true about NET water movement between two solutions that are separated by a semipermeable membrane. a. It will always be toward the solution with the lower osmotic pressure. b. It might be toward the solution with the lower osmotic pressure. c. It will always be toward the solution with the lower hydrostatic pressure. d. It might be toward both solutions at the same time. e. None of the above statements are true.
ANS: B PTS: 1 DIF: Evaluation
A typical human cell is about ____ micrometers in diameter. a. 1 to 2 b. 10 to 20 c. 80 to 100 d. 150 to 200 e. 200 to 300
ANS: B PTS: 1 DIF: Knowledge
Actin and myosin filaments are most abundant in ____ cells. a. epithelial b. muscle c. nerve d. red blood e. white blood
ANS: B PTS: 1 DIF: Knowledge
An IPSP is a. produced by increased permeability to Na+ and K+ b. produced by increased permeability to K+ or Cl- c. a hyperpolarization of the presynaptic cell d. a decrease in the postsynaptic membrane potential e. an decrease in the presynaptic membrane potential
ANS: B PTS: 1 DIF: Knowledge
Choose the incorrect statement about the cytoskeleton. a. It may help organize groups of enzymes. b. It is involved in replication of DNA. c. It serves as a mechanical stiffener. d. It is involved in cilia movement. e. It has components within microvilli.
ANS: B PTS: 1 DIF: Knowledge
Cristae are found in the a. lysosome b. mitochondrion c. nucleolus d. nucleus e. rough ER
ANS: B PTS: 1 DIF: Knowledge
During the peak of the action potential, the membrane becomes most permeable to a. sodium b. potassium c. calcium d. chloride e. protein
ANS: B PTS: 1 DIF: Knowledge
During the rising phase of the action potential, a. PK+ is much greater than PNa+ b. PNa+ is much greater than PK+ c. PK+ is the same as P Na+ d. Na+ efflux occurs e. b and d are true
ANS: B PTS: 1 DIF: Knowledge
Identify all examples of inclusions. a. peroxisome b. glycogen granule c. centriole d. vault e. glycogen granule and vault
ANS: B PTS: 1 DIF: Knowledge
Intermediate filaments a. comprise mitotic spindles b. are important in cell regions subject to mechanical stress c. comprise cilia and flagella d. form the basal bodies e. comprise cilia and flagella and form the basal bodies
ANS: B PTS: 1 DIF: Knowledge
Osmosis is a type of a. carrier-mediated transport b. diffusion c. exocytosis d. pinocytosis e. primary active transport
ANS: B PTS: 1 DIF: Knowledge
Spatial summation occurs on a postsynaptic neuron would occur when a. several EPSPs from a single presynaptic input sum to reach threshold b. EPSPs from several presynaptic inputs sum to reach threshold c. there is simultaneous interaction of an EPSP and an IPSP d. several IPSPs from a single presynaptic input sum to hyperpolarize the membrane e. none of the above take place
ANS: B PTS: 1 DIF: Knowledge
The falling phase of the action potential is due to a. calcium influx b. potassium efflux c. chloride influx d. sodium efflux e. the action of Na+-K+ pumps
ANS: B PTS: 1 DIF: Knowledge
The influence of oxytocin on the uterus during childbirth and the subsequent effect of uterine stretch on the release of oxytocin is an example of a. negative feedback b. positive feedback c. extrinsic control d. negative feedback and extrinsic control e. none of these
ANS: B PTS: 1 DIF: Knowledge
The nodes of Ranvier are a. action potential recordings b. breaks in the myelin covering c. spaces between neurons d. specialized cells around axons e. structures on axon terminals that release neurotransmitter
ANS: B PTS: 1 DIF: Knowledge
The smooth endoplasmic reticulum a. is most abundant in cells specialized for protein secretion b. gives rise to transport vesicles containing newly synthesized molecules wrapped in a layer of smooth ER membrane c. consists of stacks of relatively flattened sacs called cristae d. has only a few ribosomes attached to it e. is a primary site for glycolysis
ANS: B PTS: 1 DIF: Knowledge
The two major regulatory systems in the body are a. nervous and respiratory b. nervous and endocrine c. endocrine and respiratory d. endocrine and lymphatic e. circulatory and endocrine
ANS: B PTS: 1 DIF: Knowledge
Which channel type is sensitive to serotonin? a. voltage-gated b. chemically-gated c. mechanically-gated d. acoustically-gated e. none of these
ANS: B PTS: 1 DIF: Knowledge
Which extracellular fiber does not develop properly in scurvy? a. actin b. collagen c. elastin d. fibronectin e. myosin
ANS: B PTS: 1 DIF: Knowledge
Which of the following cannot pass through a plasma membrane by primary active transport? a. Sodium b. Glucose c. Calcium d. Potassium e. Hydrogen ions
ANS: B PTS: 1 DIF: Knowledge
Which of the following does not apply to lysosomes? a. They contain hydrolytic enzymes. b. They generate hydrogen peroxide. c. They aid in the breakdown of material that is taken into the cell through endocytosis. d. When they are abnormal, Tay-Sachs disease may result. e. They help remove damaged organelles.
ANS: B PTS: 1 DIF: Knowledge
Which of the following is not a function of membrane proteins? a. Some act as channels. b. They determine the fluidity of the membrane. c. Some will transport glucose. d. They include docking-marker acceptors. e. Some act as enzymes.
ANS: B PTS: 1 DIF: Knowledge
Which of the following is not a graded potential? a. end-plate potential b. action potential c. slow-wave potential d. receptor potential e. postsynaptic potential
ANS: B PTS: 1 DIF: Knowledge
Which of the following is not part of the extracellular matrix? a. complex carbohydrates b. connexons c. collagen d. elastin e. fibronectin
ANS: B PTS: 1 DIF: Knowledge
Which of the following is not true for lipophilic hormones? a. Cells do not store them. b. They are all derived from cholesterol. c. They are bound to protein in the blood. d. They typically activate genes. e. Only a small portion of the hormone is biologically active.
ANS: B PTS: 1 DIF: Knowledge
Which of the following represents a site of storage for molecules that a cell uses as a source of energy? a. peroxisome b. inclusion c. lysosome d. nucleus e. Golgi complex
ANS: B PTS: 1 DIF: Knowledge
Which sequence represents a correct hierarchy of biological organization in a human, from smaller to larger? a. chemical, organ, tissue, system, organism b. cell, tissue, organ, system, organism c. tissue, cell, system, organism, organ d. organ, tissue, cell, organism, system e. system, cell, organ, organism, tissue
ANS: B PTS: 1 DIF: Knowledge
Identify the pairing that has the least related items: a. pinocytosis, endocytosis b. catalase, peroxisome c. clathrin, secretory vesicle d. phagocytosis, pseudopods e. t-SNARE, plasma membrane
ANS: C PTS: 1 DIF: Analysis
The rate at which "X" can diffuse through a plasma membrane is inversely proportional to the a. lipid solubility of X b. concentration gradient for X c. molecular weight of X d. membrane's surface area e. lipid solubility and molecular weight of X
ANS: C PTS: 1 DIF: Analysis
Which pairing has the most closely related items? a. Tight junction, connexon b. Gap junction, cadherin c. Tight junction, kiss site d. Gap junction, plaque e. Desmosome, claudin
ANS: C PTS: 1 DIF: Analysis
A hypothetical postsynaptic neuron has three presynaptic inputsX, Y, and Z. When X and Y are stimulated simultaneously, the postsynaptic neuron undergoes an action potential, yet when X and Z are stimulated simultaneously, there is no change in the postsynaptic neuron's potential. What can you logically conclude? a. Y and Z are both excitatory. b. Y and Z are both inhibitory. c. Y is excitatory and Z is inhibitory. d. Y is inhibitory and Z is excitatory. e. Not enough information to answer.
ANS: C PTS: 1 DIF: Application
If a neuron were experimentally stimulated at both ends simultaneously, then a. the action potentials would pass in the middle and travel to the opposite ends b. the action potentials would meet in the middle and then be propagated back to their starting positions c. the action potentials would stop as they met in the middle d. the strongest action potential would override the weaker action potential e. summation would occur when the action potentials met in the middle, resulting in a two larger action potentials traveling in opposite directions
ANS: C PTS: 1 DIF: Application
Solution 1 has a higher concentration of NaCl than solution 2. A membrane permeable only to Na+ and water separates the two membranes. Which of the following is true? a. Na+ will diffuse into solution 2 until the two solutions become isotonic. b. Solution 2 has a higher osmolarity. c. A membrane potential will develop, with the negative side being in solution 1. d. Solution 2 will gain water from solution 1. e. Eventually, solution 2 will contain only Na+ and solution 1 will contain only Cl-
ANS: C PTS: 1 DIF: Application
What might account for a net movement of water from solution X into solution Y? a. Solution X has a higher osmolarity than the cell. b. Solution X has more milliosmoles of solute per liter than the cell. c. Solution X has a higher hydrostatic pressure than solution Y d. All of the above e. Only a and b
ANS: C PTS: 1 DIF: Application
Which of the following is a mechanistic explanation of a physiological phenomenon? a. You breathe to obtain oxygen. b. You sweat to cool off. c. Your stomach secretes digestive juices when stimulated by the nervous system. d. Your heart beats to pump blood. e. Your kidneys produce urine so that cellular wastes do not poison your body.
ANS: C PTS: 1 DIF: Application
Which statement is most likely to be true about a crenating cell? a. It is surrounded by a hypotonic ECF. b. It has a lower osmotic pressure than the ECF c. It has a higher concentration of solutes than the ECF. d. It is experiencing a net gain of water. e. It is surrounded by a solution having a solute concentration less than 300 mOsm/L.
ANS: C PTS: 1 DIF: Application
A Ca2+ pump in the plasma membrane a. pumps Ca+2 into the cell b. is a secondary active transport carrier c. is an ATPase d. is a symporter e. allows Ca+2 to diffuse into the cell
ANS: C PTS: 1 DIF: Comprehension
A substance does not move down a concentration gradient through a. a symporter b. an antiporter c. a primary active transporter d. a secondary active transporter e. facilitated diffusion carrier
ANS: C PTS: 1 DIF: Comprehension
Binding of an excitatory neurotransmitter to a postsynaptic neuron causes a. voltage-gated Na+ channels open b. voltage-gated K+ channels open c. chemically-gated Na+ channels open d. voltage-gated Cl- channels open e. chemically-gated Cl- channels open
ANS: C PTS: 1 DIF: Comprehension
During the resting potential a. K+ ions leave the cell along a concentration gradient and along an electrical gradient. b. K+ ions leave the cell against a concentration gradient but along an electrical gradient. c. Na+ ions enter the cell along a concentration gradient and along an electrical gradient. d. Na+ ions enter the cell along a concentration gradient but against an electrical gradient. e. Cl- ions enter the cell along a concentration gradient and along an electrical gradient.
ANS: C PTS: 1 DIF: Comprehension
Identify the incorrect statement about the plasma membrane. a. Cholesterol contributes to its stability. b. Its lipids may surround CAMs. c. Its primary components are glycoproteins and cholesterol. d. Its lipid bilayer is flexible. e. Its glycocalyx is in contact with ECF.
ANS: C PTS: 1 DIF: Comprehension
Identify the true statement(s) about anaerobic respiration. a. It completely oxidizes certain food molecules. b. It forms carbon dioxide. c. It donates hydrogens to NAD molecules. d. All of the above statements are true. e. It donates hydrogens to pyruvate molecules.
ANS: C PTS: 1 DIF: Comprehension
Identify the true statement(s) about the plasma membrane. a. Its lipid region allows most ions to diffuse between the cytosol and ECF. b. Its channels allow cholesterol to diffuse between the ECF and cytosol. c. Some of its carriers transport sodium. d. Its phospholipids are held to one another by CAMs. e. All except its phospholipids are held to one another by CAMs.
ANS: C PTS: 1 DIF: Comprehension
If osmosis is occurring, then you know there is a net movement of water to an area of a. lower osmotic pressure b. higher hydrostatic pressure c. higher solute concentration d. higher water concentration e. lower osmotic pressure and higher water concentration
ANS: C PTS: 1 DIF: Comprehension
In a plasma membrane, simple diffusion of various substances can occur a. through channels b. through carriers c. between phospholipid molecules d. through aquaporins e. into the cell but not out of the cell
ANS: C PTS: 1 DIF: Comprehension
Saltatory conduction a. occurs in unmyelinated nerve fibers b. is slower than contiguous conduction because myelin acts as an insulator to slow the impulse c. involves the impulse jumping from one node of Ranvier to the adjacent node d. refers to the action potential spreading from one Schwann cell to the adjacent Schwann cell e. occurs along dendrites and axons of certain neurons
ANS: C PTS: 1 DIF: Comprehension
Select the incorrect association. a. anatomy/heart structure b. human body/multicellularity c. oxygen/cellular waste d. physiology/stomach function e. unicellularity/amoeba
ANS: C PTS: 1 DIF: Comprehension
Selective permeability of the membrane is primarily determined by a. membrane phospholipids b. how much cholesterol is present c. the number and type of membrane proteins d. the charge of the membrane e. none of these
ANS: C PTS: 1 DIF: Comprehension
The concentration gradient for a. K+ favors its movement into the ECF b. Na+ favors its movement out of the cytosol c. K+ and Na+ are maintained by active transport d. Na+ opposes the electrical gradient for Na+ e. Cl- favors its movement out of the cytosol
ANS: C PTS: 1 DIF: Comprehension
The negative charge established along the cytosolic border a nerve cell membrane is due to a. movement of sodium ions into the cell b. movement of proteins out of the cell c. higher permeability of K+ relative to Na+ d. movement of proteins through membrane channels e. both b and d
ANS: C PTS: 1 DIF: Comprehension
The plasma membrane a. has a slight excess of positive charges along its cytosol side during the resting state b. is composed primarily of cholesterol surrounded by carbohydrates c. is more permeable to K+ than to Na+ at the resting state d. has peripheral proteins that act as carriers e. exhibits all of the characteristics listed above
ANS: C PTS: 1 DIF: Comprehension
The term aerobic refers to reactions a. that occur in the lungs b. that require carbon dioxide c. that continue only when oxygen is available d. do not require an input of carbon dioxide e. that occur without oxygen
ANS: C PTS: 1 DIF: Comprehension
What is primarily responsible for the development of a resting membrane potential? a. More diffusion and active transport of cations out of the cell than into the cell b. Pumping 2 K+ ions out of the cell for every three Na+ ions pumped into the cell c. More K+ ions diffusing into the cell than there are Na+ ions diffusing out of the cell d. More anions diffusing into the cell than are diffusing out of the cell e. None of the above are primarily responsible.
ANS: C PTS: 1 DIF: Comprehension
Which of the following can diffuse between a membrane's phospholipids into the cytosol? a. glucose b. sodium c. carbon dioxide d. integrin molecule e. a small secretory product
ANS: C PTS: 1 DIF: Comprehension
Which of the following is most closely associated with cilia? a. actin and myosin b. intermediate filaments c. dynein and microtubules d. microfilaments and actin e. myosin motor molecules and microfilaments
ANS: C PTS: 1 DIF: Comprehension
Which of the following is not contained within the cytoplasm? a. ribosomal subunits b. cytosol c. plasma membrane d. endoplasmic reticulum e. catalase
ANS: C PTS: 1 DIF: Comprehension
Which of the following statements about negative feedback is incorrect? a. It exists when a change in a regulated variable triggers a response that opposes the change. b. It exists when the input to a system increases the output and the output inhibits the input. c. The control system's input and output continue to enhance each other. d. It is the method by which most of the body's control mechanisms operate. e. It helps maintain the body's dynamic, steady state.
ANS: C PTS: 1 DIF: Comprehension
Which pairing shows the least-related items? a. Na+-K+ pump, transmembrane protein b. Facilitated diffusion carrier, integral protein c. Aquaporin, peripheral protein d. Calcium pump, integral protein e. Na+-K+ pump, integral protein
ANS: C PTS: 1 DIF: Comprehension
A threshold potential is a. the potential achieved when two opposing forces acting upon an ion (concentration and electrical gradients) achieve a state of equilibrium b. the peak potential achieved during an action potential c. the point at which there is an explosive increase in Na+ or Ca2+ permeability d. the potential at which K+ permeability increases e. always a positive potential
ANS: C PTS: 1 DIF: Knowledge
All of the following may be considered second messengers except a. inositol triphosphate b. calcium ions c. phosphodiesterase d. cyclic AMP e. diacylglycerol
ANS: C PTS: 1 DIF: Knowledge
Cystic fibrosis is caused by abnormal a. accumulation of mucus b. levels of insulin c. chloride channels in plasma membranes d. potassium channels in plasma membranes e. sodium-potassium pumps
ANS: C PTS: 1 DIF: Knowledge
Exocytosis of secretory products from neuron terminals is triggered by the entry of ____ into the ____. a. K+; cytosol b. Na+; ECF c. Ca2+; cytosol d. ATP; plasma membrane e. A-; ECF
ANS: C PTS: 1 DIF: Knowledge
Glycolysis a. produces citric acid b. transfers energy to glucose c. produces more ATP molecules than does one turn of the Krebs cycle d. traps energy in FADH2 e. does not perform any of the functions listed above
ANS: C PTS: 1 DIF: Knowledge
Individual proteins typically pass through the plasma membrane by a. primary active transport b. symport c. vesicular transport d. secondary active transport e. facilitated diffusion
ANS: C PTS: 1 DIF: Knowledge
Local current flow a. occurs only on dendrites of neurons b. causes impulses to move from the axon hillock toward the neuron's cell body c. involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold d. occurs only on axons of neurons e. does not occur on all excitable membranes
ANS: C PTS: 1 DIF: Knowledge
Pinocytosis is a form of a. active transport b. cytokinesis c. endocytosis d. exocytosis e. hemolysis
ANS: C PTS: 1 DIF: Knowledge
Select the incorrect statement about vaults. a. They may play a role in drug resistance in cancer cells. b. They are numerous and relatively large organelles. c. They are specialized transport vesicles within nuclear pores. d. They may transport ribosomal subunits out of the nucleus. e. They are not visible by ordinary staining techniques.
ANS: C PTS: 1 DIF: Knowledge
Sweat glands consist of specialized ______ cells. a. connective b. endocrine c. epithelial d. muscle e. nervous
ANS: C PTS: 1 DIF: Knowledge
Tetanus toxin a. binds with glycine receptors, thus blocking the action of this inhibitory neurotransmitter b. destroys dopamine in the region of the brain involved in controlling complex movements c. prevents the release of GABA that inhibits neurons that innervate skeletal muscle cells d. promotes presynaptic facilitation e. causes IPSPs to occur on skeletal muscle cell membranes
ANS: C PTS: 1 DIF: Knowledge
The SNARE complex provides a. allows recognition of foreign proteins after they enter a cell b. a way for a certain enzyme to bind with the correct substrate c. a means to deliver vesicles to an appropriate site d. a mechanism necessary for receptor mediated endocytosis to occur e. all of the functions listed above
ANS: C PTS: 1 DIF: Knowledge
The bending movements of cilia and flagella a. are associated with microtubules and kinesin b. involve the alternate assembly and disassembly of actin filaments c. are produced when dynein motors pull adjacent microtubule doublets past each other d. involves dynein action on microfilaments e. involves myosin action on intermediate filaments
ANS: C PTS: 1 DIF: Knowledge
The nucleus of a neuron is housed in the a. axon b. axon hillock c. cell body d. collaterals e. dendrites
ANS: C PTS: 1 DIF: Knowledge
The respiratory system a. obtains O2 from and eliminates CO2 to the internal environment b. includes the heart and lungs c. helps regulate the pH of the internal environment by removing acid-forming CO2 from the blood d. performs all of the functions listed above e. obtains O2 from and eliminates CO2 to the internal environment and helps regulate the pH of the internal environment by removing acid-forming CO2 from the blood
ANS: C PTS: 1 DIF: Knowledge
Tight junctions a. prevent passage of materials into epithelial cells b. force materials to pass between cells c. are commonly found in digestive tract linings d. comprise part of the glycocalyx e. consist of cadherin proteins
ANS: C PTS: 1 DIF: Knowledge
When chemically-gated Na+ channels open, the membrane a. hyperpolarizes b. repolarizes c. depolarizes d. becomes more negative e. is inhibited
ANS: C PTS: 1 DIF: Knowledge
Which component below is not always found in a typical human cell? a. cytosol b. DNA c. flagellum d. plasma membrane e. water
ANS: C PTS: 1 DIF: Knowledge
Which of the following may help transport ribosomal subunits out of the nucleus? a. Golgi complex b. mitotic spindle c. vault d. centriole e. secretory vesicle
ANS: C PTS: 1 DIF: Knowledge
Which of the following statements about the Na+-K+ pump is incorrect? a. Phosphorylation of the pump must occur before K+ can attach to its binding site. b. It has ATP synthase activity. c. It helps decrease Na+ and K+ concentration gradients across the plasma membrane. d. It regulates cell volume by controlling the concentration of solutes inside the cell. e. Its action is important for secondary active transport.
ANS: C PTS: 1 DIF: Knowledge
Which statement about graded potentials is false? a. They are decremental. b. They travel only short distances. c. They are self-propagating. d. They may contribute to the development of an action potential. e. They travel in both directions along the membrane.
ANS: C PTS: 1 DIF: Knowledge
Which statement about the plasma membrane is not true? a. It serves as a mechanical barrier to hold in the contents of the cell. b. It selectively controls movement of molecules between the ECF and the cytoplasm. c. It is the barrier that surrounds the blood vessels and separates the blood plasma from the interstitial fluid. d. It contains proteins that provides for various membrane functions. e. It consists mostly of lipids and proteins.
ANS: C PTS: 1 DIF: Knowledge
Which statement is incorrect? a. A local current can occur in myelinated nerve fibers b. A local current flow from an active to an adjacent inactive area decreases the potential in the inactive area to threshold c. Contiguous conduction occurs along Schwann cells on myelinated nerve fibers d. Saltatory conduction is faster than contiguous conduction e. A local current can occur in myelinated nerve fibers
ANS: C PTS: 1 DIF: Knowledge
Which statement regarding the citric acid cycle is incorrect? a. It occurs in the mitochondrial matrix. b. It forms carbon dioxide. c. It forms two ATP molecules during each turn. d. Acetyl CoA and oxaloacetate react to form citric acid. e. Each turn forms one molecule of GTP.
ANS: C PTS: 1 DIF: Knowledge
With presynaptic inhibition, a. an IPSP occurs on the postsynaptic cell b. all excitatory information being fed into the cell is prevented c. the release of excitatory neurotransmitter from a specific presynaptic excitatory input is depressed. d. at least two of the above occur. e. none of the above occur.
ANS: C PTS: 1 DIF: Knowledge
______ transports secretory vesicles along microtubules is a. Actin b. Myosin c. Kinesin d. Tubulin e. Keratin
ANS: C PTS: 1 DIF: Knowledge
Scurvy is the result of a vitamin ____________________ deficiency and results in abnormal formation of the protein called ____________________.
ANS: C, collagen PTS: 1 DIF: Knowledge
An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.
ANS: Ca++ PTS: 1 DIF: Knowledge
____________________ are the blood vessels where materials are exchanged between the blood and the interstitial fluid.
ANS: Capillaries PTS: 1 DIF: Knowledge
____________________ muscle tissue composes the heart.
ANS: Cardiac PTS: 1 DIF: Knowledge
____________________, an enzyme found in peroxisomes, decomposes potentially toxic hydrogen peroxide.
ANS: Catalase PTS: 1 DIF: Knowledge
____________________ is responsible for maintaining the fluid nature of the plasma membrane in human cells.
ANS: Cholesterol PTS: 1 DIF: Knowledge
If neuron X causes hyperpolarization of neuron Z but neuron Y causes depolarization of neuron Z, what change would you expect in neuron Z if it is stimulated by both X and Y simultaneously? a. a significant increase in membrane potential b. a significant decrease in membrane potential c. temporal summation leading to an impulse on Z d. simultaneous influx and efflux of cations or simultaneous influx of cations and efflux of anions e. an increase in the resting membrane potential
ANS: D PTS: 1 DIF: Analysis
Which of the following is least related to glycolysis? a. NADH b. ATP c. pyruvate d. CO2 e. glucose
ANS: D PTS: 1 DIF: Analysis
Which of the following is synthesized inside certain cells and is eventually secreted. a. tRNA b. clathrin c. dynamin d. steroid hormone e. ATP
ANS: D PTS: 1 DIF: Analysis
Cell X has a resting potential of -80 mV. If a ____ opens and causes the potential to change 10 mV, the resulting potential will be ____. a. Na+ channel; -90 mV b. K+ channel; -70 mV c. Ca2+ channel; -70 mV d. Cl- channel; -70 mV e. Ca+2 channel; -90 mV
ANS: D PTS: 1 DIF: Application
If a letter in the alphabet is equated to a cell, then which of the following would be most like an organ? a. two paragraphs b. a paragraph c. a word d. a sentence e. two sentences
ANS: D PTS: 1 DIF: Application
1. A change in a membrane potential from +30 mV to -70 mV is an example of a. depolarization b. hyperpolarization c. polarization d. repolarization e. zero potential
ANS: D PTS: 1 DIF: Comprehension
All of a muscle cell's lactate is synthesized a. in Krebs cycle reactions b. from acetyl CoA c. directly from glucose d. from pyruvate e. in chemiosmosis
ANS: D PTS: 1 DIF: Comprehension
Anionic intracellular proteins (A-) cannot pass through membrane carriers because A- proteins a. are charged b. they can only pass through channels c. are in about the same concentration in the cytosol and ECF d. too large e. are synthesized outside the cell, and carriers only transport them into the cell
ANS: D PTS: 1 DIF: Comprehension
Collagen a. provides tensile strength to the cytoskeleton b. is most abundant in tissues that stretch and then recoil c. forms the intercellular filaments of desmosomes d. is the most abundant protein in the ECM e. all of these
ANS: D PTS: 1 DIF: Comprehension
Glucose may pass through a plasma membrane using all of the following methods EXCEPT a. cotransport b. secondary active transport c. facilitated diffusion d. simple diffusion e. symport
ANS: D PTS: 1 DIF: Comprehension
Movement of a substance up a gradient can occur through a. the GLUT carrier b. a facilitated diffusion carrier c. an aquaporin d. the SGLT carrier e. a membrane channel
ANS: D PTS: 1 DIF: Comprehension
Select the correct statement about a ribosome. a. It contains DNA. b. It synthesizes amino acids. c. It is often functional while attached to a nonmembranous organelle. d. It contains proteins that are synthesized at other ribosomes. e. All of the above statements are correct.
ANS: D PTS: 1 DIF: Comprehension
Select the last step for synaptic signaling when the action potential arrives at the axon terminal of a presynaptic neuron. a. A neurotransmitter is released by exocytosis. b. Calcium flows in the synaptic knob. c. The neurotransmitter combines with a protein receptor on the subsynaptic membrane. d. The permeability is altered in a postsynaptic neuron. e. Sodium influx occurs at the axon terminals
ANS: D PTS: 1 DIF: Comprehension
The complexes within electron transport chains a. are "circuits" for small amounts of electricity to pass through b. contain NADH that transports electrons c. transport H+ into the mitochondrial matrix d. are responsible for transporting electrons and hydrogen ions e. perform all of the above functions
ANS: D PTS: 1 DIF: Comprehension
The internal environment a. is not in direct contact with the body's cells b. consists of the intracellular fluid c. must be maintained at absolutely unchanging composition, temperature, and volume for survival of the body d. is in direct contact with the body's cells and consists of the extracellular fluid e. consists of the intracellular fluid and must be maintained at absolutely unchanging composition, temperature, and volume for survival of the body
ANS: D PTS: 1 DIF: Comprehension
The rate of carrier-mediated transport is limited by a. the glycocalyx b. osmolarity c. tonicity d. competition with other molecules e. the number of protein channels present in the membrane
ANS: D PTS: 1 DIF: Comprehension
Which statement about membrane proteins is incorrect? a. Channels are water-filled pathways. b. Channels are not highly selective. c. Carriers are highly selective. d. CAMs serve as binding sites for specific ions. e. Proteins may work in conjunction with carbohydrates to provide recognition of "self."
ANS: D PTS: 1 DIF: Comprehension
Which statement about the rate of diffusion through a lipid bilayer membrane is incorrect? a. Smaller substances diffuse faster than larger substances. b. Lipid-soluble items diffuse faster than water-soluble items. c. Items diffuse through narrow membranes faster than through thick membranes. d. The presence of microvilli decreases the rate of diffusion. e. A greater concentration gradient causes faster diffusion.
ANS: D PTS: 1 DIF: Comprehension
ATP synthase a. pumps H+ ions into the intermembrane space b. transports oxygen c. accepts H+ ions from NADH d. is not part of the ETS e. uses ATP to pump H+ out of the mitochondrial matrix
ANS: D PTS: 1 DIF: Knowledge
According to Fick's law of diffusion, which of the following changes would decrease the rate of net diffusion of "X" across a membrane? a. An increase in the X's concentration gradient b. An increase in the permeability of the membrane to X c. An increase in the surface area of the membrane d. An increase in the thickness of the membrane e. A decrease in the size of X
ANS: D PTS: 1 DIF: Knowledge
Because of the presence of both activation and inactivation gates, voltage-gated Na+ channels can a. be closed but capable of opening b. be activated c. be closed and not capable of opening d. exhibit all of the above events e. exhibit only the a and b events
ANS: D PTS: 1 DIF: Knowledge
Docking markers are most closely associated with a. the nucleus b. mitochondria c. DNA d. Golgi complexes e. the ETS
ANS: D PTS: 1 DIF: Knowledge
Glucose enters some cells a. through primary active transport b. through secondary active transport c. through facilitated diffusion d. all of the above processes e. through A and C only
ANS: D PTS: 1 DIF: Knowledge
Glycolysis a. yields two molecules of ATP for each molecule of glucose processed b. yields two molecules of NADH when converting one glucose into two pyruvates c. does not take place in the mitochondrion d. all of these e. yields two molecules of ATP for each molecule of glucose processed, and yields two molecules of NADH when converting one glucose into two pyruvates
ANS: D PTS: 1 DIF: Knowledge
Identify the correct statement(s) about stem cells. a. They are undifferentiated embryonic cells. b. They may reproduce many times. c. Their daughter cells may differentiate into a number of different specialized cell types. d. All of the above. e. None of the above.
ANS: D PTS: 1 DIF: Knowledge
Identify the true statement(s). a. Kinesin always moves toward a centriole. b. Dynein always moves toward the plasma membrane. c. Dynein is responsible for movement of microvilli. d. Myosin motors move along actin proteins. e. Myosin motors move along actin proteins and Dynein always moves toward the plasma membrane.
ANS: D PTS: 1 DIF: Knowledge
In a human cell, DNA may be found within a. the nucleus b. mitochondria c. the cytoplasm d. all of the above e. none of the above
ANS: D PTS: 1 DIF: Knowledge
In divergence, a. many presynaptic neurons synapse with one postsynaptic cell b. one dendrite contacts many presynaptic neurons c. action potentials initiated in the axon diminish as they spread to axon terminals d. one axon synapses with many other cells e. many axons spread out from one cell body
ANS: D PTS: 1 DIF: Knowledge
Integrins a. create a filamentous meshwork in the inner surface of the membrane b. act as membrane-bounded enzymes c. are used for cell recognition purposes d. span the membrane and link the plasma membrane and the cell's surrounding e. do not exhibit any of the above characteristics
ANS: D PTS: 1 DIF: Knowledge
Neuromodulators a. bind to receptors at synapses b. contribute directly to EPSPs c. contribute directly to IPSPs d. may influence neurotransmitter production e. speed up contiguous impulse conduction
ANS: D PTS: 1 DIF: Knowledge
Select the incorrect statement about connective tissue. a. Bone is an example. b. Blood is an example. c. Elastin may be found in the extracellular material. d. It has tightly-packed cells. e. It is a primary tissue type.
ANS: D PTS: 1 DIF: Knowledge
Select the neuropeptide. a. acetylcholine b. dopamine c. epinephrine d. cholecystokinin e. glycine
ANS: D PTS: 1 DIF: Knowledge
Select the substance that promotes cell adhesion. a. GLUT b. collagen c. elastin d. fibronectin e. glycolipid
ANS: D PTS: 1 DIF: Knowledge
The form of endocytosis in which whole cells such as bacteria are brought in is a. exocytosis b. pinocytosis c. receptor-mediated endocytosis d. phagocytosis e. mitosis
ANS: D PTS: 1 DIF: Knowledge
The relative refractory period occurs after the action potential is complete because of a. the lingering inactivation of the voltage-gated Na+ channels b. the slowness of the voltage-gated K+ channels c. the action of the sodium-potassium pumps d. both a and b e. both b and c
ANS: D PTS: 1 DIF: Knowledge
When comparing saltatory conduction to contiguous conduction, saltatory conduction a. is the only method that occurs along both dendrites and axons b. is the only method that utilizes a positive feedback cycle c. requires more Na+-K+ activity after repolarization is complete d. causes the loss of fewer K+ ions during repolarization e. occurs along unmyelinated axons
ANS: D PTS: 1 DIF: Knowledge
Which of the following is least related to a neuromodulator? a. axonal transport b. dense-core vesicle c. cholecystokinin d. synaptic vesicle e. neuropeptide
ANS: D PTS: 1 DIF: Knowledge
Which of the following is/are found in all cells of excitable and nonexcitable tissues? a. a threshold potential b. a resting membrane potential c. gated ion channels d. all of the above characteristics e. mechanically-gated channels
ANS: D PTS: 1 DIF: Knowledge
Which statement about a graded potential is false? a. It can be a depolarization. b. It can be a hyperpolarization. c. It can be summated. d. It has a refractory period. e. It occurs in a specialized area of the membrane.
ANS: D PTS: 1 DIF: Knowledge
Which statement about the plasma membrane is true? a. It appears trilaminar under a light microscope. b. Its glycocalyx serves as receptor sites for binding chemical messengers in the ECF. c. It is impermeable to lipid-soluble substances. d. Some of its carriers transport ions. e. Its channels are impermeable to any substance smaller than 0.8 nm in diameter.
ANS: D PTS: 1 DIF: Knowledge
Which statement is not accurate about the absolute refractory period? a. Another stimulus, regardless of its strength, cannot initiate another action potential during this period b. During this period, voltage-gated Na+ channels open, then close but are inactivated c. Immediately following this period, the membrane can experience another action potential if the stimulus is strong enough d. This period occurs during the after hyperpolarization phase of the action potential e. This period ensures a unidirectional spread of the action potential down a nerve fiber
ANS: D PTS: 1 DIF: Knowledge
Which statement would be true at a membrane during its resting membrane potential? a. It is more permeable to K+ than to Na+. b. It is highly permeable to Cl-. c. The electrical gradient for Cl- opposes its concentration gradient d. All of the above statements are true. e. Only b and c are true
ANS: D PTS: 1 DIF: Knowledge
Which structure is not associated with the secretion of proteins produced by ER? a. Golgi complex b. smooth ER c. transport vesicles d. lysosomal membrane e. plasma membrane
ANS: D PTS: 1 DIF: Knowledge
____________________ are cell connections that utilize CAMs to hold adjacent cells together while being anchor to intermediate filaments of each cell's cytoskeleton.
ANS: Desmosomes PTS: 1 DIF: Knowledge
____________________ is a protein responsible for pinching off an endocytic vesicle.
ANS: Dynamin PTS: 1 DIF: Knowledge
If a typical body cell is placed into a 1% saline solution, the cell a. will gain more water than it loses. b. will have a higher osmotic pressure than the ECF. c. will have a lower hydrostatic pressure than the ECF. d. will gain and lose water at the same rate. e. will have a lower osmolarity than the saline solution.
ANS: E PTS: 1 DIF: Analysis
If an excitatory neuron and an inhibitory neuron both stimulate the same postsynaptic neuron simultaneously, what can you know for sure is happening in the postsynaptic neuron? a. it would likely reach threshold b. its permeability to cations and anions would decrease c. its resting membrane potential would increase d. it would be experiencing temporal summation e. increased permeability to cations
ANS: E PTS: 1 DIF: Analysis
Match the term to the correct description. a. collagen b. elastin c. fibronectin d. keratin Provides tensile strength to the ECM
1. ANS: A PTS: 1 DIF: Knowledge
Indicate whether the following physiological event represents: a. feedforward control b. negative feedback control c. positive feedback control X increases the production of Y and Y decreases the production of X.
1. ANS: B PTS: 1 DIF: Application
Match the term to its description. a. plasma membrane b. nucleus c. cytoplasm d. cytosol e. organelles f. cytoskeleton Houses the cell's DNA
1. ANS: B PTS: 1 DIF: Knowledge
Select the incorrect association. a. ATP/high-energy bonds b. electron transport chain/mitochondrion c. glycolysis/anaerobic d. glycolysis/cytosol e. pyruvate/five-carbon molecule
ANS: E PTS: 1 DIF: Analysis
Which of the following is not associated with an extracellular chemical binding with a membrane-bound receptor? a. Decreased activity within a certain cell b. Activation of an ATPase c. A change in shape of a transmembrane protein d. Increased activity within a certain cell e. Opening of a sodium channel that allows Na+ to diffuse out of the cell
ANS: E PTS: 1 DIF: Analysis
Which statement is false? a. Binding of Na+ to the SGLT carrier increases the carrier's affinity for ATP. b. The release of Na+ from the SGLT carrier increases the carrier's affinity for glucose. c. Glucose enters the luminal side of an intestinal cell through a GLUT carrier. d. The GLUT carrier is a symporter. e. The SGLT carrier is a symporter.
ANS: E PTS: 1 DIF: Analysis
If neuron X is repeatedly stimulating neuron Z with an excitatory neurotransmitter, then a. several simultaneous action potentials might be initiated on neuron Z b. the membrane potential on neuron Z would increase c. spatial summation would be occurring on neuron Z d. the postsynaptic neuron in this situation would have to reach threshold voltage e. none of the above would have to occur
ANS: E PTS: 1 DIF: Application
How does a depolarizing graded potential lead to the propagation of action potentials?
A depolarizing graded potential does not reverse the polarity of the cell membrane, but it moves the potential closer to threshold voltage. If threshold voltage is reached, voltage-gated Na+ channels in that region will open, causing an action potential in which the inside border of the membrane becomes positive. This reversal in polarity causes the membrane potential in the adjacent region to reach threshold, which causes voltage-gated Na+ channels in that region to open. Thus, an action potential in one region will change the voltage in an adjacent region significantly enough to generate an action potential there. This process continues and allows the action potentials to be propagated along the plasma membrane. PTS: 1 DIF: Knowledge
What are four ways in which drugs might influence the nervous system at the neuronal level?
A drug or disease agent might:(1) alter the synthesis, transport, storage, or release of a neurotransmitter; (2) modify the way in which the neurotransmitter interacts with the postsynaptic receptor; (3) influence the neurotransmitters' reuptake or destruction; and (4) replace or substitute for a deficient neurotransmitter. PTS: 1 DIF: Application
If solution A has a higher concentration of solute particles than solution B and if these solutions are separated by a semipermeable membrane, then there will be a net movement of water a. into solution B since B has a lower osmotic pressure than solution A b. into solution B since B will have a higher hydrostatic pressure than solution A c. into solution B since the osmolarity of B is less than that in solution A d. into solution A since B has a higher osmotic pressure than solution A e. into solution A since A has a lower concentration of water than solution B
ANS: E PTS: 1 DIF: Application
Neuron A and neuron B release a minimal amount of neurotransmitter simultaneously onto neuron C, causing neuron C to experience an action potential. This is an example of a. temporal summation b. spatial summation c. convergence d. both a and c e. both b and c
ANS: E PTS: 1 DIF: Application
A single phospholipid in the plasma membrane a. has its hydrophobic end next to either the ECF or the cytosol b. spans the entire width of the membrane c. can function as carrier molecule d. remains in the same location indefinitely e. does not exhibit any of the above characteristics
ANS: E PTS: 1 DIF: Comprehension
All of the following transport certain substances from regions of high concentration to low concentration except a. carriers b. facilitated diffusion c. SGLT d. GLUT e. Ca2+ pump
ANS: E PTS: 1 DIF: Comprehension
At the peak of an action potential, a. the diffusion of Na+ through voltage-gated channels ceases b. the concentration gradient for K+ promotes the movement of this ion out of the cell c. K+ permeability greatly increases d. the electrical gradient promotes the diffusion of K+ out of the cell e. all of the above are true
ANS: E PTS: 1 DIF: Comprehension
Chemiosmosis a. releases O2 onto a water molecule at the end of the ETS b. pumps H+ ions into the mitochondrial matrix c. transfers hydrogens from the ETS to NAD+ d. generates GTP, which is then converted into ATP e. does not perform any of the above functions
ANS: E PTS: 1 DIF: Comprehension
During anaerobic conditions, a. more pyruvate is formed from lactate. b. the degradation of glucose cannot proceed beyond the Krebs cycle. c. mitochondrial processing of nutrient molecules takes place. d. the ETS continues to function, but the Krebs cycle does not. e. FAD is not converted to FADH2.
ANS: E PTS: 1 DIF: Comprehension
During osmosis, a. water moves away from the solution with the higher osmotic pressure. b. water moves into a hypotonic solution. c. the solute moves against its concentration gradient. d. all of the above events would occur. e. none of the above events would occur.
ANS: E PTS: 1 DIF: Comprehension
Facilitated diffusion a. involves a membrane channel b. requires the cell to expend expenditure c. is how glucose in the intestinal lumen moves into cells in the digestive lining d. is a form of active transport e. None of the above
ANS: E PTS: 1 DIF: Comprehension
If a human cell is placed into solution X, containing water and a nonpenetrating solute, then a. water will diffuse into solution X until the cytosol and solution X are isotonic. b. water will diffuse across the membrane until a state of equilibrium is established. c. water will diffuse into the cell until stopped by an opposing hydrostatic pressure in the cytosol. d. neither the cell nor solution X will experience a net gain of water. e. it is not possible to predict what will happen.
ANS: E PTS: 1 DIF: Comprehension
Microtubules a. serve as a mechanical stiffener for microvilli b. form neurofilaments, which degrade in Lou Gehrig's disease c. form non-muscle contractile assemblies d. play an important structural role in parts of the cell subject to mechanical stress e. is responsible for nuclear division but not cytoplasmic division
ANS: E PTS: 1 DIF: Comprehension
Select the first step for synaptic signaling when the action potential arrives at the axon terminal of a presynaptic neuron. a. A neurotransmitter is released by exocytosis. b. Calcium flows into the synaptic knob. c. The neurotransmitter combines with a protein receptor on the subsynaptic membrane. d. The permeability is altered in a postsynaptic neuron. e. The axon terminal depolarizes.
ANS: E PTS: 1 DIF: Comprehension
The period following an action potential during which a membrane cannot experience another action potential a. is the absolute refractory period b. occurs during the time after the Na+ gates have opened until they are restored to their "closed but capable of opening" state c. prevents the action potential from spreading back over the part of the membrane where the impulse has just passed d. includes the time when Na+ gates are in a "closed and not capable of opening" state e. includes all of the above
ANS: E PTS: 1 DIF: Comprehension
Which of the following characteristics is least related to steroid hormones? a. Binds to intracellular receptor b. Transported bound in the blood c. May bind to hormone response element d. Stimulate protein synthesis e. Utilize a G protein
ANS: E PTS: 1 DIF: Comprehension
Which of the following does not always involve the plasma membrane? a. endocytosis b. secretion c. formation of an endocytic vesicle d. pinocytosis e. vesicle formation
ANS: E PTS: 1 DIF: Comprehension
Which of the following is correct? a. Exocytosis decreases the surface area of the plasma membrane. b. Endocytosis can help remove cytoplasmic debris from inside the cell. c. Exocytosis is triggered by the binding of a particle in the ECF to a receptor site on the plasma membrane. d. Exocytosis involves passive movement of material out of the cell. e. None of these.
ANS: E PTS: 1 DIF: Comprehension
Which of the following is responsible for the falling phase of an action potential? a. opening of Na+ gates b. Na+-K+ pump restoring the ions to their original locations c. greatly increased permeability to Na+ d. Na+ efflux e. none of these
ANS: E PTS: 1 DIF: Comprehension
Which statement about cells is incorrect? a. They are the smallest things that can be alive. b. They are generally too small to be seen with the unaided eye. c. They are highly organized. d. Cells in large dogs are the same size as cells in smaller dogs. e. Most cells in dogs are quite different than cells in humans.
ANS: E PTS: 1 DIF: Comprehension
Which statement about movement into the cytosol is false? a. If glucose and sodium can both combine with the same carrier, the presence of one of these molecules decreases the rate of entry of the other. b. In simple diffusion, the rate of entry of an ion is directly proportional to its concentration in the cytosol. c. When a glucose symporter becomes saturated, the rate of glucose entry decreases. d. None of the statements are false. e. All of the statements are false.
ANS: E PTS: 1 DIF: Comprehension
Which statement is true? a. Mitochondria are primarily sites where anaerobic respiration occurs. b. Vaults are inclusions in the cytoplasm that transport DNA. c. Peroxisomes are membranous sacs that contain hydrolytic enzymes. d. Ribosomes are membranous organelles that synthesize proteins. e. None of the statements are true.
ANS: E PTS: 1 DIF: Comprehension
An action potential on a neuron develops when a. threshold voltage is reached on an axon b. voltage-gated Na+ channels open c. spatial or temporal summation of graded potentials occurs to a great enough degree d. the axon hillock reaches threshold voltage e. any of the above events occur
ANS: E PTS: 1 DIF: Knowledge
Calcium is stored mainly in the ____ system. a. digestive b. endocrine c. integumentary d. muscular e. skeletal
ANS: E PTS: 1 DIF: Knowledge
Drugs may influence synaptic transmission by a. altering the formation of neurotransmitters b. blocking neurotransmitter reuptake c. blocking receptors d. blocking channels e. all of the above
ANS: E PTS: 1 DIF: Knowledge
Extracellular fluid a. is the internal environment of the body b. is outside the cells but inside the body c. consists of the plasma and interstitial fluid d. exhibits a dynamic steady state in regard to composition, temperature, and volume e. is described by all of the above statements
ANS: E PTS: 1 DIF: Knowledge
Identify a second-messenger. a. Insulin b. G protein c. G protein coupled receptor d. Adenylyl cyclase e. None of the above
ANS: E PTS: 1 DIF: Knowledge
Identify the characteristics associated with endocrine glands. a. lack ducts b. secrete chemicals directly into the blood c. derived from epithelial tissue d. include the parathyroids e. all of these
ANS: E PTS: 1 DIF: Knowledge
Identify the item that does not enter a cell through a coated pit: a. insulin b. iron c. cholesterol d. vitamin B12 e. cargo protein
ANS: E PTS: 1 DIF: Knowledge
In most excitable cells, the rising phase of the action potential is due to a. calcium efflux b. potassium efflux c. chloride influx d. potassium influx e. sodium influx
ANS: E PTS: 1 DIF: Knowledge
Myelinated axons conduct impulses much faster because a. the myelin insulates the axon b. ion channels only have to open at the nodes c. voltage is not lost along myelinated areas d. saltatory conduction occurs e. all of the above are true
ANS: E PTS: 1 DIF: Knowledge
NADH is a. an energy carrier b. used in cellular respiration c. produced in glycolysis d. produced in the citric acid cycle e. important in all of the above
ANS: E PTS: 1 DIF: Knowledge
Nicotimamide adenine dinucleotide (NAD) is a. used in glycolysis and in the Krebs cycle b. found in the cytosol c. a hydrogen carrier molecule d. found in the mitochondrion e. characterized by all of the above
ANS: E PTS: 1 DIF: Knowledge
Receptor sites on the outer surface of the plasma membrane are made of a. CAMs b. carbohydrate c. lipid d. keratin e. proteins
ANS: E PTS: 1 DIF: Knowledge
Ribosomes a. are the only sites where proteins are made b. contain protein in their chemical makeup c. contain RNA in their chemical makeup d. consist of subunits that are constructed inside the nucleus e. are characterized by all of the above
ANS: E PTS: 1 DIF: Knowledge
Select the incorrect statement about the action potential. a. It has an all-or-none characteristic b. It has a refractory period c. It is triggered by depolarization to threshold d. It occurs along a plasma membrane e. It speeds up transmission by summation
ANS: E PTS: 1 DIF: Knowledge
Select the structure that is not located in the cytosol of the cell. a. ER b. Golgi complex c. lysosome d. mitochondrion e. nucleolus
ANS: E PTS: 1 DIF: Knowledge
The normal direction for the movement of an action potential along part of a neuron is from a. axon hillock to cell body b. axon terminal to collateral axon c. axon to dendrite d. cell body to receptor e. dendrite to cell body
ANS: E PTS: 1 DIF: Knowledge
The resting membrane potential of a typical nerve cell is ____ mV. a. -60 b. +70 c. -90 d. -50 e. -70
ANS: E PTS: 1 DIF: Knowledge
What is responsible for development of the resting membrane potential? a. Leak channels b. Gated channels c. Ion pumps d. both a and b e. both a and c
ANS: E PTS: 1 DIF: Knowledge
Where do the citric acid cycle reactions occur? a. cytoplasm b. cytosol c. inner-mitochondrial membrane d. outer-mitochondrial membrane e. mitochondrial matrix
ANS: E PTS: 1 DIF: Knowledge
Where is CO2 released in the aerobic cellular respiration process? a. glycolysis b. electron transport chain c. Krebs cycle d. just prior to pyruvate entering the Krebs cycle e. Krebs cycle and just prior to pyruvate entering the Krebs cycle
ANS: E PTS: 1 DIF: Knowledge
Which characteristic of the Golgi complex is incorrect? a. It sorts and directs products to their final destination. b. It is a membranous organelle surrounded by cytosol. c. It produces lysosomes. d. It modifies proteins made at the rough ER. e. It receives secretory vesicles coming from the ER.
ANS: E PTS: 1 DIF: Knowledge
Which characteristic regarding microfilaments is incorrect? a. They serve as mechanical stiffeners for microvilli. b. They are composed of actin subunits. c. They are the smallest elements of the cytoskeleton. d. They are involved in cell locomotion. e. They form mitotic spindles.
ANS: E PTS: 1 DIF: Knowledge
Which organelle is not membrane-bound? a. Golgi body b. lysosome c. mitochondrion d. RER e. ribosome
ANS: E PTS: 1 DIF: Knowledge
Which statement(s) would be true about the resting membrane potential? a. It is closer to the equilibrium potential for Na+ than to the equilibrium potential for K+ b. It is closer to the equilibrium potential for K+ than to the equilibrium potential for Na+ c. It is about the same as the equilibrium potential for Cl- d. Only a and b are true e. Only b and c
ANS: E PTS: 1 DIF: Knowledge
____ are adhering junctions, ____ are impermeable junctions, and ____ are communicating junctions. a. Tight junctions, gap junctions, desmosomes b. Desmosomes, gap junctions, tight junctions c. Gap junctions, desmosomes, tight junctions d. Gap junctions, tight junctions, desmosomes e. Desmosomes, tight junctions, gap junctions
ANS: E PTS: 1 DIF: Knowledge
____________________ is a rubber-like protein found in tissues of organs such as the lungs.
ANS: Elastin PTS: 1 DIF: Knowledge
____________________ stem cells are undifferentiated cells that result from the early divisions of a fertilized egg and ultimately give rise to all specialized cells of the body.
ANS: Embryonic stem PTS: 1 DIF: Knowledge
____________________ glands secrete through ducts, whereas ____________________ glands secrete directly into the blood.
ANS: Exocrine, endocrine PTS: 1 DIF: Knowledge
____________________ refers to the process of an intracellular vesicle fusing with the plasma membrane, then opening and emptying its contents to the exterior.
ANS: Exocytosis PTS: 1 DIF: Knowledge
T/F The time following an action potential during which a membrane cannot respond to another stimulus, regardless of its strength, is called the relative refractory period.
ANS: F Absolute refractory period PTS: 1 DIF: Knowledge
T/F Along a neuron, an action potential normally travels from the dendrites to the cell body to the axon.
ANS: F Dendrites and cell bodies do not conduct action potentials. PTS: 1 DIF: Knowledge
T/F A solution having a higher osmolarity will always gain water from a solution having a lower osmolarity.
ANS: F Depends on the hydrostatic pressure in the two solutions. PTS: 1 DIF: Comprehension
T/F If water is moving back and forth at the same rate between two solutions, the two solutions have to be isotonic to one another.
ANS: F Depends on the hydrostatic pressure in the two solutions. PTS: 1 DIF: Comprehension
T/F A solution containing 300 mOsm/L will always gain water from a solution containing only 250 mOsm/L.
ANS: F Depends on the hydrostatic pressures in the two solutions PTS: 1 DIF: Comprehension
T/F If an electrical gradient is present for a given substance, the substance may be able to get through the membrane without going through a carrier or channel.
ANS: F PTS: 1 DIF: Analysis
T/F Placing pure water around cells causes the cells to swell because the cytosol has a lower osmotic pressure than the pure water.
ANS: F PTS: 1 DIF: Application
T/F A lipophilic chemical messenger uses a second messenger system to alter the activity of a target cell.
ANS: F PTS: 1 DIF: Comprehension
T/F A carrier molecule moves from the ECF side to cytosol side of the membrane as it transports material into the cell.
ANS: F PTS: 1 DIF: Comprehension
T/F A mechanistic explanation of why a person breathes is to obtain oxygen.
ANS: F PTS: 1 DIF: Comprehension
T/F A membrane potential of -50 mV is greater than a membrane potential of -70 mV.
ANS: F PTS: 1 DIF: Comprehension
T/F A postsynaptic neuron can either excite or inhibit a presynaptic neuron.
ANS: F PTS: 1 DIF: Comprehension
T/F A solution having a lower osmolarity will always gain water from a solution having a higher osmolarity.
ANS: F PTS: 1 DIF: Comprehension
T/F A stimulus that is too weak to depolarize the membrane to threshold produces an action potential that is weaker than normal.
ANS: F PTS: 1 DIF: Comprehension
T/F According to the Nernst equation, the equilibrium potential for a given ion decreases as the difference in concentration of the ion outside and inside the cell increases.
ANS: F PTS: 1 DIF: Comprehension
T/F Action potentials can be summed.
ANS: F PTS: 1 DIF: Comprehension
T/F Action potentials may result from hyperpolarization or depolarization.
ANS: F PTS: 1 DIF: Comprehension
T/F After an action potential has occurred, there is more Na+ inside the cell than outside the cell (before any Na+-K+ pump activity has taken place).
ANS: F PTS: 1 DIF: Comprehension
T/F Amplification is a phenomenon associated with hormones derived from cholesterol.
ANS: F PTS: 1 DIF: Comprehension
T/F At equilibrium, when no net diffusion of Na+ or K+ is occurring through the membrane, Na+-K+ pumps do not have to pump Na+ or K+.
ANS: F PTS: 1 DIF: Comprehension
T/F At resting membrane potential, sodium and potassium ions are no longer moving across the membrane.
ANS: F PTS: 1 DIF: Comprehension
T/F CaM is more closely associated with lipophilic hormones than with hydrophilic hormones.
ANS: F PTS: 1 DIF: Comprehension
T/F Dephosphorylation of the Na+-K+ pump causes three Na+ ions to move out of a cell against a concentration gradient.
ANS: F PTS: 1 DIF: Comprehension
T/F Dynamin is synthesized inside endosomes and is responsible for pinching off the endosome from the plasma membrane.
ANS: F PTS: 1 DIF: Comprehension
T/F Exocytosis involves expelling a substance when the plasma membrane unites with a special carrier protein.
ANS: F PTS: 1 DIF: Comprehension
T/F Factors that are homeostatically regulated are maintained at a constant, fixed level unless disease is present.
ANS: F PTS: 1 DIF: Comprehension
T/F Gap junctions contain carrier proteins that transport ions from one cell into another cell.
ANS: F PTS: 1 DIF: Comprehension
T/F Hormones derived from cholesterol are bound to proteins in the blood and primarily alter preexisting proteins via second-messenger systems.
ANS: F PTS: 1 DIF: Comprehension
T/F If a candy bar is likened to a single glucose molecule, then a pyruvate molecule would be likened to two candy bars.
ANS: F PTS: 1 DIF: Comprehension
T/F If a cell's Na+-K+ pumps quit working, all of that cell's secondary active transporters would quit working immediately.
ANS: F PTS: 1 DIF: Comprehension
T/F If a pluripotent cell differentiates to become a skin cell, it may revert back to its pluripotent condition and then become a muscle cell.
ANS: F PTS: 1 DIF: Comprehension
T/F Insulin is a hormone that is secreted into the lumen of the intestine in response to the presence of food.
ANS: F PTS: 1 DIF: Comprehension
T/F Large protein anions do not leave the cell because there is no concentration or electrical gradient to drive it outward.
ANS: F PTS: 1 DIF: Comprehension
T/F Leak channels for sodium are closed during the resting potential but open with appropriate stimulation.
ANS: F PTS: 1 DIF: Comprehension
T/F Lysosomes synthesize hydrolase enzymes.
ANS: F PTS: 1 DIF: Comprehension
T/F Most endocrine glands secrete paracrine substances that function as neurohormones.
ANS: F PTS: 1 DIF: Comprehension
T/F Most homeostatic mechanisms operate on the principle of positive feedback.
ANS: F PTS: 1 DIF: Comprehension
T/F Negative feedback operates to prevent any change in the value of a controlled factor in the body.
ANS: F PTS: 1 DIF: Comprehension
T/F Neuropeptides are mainly neuromodulators that function as second messengers in cells that respond to hydrophilic hormones.
ANS: F PTS: 1 DIF: Comprehension
T/F One "strong" stimulus can cause more than one action potential, but a "weak" stimulus may or may not generate an action potential.
ANS: F PTS: 1 DIF: Comprehension
T/F Opening a gated channel that allows Na+ to diffuse through the plasma membrane would cause the membrane potential to increase.
ANS: F PTS: 1 DIF: Comprehension
T/F Oxygen molecules are used in the Krebs cycle and at the end of the ETS.
ANS: F PTS: 1 DIF: Comprehension
T/F Peroxisomes are nonmembranous organelles that generate and degrade hydrogen peroxide.
ANS: F PTS: 1 DIF: Comprehension
T/F Pinocytosis refers to the process of a cell engulfing ECF, and this process increases the cell's surface area.
ANS: F PTS: 1 DIF: Comprehension
T/F Potassium ions are attracted toward a more positively charged area along an electrical gradient, while chloride ions are attracted toward a more negatively charged area.
ANS: F PTS: 1 DIF: Comprehension
T/F Presynaptic inhibition is brought about when dendrites of a postsynaptic neuron alter the signals sent from an axon terminal of a presynaptic neuron.
ANS: F PTS: 1 DIF: Comprehension
T/F Since lysosomes cannot make their own enzymes, those enzymes must be synthesized in the Golgi complex prior to the lysosome's formation.
ANS: F PTS: 1 DIF: Comprehension
T/F The Golgi complex synthesizes recognition markers that recognize and attract specific sorting signals.
ANS: F PTS: 1 DIF: Comprehension
T/F The lipids within the ER's membrane must synthesize additional lipid molecules so the ER can grow as a cell grows.
ANS: F PTS: 1 DIF: Comprehension
T/F The rough ER synthesizes proteins within their interconnected sacs.
ANS: F PTS: 1 DIF: Comprehension
T/F The simple fact that exercising muscles use more O2 is an example of negative feedback.
ANS: F PTS: 1 DIF: Comprehension
T/F The tyrosine-kinase pathway is activated in response to certain lipophilic hormones, whereas the second messenger pathway is activated in response to certain hydrophilic hormones.
ANS: F PTS: 1 DIF: Comprehension
T/F The way in which the nervous system affects a person's heart rate is an example of intrinsic control since both the nervous system and the heart are inside the body.
ANS: F PTS: 1 DIF: Comprehension
T/F To sustain life, the internal environment must be maintained in an absolutely unchanging state.
ANS: F PTS: 1 DIF: Comprehension
T/F Unassisted membrane transport can sometimes require the cell to expend energy.
ANS: F PTS: 1 DIF: Comprehension
T/F With secondary active transport, sodium ions move along a concentration gradient but against an electrical gradient.
ANS: F PTS: 1 DIF: Comprehension
T/F A calcium pump is a secondary active transporter.
ANS: F PTS: 1 DIF: Knowledge
T/F A given synapse may produce EPSPs at one time and IPSPs at another time.
ANS: F PTS: 1 DIF: Knowledge
T/F A single pluripotent cell without dividing can differentiate into more than one kind of mature body cell.
ANS: F PTS: 1 DIF: Knowledge
T/F A spike is another name for the axon of a neuron.
ANS: F PTS: 1 DIF: Knowledge
T/F All cells that are not pluripotent can reproduce.
ANS: F PTS: 1 DIF: Knowledge
T/F Amyotrophic lateral sclerosis is likely associated with the disruption of microtubules and microfilaments within motor neurons.
ANS: F PTS: 1 DIF: Knowledge
T/F Because of the presence of tight junctions, passage of materials across an epithelial barrier must take place between the cells, not through them.
ANS: F PTS: 1 DIF: Knowledge
T/F Blood is a type of connective tissue that contains small fibers of elastin protein in the extracellular material called plasma.
ANS: F PTS: 1 DIF: Knowledge
T/F Cadherins are docking-marker acceptors to which secretory vesicles bind prior to exocytosis.
ANS: F PTS: 1 DIF: Knowledge
T/F Calcium and sodium ions are in a higher concentration in the ECF than in the cytosol, whereas potassium and chloride ions are in a higher concentration in the cytosol.
ANS: F PTS: 1 DIF: Knowledge
T/F Coatomers form around endosomes formed during receptor-mediated endocytosis.
ANS: F PTS: 1 DIF: Knowledge
T/F Cocaine blocks the binding of dopamine at postsynaptic membranes.
ANS: F PTS: 1 DIF: Knowledge
T/F Common second messengers include cAMP, acetylcholine, and calcium ions.
ANS: F PTS: 1 DIF: Knowledge
T/F Connexons are carbohydrate building blocks of gap junctions that allow ions to pass from the cytosol of one cell into the cytosol of an adjacent cell.
ANS: F PTS: 1 DIF: Knowledge
T/F Cytokinesis is the division of the nucleus during mitosis.
ANS: F PTS: 1 DIF: Knowledge
T/F DNA's genetic code for a particular protein is transcribed into rRNA.
ANS: F PTS: 1 DIF: Knowledge
T/F Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.
ANS: F PTS: 1 DIF: Knowledge
T/F During the relative refractory period, a neuron can experience hyperpolarization but not depolarization.
ANS: F PTS: 1 DIF: Knowledge
T/F Dynein is a mitochondrial enzyme.
ANS: F PTS: 1 DIF: Knowledge
T/F Electron microscopes are about 1000 times more powerful than light microscopes.
ANS: F PTS: 1 DIF: Knowledge
T/F Endocrine glands secrete hormones through ducts into the blood.
ANS: F PTS: 1 DIF: Knowledge
T/F Endocytosis can only be accomplished by phagocytosis and pinocytosis.
ANS: F PTS: 1 DIF: Knowledge
T/F Enzymes are carbohydrates that speed up chemical reactions in the body.
ANS: F PTS: 1 DIF: Knowledge
T/F Exocrine glands are the only structures in the body capable of secretion.
ANS: F PTS: 1 DIF: Knowledge
T/F Feedforward mechanisms bring about a response in reaction to a change in a regulated variable.
ANS: F PTS: 1 DIF: Knowledge
T/F Fibronectin is a strong carbohydrate in the extracellular matrix of connective tissues that holds adjacent cells together.
ANS: F PTS: 1 DIF: Knowledge
T/F For graded potentials, the magnitude of triggering is coded for in frequency rather than amplitude of depolarizations.
ANS: F PTS: 1 DIF: Knowledge
T/F Glycolysis utilizes most of the stored energy in glucose when synthesizing ATP molecules.
ANS: F PTS: 1 DIF: Knowledge
T/F Highly differentiated tissues such as nervous and cardiac muscle are incapable of reproduction because they are pluripotent.
ANS: F PTS: 1 DIF: Knowledge
T/F In cystic fibrosis, defective chloride channels allow too many chloride ions to enter the cell, causing the cell to become hypertonic to the ECF and swell.
ANS: F PTS: 1 DIF: Knowledge
T/F Intermediate filaments account for about 85% of the protein present in muscle and liver cells.
ANS: F PTS: 1 DIF: Knowledge
T/F Lipid synthesis does not occur in the rough ER.
ANS: F PTS: 1 DIF: Knowledge
T/F Most gases and small ions are highly soluble in lipids and can, therefore, pass easily between phospholipid molecules in the plasma membrane.
ANS: F PTS: 1 DIF: Knowledge
T/F Multiple sclerosis develops from a buildup of myelin of a neuron.
ANS: F PTS: 1 DIF: Knowledge
T/F Myelinated fibers throughout the nervous system can regenerate when cut, but unmyelinated fibers cannot regenerate.
ANS: F PTS: 1 DIF: Knowledge
T/F Na+ ions can move from the ECF into the ICF by passing through secondary active transport carriers, simple diffusion channels, and the sodium-potassium pumps.
ANS: F PTS: 1 DIF: Knowledge
T/F Nerve fiber is another name for a dendrite on a neuron.
ANS: F PTS: 1 DIF: Knowledge
T/F Oligodendrocytes are specialized to conduct electrical impulses to neurons.
ANS: F PTS: 1 DIF: Knowledge
T/F Oligodendrocytes form a regeneration tube to guide a regenerating nerve fiber to its proper destination.
ANS: F PTS: 1 DIF: Knowledge
T/F Only neurons and muscle cells establish resting membrane potentials.
ANS: F PTS: 1 DIF: Knowledge
T/F Oxygen gas, cholesterol, and glucose molecules are lipid-soluble, whereas proteins, amino acids, and ions are water-soluble.
ANS: F PTS: 1 DIF: Knowledge
T/F Peroxisomes arise from vesicles produced at the rough ER, while lysosomes arise from vesicles produced at the Golgi complex.
ANS: F PTS: 1 DIF: Knowledge
T/F Phagocytosis is a specialized form of endocytosis used primarily for bringing ECF into the cytosol.
ANS: F PTS: 1 DIF: Knowledge
T/F Preprohormones give rise to lipophilic hormones.
ANS: F PTS: 1 DIF: Knowledge
T/F Primary cilia are responsible for moving dust from the respiratory tract.
ANS: F PTS: 1 DIF: Knowledge
T/F RER is most abundant in cells specialized for steroid production.
ANS: F PTS: 1 DIF: Knowledge
T/F Scurvy is caused by a vitamin C deficiency that prevents the proper development of desmosomes; hence, tissue cells do not hold together.
ANS: F PTS: 1 DIF: Knowledge
T/F Secretion involves v-SNARE markers located on the plasma membrane.
ANS: F PTS: 1 DIF: Knowledge
T/F Secretory vesicles are taken into a cell by means of phagocytosis.
ANS: F PTS: 1 DIF: Knowledge
T/F Sheets of epithelial cells are joined by gap junctions.
ANS: F PTS: 1 DIF: Knowledge
T/F Skeletal muscle cells have numerous mitochondria within their endoplasmic reticulum and this special organization is called the mitochondrial reticulum.
ANS: F PTS: 1 DIF: Knowledge
T/F Some enzymes inside the rough ER may pass through the ER's membrane and be used within the cytosol, but most enzymes used in the cytosol are made at free ribsomes.
ANS: F PTS: 1 DIF: Knowledge
T/F The Krebs cycle occurs within the mitochondria while the citric acid cycle occurs in the cytosol.
ANS: F PTS: 1 DIF: Knowledge
T/F The Nernst equation takes into account the permeabilities and concentration gradients for all permeable ions in order to calculate the membrane's equilibrium potential.
ANS: F PTS: 1 DIF: Knowledge
T/F The conduction velocity of a nerve impulse is slower in myelinated fibers than in unmyelinated fibers because myelin acts as an insulator that slows down the flow of current.
ANS: F PTS: 1 DIF: Knowledge
T/F The cytoplasm is the same as the ICF.
ANS: F PTS: 1 DIF: Knowledge
T/F The dark lines in the trilaminar appearance of the plasma membrane are likely caused by the preferential staining of the hydrophobic, nonpolar regions of the membrane constituents.
ANS: F PTS: 1 DIF: Knowledge
T/F The epidermis that covers the skin is a simple organ.
ANS: F PTS: 1 DIF: Knowledge
T/F The external environment is found outside cells but inside the body.
ANS: F PTS: 1 DIF: Knowledge
T/F The integumentary, nervous, and endocrine systems are the only systems involved in regulating body temperature.
ANS: F PTS: 1 DIF: Knowledge
T/F The myelin covering the axon promotes the leakage of ions from an axon, but it promotes conservation of ATP in the neuron.
ANS: F PTS: 1 DIF: Knowledge
T/F The nodes of Ranvier are Schwann cells or oligodendrocytes that wrap themselves "jelly roll fashion" around the axon.
ANS: F PTS: 1 DIF: Knowledge
T/F The only time the contents of secretory vesicles come in contact with the cytosol is when the vesicle joins with the plasma membrane.
ANS: F PTS: 1 DIF: Knowledge
T/F The plasma surrounds and bathes all of the body's cells.
ANS: F PTS: 1 DIF: Knowledge
T/F The primary barrier to passage of water-soluble substances across the plasma membrane is the outer layer of carbohydrates.
ANS: F PTS: 1 DIF: Knowledge
T/F The surface carbohydrates within the plasma membrane serve as cell adhesion molecules (CAMs), which cells use to grip hold of one another and to surrounding connective-tissue fibers.
ANS: F PTS: 1 DIF: Knowledge
T/F The two primary organelles involved in detoxifying harmful substances are the peroxisomes and the Golgi complex.
ANS: F PTS: 1 DIF: Knowledge
T/F Threshold potential is the peak potential achieved during an action potential.
ANS: F PTS: 1 DIF: Knowledge
T/F Thyroid hormone is derived from an amino acid, which makes it soluble in water and able to utilize a second messenger system.
ANS: F PTS: 1 DIF: Knowledge
T/F Tissues are composed of two or more types of cells organized to perform a particular function or functions.
ANS: F PTS: 1 DIF: Knowledge
T/F Under an electron microscope, the plasma membrane appears as a trilaminar structure consisting of two light layers separated by a dark middle layer.
ANS: F PTS: 1 DIF: Knowledge
T/F Vaults are presumably descendants of primitive bacterial cells.
ANS: F PTS: 1 DIF: Knowledge
____________________ are cell-to-cell connections through which materials can pass from the cytosol of one cell into the cytosol of an adjacent cell.
ANS: Gap junctions PTS: 1 DIF: Knowledge
The ____________________ is the central packaging and discharge site for molecules to be transported from the cell.
ANS: Golgi apparatus PTS: 1 DIF: Knowledge
A common antiporter transports ____________________ ions out of the cell while it transports ____________________ ions into the cell.
ANS: H+, Na+ PTS: 1 DIF: Knowledge
____________________ refers to maintenance of a relatively stable internal environment.
ANS: Homeostasis PTS: 1 DIF: Knowledge
At the end of repolarization, the newly opened channels for ____________________ ions close.
ANS: K+ PTS: 1 DIF: Knowledge
Opening a chemically-gated ____________________ channel or ____________________ channel will increase the membrane potential of a plasma membrane.
ANS: K+, Cl- PTS: 1 DIF: Comprehension
____________________ is the most abundant protein inside skin cells, where it comprises the intermediate filaments of the cytoskeleton.
ANS: Keratin PTS: 1 DIF: Knowledge
________ is a motor molecule that travels toward the "plus" end of a microtubule, whereas ________ travels toward the "minus" end..
ANS: Kinesin, dynein PTS: 1 DIF: Knowledge
____________________ refers to a separation of opposite charges across the membrane.
ANS: Membrane potential PTS: 1 DIF: Knowledge
__________ are part of the cytoskeleton and serve as mechanical stiffeners for microvilli.
ANS: Microfilaments PTS: 1 DIF: Knowledge
____________________ are the dominant structural and functional components of cilia and flagella.
ANS: Microtubules PTS: 1 DIF: Knowledge
____________________ tissue is composed of cells specialized for contraction and force generation.
ANS: Muscle PTS: 1 DIF: Knowledge
____________________ is a motor molecule that moves toward the "plus" end of a cytoskeletal filament made of actin.
ANS: Myosin PTS: 1 DIF: Knowledge
Opening channels that allow ____________________ ions or ____________________ ions result in depolarization of the plasma membrane.
ANS: Na+, Ca2+ PTS: 1 DIF: Comprehension
The ____________________ pump moves two ____________________ ions into the cell for every three ____________________ ions it moves out the cell.
ANS: Na+-K+, Na+, K+ PTS: 1 DIF: Knowledge
The ____________________ equation equates the equilibrium potential for an ion with the ion's concentration difference outside and inside the cell.
ANS: Nernst PTS: 1 DIF: Knowledge
____________________ cells are specialized to send electrical signals.
ANS: Nerve PTS: 1 DIF: Knowledge
____________________ are released into the blood by neurosecretory neurons.
ANS: Neurohormones PTS: 1 DIF: Knowledge
____________________ are chemical messengers that bind to neuronal receptors at nonsynaptic sites and alter the effectiveness of ongoing synaptic activity.
ANS: Neuromodulators PTS: 1 DIF: Knowledge
____________________ are chemical messengers that do not cause the formation of EPSPs or IPSPs but rather bring about long-term changes that depress or enhance the action of the synapse.
ANS: Neuromodulators PTS: 1 DIF: Knowledge
____________________ move through the axon before being released from the synaptic knob and then bind to nonsynaptic receptors; whereas, ____________________ are made in the cytosol of the synaptic knob and after their release bind to subsynaptic receptors.
ANS: Neuromodulators, neurotransmitters PTS: 1 DIF: Knowledge
____________________ are composed of two or more types of primary tissue organized to perform a particular function or functions.
ANS: Organs PTS: 1 DIF: Knowledge
____________________ serves as the final electron acceptor in the electron transport system.
ANS: Oxygen PTS: 1 DIF: Knowledge
____________________ are local chemical messengers that exert an effect only on neighboring cells in the immediate environment.
ANS: Paracrines PTS: 1 DIF: Knowledge
____________________ refers to the abnormal functioning of the body associated with disease.
ANS: Pathophysiology PTS: 1 DIF: Knowledge
____________________ refers to the transfer of a phosphate group from ATP to a protein, thereby bringing about a change in the shape and function of the protein.
ANS: Phosphorylation PTS: 1 DIF: Knowledge
____________________ is the hindrance to electrical charge movement.
ANS: Resistance PTS: 1 DIF: Knowledge
____________________ cells form myelin around neurons in the PNS, whereas ____________________ form myelin around neurons in the CNS.
ANS: Schwann, oligodendrocytes PTS: 1 DIF: Knowledge
____________________ cells are not specialized for a specific function but can divide to give rise to highly specialized cells.
ANS: Stem PTS: 1 DIF: Knowledge
T/F If a cell begins to swell after being placed into a salt solution, the salt solution must have a lower osmotic pressure than the cytosol.
ANS: T PTS: 1 DIF: Application
T/F A balance of IPSPs and EPSPs will negate each other so that the grand postsynaptic potential is essentially unaltered.
ANS: T PTS: 1 DIF: Comprehension
T/F A non-mechanistic explanation of why a person sweats is to cool off.
ANS: T PTS: 1 DIF: Comprehension
T/F A single neuron may be presynaptic to one group of neurons and postsynaptic to another group of neurons.
ANS: T PTS: 1 DIF: Comprehension
T/F Adenylyl cyclase and diacylglycerol are more associated with hydrophilic hormones than with lipophilic hormones.
ANS: T PTS: 1 DIF: Comprehension
T/F Amplification is more closely associated with hydrophilic hormones than with lipophilic hormones.
ANS: T PTS: 1 DIF: Comprehension
T/F Because a solution of lower solute concentration has a higher concentration of water, it exerts a lower osmotic pressure than does a solution with a higher solute concentration.
ANS: T PTS: 1 DIF: Comprehension
T/F Cholera toxin is more disruptive to the action of hydrophilic hormones than to the action of lipophilic hormones.
ANS: T PTS: 1 DIF: Comprehension
T/F DNA in the nucleus has the genetic instructions to make dynein.
ANS: T PTS: 1 DIF: Comprehension
T/F During the steady state, the concentration and electrical gradients for K+ are in opposition to each other and exactly balance each other so there is no net movement of K+.
ANS: T PTS: 1 DIF: Comprehension
T/F G proteins in the plasma membrane of certain cells may become activated in response to the binding of water-soluble hormones, whereas protein phosphatases are continuously active in these cells.
ANS: T PTS: 1 DIF: Comprehension
T/F Increased permeability of the postsynaptic cell to Cl- lessens the likelihood that the postsynaptic cell will undergo an action potential.
ANS: T PTS: 1 DIF: Comprehension
T/F Net sodium movement into the cell occurs passively, whereas net sodium movement out of the cell occurs actively.
ANS: T PTS: 1 DIF: Comprehension
T/F Opening a potassium channel during the resting membrane potential would cause the inside border of the plasma membrane to become more negative.
ANS: T PTS: 1 DIF: Comprehension
T/F Opening a potassium channel during the resting potential would cause potassium ions to move along their concentration gradient but against the electrical gradient.
ANS: T PTS: 1 DIF: Comprehension
T/F Opening a sodium channel during the resting potential would cause sodium ions to move along an electrical gradient and along a concentration gradient.
ANS: T PTS: 1 DIF: Comprehension
T/F Osmosis does not occur if there is no concentration gradients for water and solutes on opposite sides of a semipermeable membrane.
ANS: T PTS: 1 DIF: Comprehension
T/F Proteins synthesized at the endoplasmic reticulum become permanently separated from the cytosol as soon as they have been synthesized.
ANS: T PTS: 1 DIF: Comprehension
T/F Sodium-potassium pumps indirectly provide the energy source for SGLT carriers in intestinal cells.
ANS: T PTS: 1 DIF: Comprehension
T/F The grand postsynaptic potential depends on the sum of activity of the presynaptic inputs.
ANS: T PTS: 1 DIF: Comprehension
T/F The refractory period prevents action potentials from spreading back over the part of the membrane where the impulse has just passed.
ANS: T PTS: 1 DIF: Comprehension
T/F The respiratory system removes carbon dioxide transported to it by the blood.
ANS: T PTS: 1 DIF: Comprehension
T/F Under normal conditions, the movement of potassium into a cell always requires the splitting of ATP.
ANS: T PTS: 1 DIF: Comprehension
T/F With negative feedback, a control system's output counteracts the input into the system.
ANS: T PTS: 1 DIF: Comprehension
T/F With positive feedback, a control system's input and output continue to enhance each other.
ANS: T PTS: 1 DIF: Comprehension
T/F cAMP and phospholipase are more closely associated with the action of water-soluble hormones than with the action of lipid-soluble hormones.
ANS: T PTS: 1 DIF: Comprehension
T/F A pair of electrons released from one NADH molecule causes the formation of more ATP molecules than do a pair of electrons released from a FADH2.
ANS: T PTS: 1 DIF: Knowledge
T/F ATP synthase is located in the inner mitochondrial membrane.
ANS: T PTS: 1 DIF: Knowledge
T/F According to the fluid mosaic model, the plasma membrane consists primarily of a bilayer of mobile phospholipid molecules studded with an ever-changing mosaic pattern of proteins.
ANS: T PTS: 1 DIF: Knowledge
T/F Action potentials are initiated at the axon hillock region because it has the lowest threshold voltage.
ANS: T PTS: 1 DIF: Knowledge
T/F All cell organelles are renewable.
ANS: T PTS: 1 DIF: Knowledge
T/F Amoeboid movement is accomplished by alternate assembly and disassembly of actin filaments.
ANS: T PTS: 1 DIF: Knowledge
T/F An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter.
ANS: T PTS: 1 DIF: Knowledge
T/F At resting membrane potential, passive and active forces exactly balance each other so there is no net movement of ions across the membrane.
ANS: T PTS: 1 DIF: Knowledge
T/F Carbon dioxide exits cells by simple diffusion between phospholipid molecules in the plasma membrane.
ANS: T PTS: 1 DIF: Knowledge
T/F Carriers that perform facilitated diffusion or secondary active transport of glucose do not split ATP.
ANS: T PTS: 1 DIF: Knowledge
T/F Cells eliminate carbon dioxide as a waste product.
ANS: T PTS: 1 DIF: Knowledge
T/F Classical neurotransmitters and neuropeptides are sometimes co-secreted from the same axon terminal.
ANS: T PTS: 1 DIF: Knowledge
T/F Coated vesicles bud off the Golgi complex and contain various proteins.
ANS: T PTS: 1 DIF: Knowledge
T/F During the absolute refractory period, the voltage-gated Na+ channels are not capable of opening again in response to another triggering event.
ANS: T PTS: 1 DIF: Knowledge
T/F During the resting potential, the membrane is more permeable to potassium ions than to sodium ions.
ANS: T PTS: 1 DIF: Knowledge
T/F Fibronectin is a protein that helps hold cells in position within tissues.
ANS: T PTS: 1 DIF: Knowledge
T/F Gap junctions connect the cytoplasm of a cell with the cytoplasm of an adjacent cell.
ANS: T PTS: 1 DIF: Knowledge
T/F Gap junctions play an important role in transmission of impulses for heart contraction.
ANS: T PTS: 1 DIF: Knowledge
T/F Glands are formed during embryonic development by pockets of epithelial tissue that dip inward from the surface.
ANS: T PTS: 1 DIF: Knowledge
T/F If two similar molecules can both combine with the same carrier, the presence of one of these molecules decreases the rate of entry of the other.
ANS: T PTS: 1 DIF: Knowledge
T/F In a graded potential, the direction of current flow is designated by the movement of positive charges.
ANS: T PTS: 1 DIF: Knowledge
T/F In the lipid bilayer of the plasma membrane, the hydrophobic tails of the phospholipids orient toward the center of the membrane, away from water.
ANS: T PTS: 1 DIF: Knowledge
T/F In the plasma membrane, the polar ends of the phospholipid molecules are hydrophilic.
ANS: T PTS: 1 DIF: Knowledge
T/F Lipophilic hormones bind to hormone response elements on DNA, which then initiates steps in the formation of new protein molecules.
ANS: T PTS: 1 DIF: Knowledge
T/F Local current flows locally between active and adjacent inactive areas of the cell membrane, thereby decreasing the potential in the inactive area to threshold.
ANS: T PTS: 1 DIF: Knowledge
T/F Molecules greater than 0.8 nm in diameter are too large to pass from the ECF into the cytosol through channels.
ANS: T PTS: 1 DIF: Knowledge
T/F Most intermediary metabolism is accomplished in the cytosol.
ANS: T PTS: 1 DIF: Knowledge
T/F Most of a membrane potential is established by the passive movement of different cations into and out of a cell.
ANS: T PTS: 1 DIF: Knowledge
T/F Motor molecules cannot transport vesicles along intermediate filaments of the cytoskeleton.
ANS: T PTS: 1 DIF: Knowledge
T/F Multiple sclerosis is an autoimmune disease in which the body's defense system erroneously attacks the myelin sheath surrounding myelinated nerve fibers.
ANS: T PTS: 1 DIF: Knowledge
T/F One organ can belong to more than one body system.
ANS: T PTS: 1 DIF: Knowledge
T/F Oxidative phosphorylation generates more ATP per glucose molecule than does glycolysis.
ANS: T PTS: 1 DIF: Knowledge
T/F Phosphorylation of a carrier can alter the affinity of its binding sites, accompanied by a change in its conformation.
ANS: T PTS: 1 DIF: Knowledge
T/F Positive feedback moves a controlled variable even further away from a steady state.
ANS: T PTS: 1 DIF: Knowledge
T/F Schwann cells promote axonal growth, while oligodendrocytes inhibit it.
ANS: T PTS: 1 DIF: Knowledge
T/F Secretion in response to appropriate stimulation refers to the release of specific products that have, in large part, been synthesized by the cell.
ANS: T PTS: 1 DIF: Knowledge
T/F Secretory vesicles are about 200 times larger than transport vesicles.
ANS: T PTS: 1 DIF: Knowledge
T/F Some activities performed by the muscular and nervous systems are not directed toward maintaining homeostasis.
ANS: T PTS: 1 DIF: Knowledge
T/F Some carrier molecules do not require energy to accomplish transport of a substance across the membrane.
ANS: T PTS: 1 DIF: Knowledge
T/F Some cell adhesion molecules are peripheral proteins and some are integral proteins.
ANS: T PTS: 1 DIF: Knowledge
T/F The Golgi complex is functionally connected to the ER.
ANS: T PTS: 1 DIF: Knowledge
T/F The Na+ and K+ channels that open and close during an action potential are voltage-gated channels.
ANS: T PTS: 1 DIF: Knowledge
T/F The SGLT and GLUT carriers both move a substance down a concentration gradient.
ANS: T PTS: 1 DIF: Knowledge
T/F The SGLT and GLUT carriers do not split ATP.
ANS: T PTS: 1 DIF: Knowledge
T/F The amount of smooth ER within liver cells may change dramatically over a period of days, depending on the amount of drug detoxification that is required.
ANS: T PTS: 1 DIF: Knowledge
T/F The carbohydrate found in plasma membranes is believed to be involved in the aggregation of cells to form tissue.
ANS: T PTS: 1 DIF: Knowledge
T/F The concentration of salt in the extracellular fluid influences how water enters and leaves cells.
ANS: T PTS: 1 DIF: Knowledge
T/F The cytoplasm includes everything between the plasma membrane and nucleus of a cell.
ANS: T PTS: 1 DIF: Knowledge
T/F The diffusion of potassium ions reestablishes the resting membrane potential in a neuron immediately after it develops an action potential.
ANS: T PTS: 1 DIF: Knowledge
T/F The endocrine system relies on the circulatory system for the transport of hormones.
ANS: T PTS: 1 DIF: Knowledge
T/F The endoplasmic reticulum is one continuous organelle consisting of many tubules and cisternae.
ANS: T PTS: 1 DIF: Knowledge
T/F The hydrophobic interior of the lipid bilayer of the plasma membrane blocks the passage of water-soluble substances.
ANS: T PTS: 1 DIF: Knowledge
T/F The integumentary system contains specialized organs called sweat glands, which are important in regulating body temperature.
ANS: T PTS: 1 DIF: Knowledge
T/F The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.
ANS: T PTS: 1 DIF: Knowledge
T/F The nucleus indirectly governs most cellular activities by directing the kinds and amounts of various enzymes and other proteins that are produced by the cell.
ANS: T PTS: 1 DIF: Knowledge
T/F The passive current flow of a graded potential fades quickly.
ANS: T PTS: 1 DIF: Knowledge
T/F The protective, waterproof outer layer of skin is formed by the tough skeleton of intermediate filaments that persist after the surface skin cells die.
ANS: T PTS: 1 DIF: Knowledge
T/F The refractory period limits the frequency of action potentials.
ANS: T PTS: 1 DIF: Knowledge
T/F The rough endoplasmic reticulum is most abundant in cells specialized for protein secretion, whereas smooth endoplasmic reticulum is abundant in cells that specialize in lipid metabolism.
ANS: T PTS: 1 DIF: Knowledge
____________________ stem cells are partially differentiated, harvested from adults, and can become highly differentiated, specialized cell types.
ANS: Tissue-specific PTS: 1 DIF: Knowledge
____________________ RNA carries amino acids to the sites of protein synthesis in the cell.
ANS: Transfer PTS: 1 DIF: Knowledge
____________________ are organelles that may possibly transport ribosomal subunits out of the nucleus.
ANS: Vaults PTS: 1 DIF: Knowledge
____________________-soluble hormones must use ____________________ systems to exert their effects on target cells.
ANS: Water, second-messenger PTS: 1 DIF: Comprehension
Microfilaments are comprised of the protein ____________________, and are used as highways by motor molecules called ____________________.
ANS: actin, myosin PTS: 1 DIF: Knowledge
A transport maximum is associated with carriers that perform ____________________ or ____________________ in the cell membrane.
ANS: active transport, facilitated diffusion PTS: 1 DIF: Knowledge
ADP and P are formed from the breakdown of the molecule ____________________.
ANS: adenosine triphosphate (ATP) PTS: 1 DIF: Knowledge
One disease caused by neurofilament abnormalities is ____________________.
ANS: amyotropic lateral sclerosis PTS: 1 DIF: Knowledge
The longest part of a typical neuron is the ____________________.
ANS: axon or nerve fiber PTS: 1 DIF: Knowledge
The ____________________ or ____________________ of a neuron is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.
ANS: axon, nerve fiber PTS: 1 DIF: Knowledge
A cilium or flagellum originates from a structure called a(n) ____________________.
ANS: basal body PTS: 1 DIF: Knowledge
____________________ is a second messenger formed when a membrane enzyme called a cyclase becomes activated by a G protein.
ANS: cAMP PTS: 1 DIF: Knowledge
Cell adhesion proteins (CAMs) include ____________________ and ____________________.
ANS: cadherins, integrins PTS: 1 DIF: Knowledge
Axon terminals possess ____________________ voltage-gated channels that when operational induce neurotransmitter release.
ANS: calcium PTS: 1 DIF: Knowledge
In muscle cells, the sarcoplasmic reticulum is a storage site for ________.
ANS: calcium PTS: 1 DIF: Knowledge
The two types of ____________________ transport include active transport and ____________________.
ANS: carrier-mediated, facilitated diffusion PTS: 1 DIF: Knowledge
Ions can pass into or out of the cell only through ____________________ and ____________________ in the plasma membrane.
ANS: carriers, channels PTS: 1 DIF: Knowledge
The smallest unit capable of carrying out the processes associated with life is the ____________________.
ANS: cell PTS: 1 DIF: Knowledge
Simple diffusion of different substances through the cell membrane can occur through the phospholipid region and through ____________________.
ANS: channels PTS: 1 DIF: Knowledge
A plasma membrane is polarized if it separates particles with an opposite ____________________.
ANS: charge PTS: 1 DIF: Knowledge
The synthesis of ATP as a result of H+ flowing through an ATP synthase is called _________.
ANS: chemiosmosis PTS: 1 DIF: Knowledge
A deficiency in channels that allow ____________________ ions to pass through cell membranes is responsible for cystic fibrosis.
ANS: chloride PTS: 1 DIF: Knowledge
At the equilibrium potential for an ion, its ____________________ gradient is exactly counterbalanced by its ____________________ gradient.
ANS: concentration, electrical PTS: 1 DIF: Knowledge
For a neuron, the axon is its _______ zone and an axon terminal is its ______ zone.
ANS: conducting, output PTS: 1 DIF: Knowledge
The neuronal relationship where many presynaptic cells terminate on a single postsynaptic cell is called ____________________.
ANS: convergence PTS: 1 DIF: Knowledge
An increase in the size of the ____________________ of a nerve fiber, along with the amount of ____________________ around the fiber both increase its rate of conduction.
ANS: diameter, myelin PTS: 1 DIF: Knowledge
The neuronal relationship where a single presynaptic cell branches to terminate on many other cells is called ____________________.
ANS: divergence PTS: 1 DIF: Knowledge
Vesicles bind to ____________________ acceptors on the plasma membrane prior to exocytosis
ANS: docking-marker PTS: 1 DIF: Knowledge
The GLUT carrier moves glucose molecules ____________________ their concentration gradient while the SGLT carrier moves glucose _________________their concentration gradient.
ANS: down, up PTS: 1 DIF: Knowledge
On a microtubule, the motor molecule called ____________________ moves toward a centriole.
ANS: dynein PTS: 1 DIF: Knowledge
The ____________________ system consists of all hormone-secreting tissues.
ANS: endocrine PTS: 1 DIF: Knowledge
Foreign material to be attacked by lysosomal enzymes is brought into the cell by the process of ____________________.
ANS: endocytosis or phagocytosis PTS: 1 DIF: Knowledge
The membrane potential that exists when the concentration and electrical gradients for a given ion exactly counterbalance each other is known as the ____________________.
ANS: equilibrium potential PTS: 1 DIF: Knowledge
The internal environment consists of the ____________________, which is made up of ____________________; the fluid portion of the blood; and ____________________, which surrounds and bathes all cells.
ANS: extracellular fluid, plasma, interstitial fluid PTS: 1 DIF: Knowledge
The most common inclusion within cells of adipose tissue is ____________________.
ANS: fat PTS: 1 DIF: Knowledge
The model of the plasma membrane as a lipid bilayer studded and penetrated by proteins is known as the ____________________ model of membrane structure.
ANS: fluid mosaic PTS: 1 DIF: Knowledge
The SGLT carrier moves ____________________ molecules uphill against a concentration gradient while moving ____________________ ions down a concentration gradient.
ANS: glucose, Na+ PTS: 1 DIF: Knowledge
The SGLT carrier transports ______________ molecules against their concentration gradient while moving _____________ ions down their concentration gradient.
ANS: glucose, Na+ PTS: 1 DIF: Knowledge
Membrane carbohydrates in the plasma membrane combine with other molecules to form glycoproteins and ____________________.
ANS: glycolipids PTS: 1 DIF: Knowledge
In facilitated diffusion, particles move from a(n) ____________________ concentration to a(n) ____________________ concentration.
ANS: higher, lower PTS: 1 DIF: Knowledge
In a second messenger system, the first messenger is the __________.
ANS: hormone PTS: 1 DIF: Knowledge
The chemiosmotic mechanism involves the transport of ____________________ ions across the inner membrane of the ____________________.
ANS: hydrogen, mitochondrion PTS: 1 DIF: Knowledge
The tonsils are part of the ____________________ system.
ANS: immune or lymphatic PTS: 1 DIF: Knowledge
In many cells, the hormone called ____________________ promotes the insertion of glucose carriers into the plasma membranes.
ANS: insulin PTS: 1 DIF: Knowledge
The body cells are in direct contact with, and make life-sustaining exchanges with, the ____________________.
ANS: internal environment (extracellular fluid) PTS: 1 DIF: Knowledge
The fluid contained within all of the cells of the body is known collectively as ____________________, and the fluid outside of the cells is referred to as ____________________.
ANS: intracellular fluid, extracellular fluid PTS: 1 DIF: Knowledge
A solution containing the same concentration of solute particles as human cells is said to be ____________________ to the cell.
ANS: isotonic PTS: 1 DIF: Knowledge
In active transport, a substance moves from an area of ____________________ concentration to an area of ____________________ concentration.
ANS: lower, higher PTS: 1 DIF: Knowledge
Organelles called ____________________ contain ____________________ enzymes that are capable of digesting and removing unwanted debris from the cell.
ANS: lysosomes, hydrolytic PTS: 1 DIF: Knowledge
The chemical called ____________________ along axons reduces resistance and, hence, increases impulse velocity.
ANS: myelin PTS: 1 DIF: Knowledge
If after making a bad grade on an exam causes a student to study harder in order to make a better grade on the next exam, the student's response to making the bad grade would be an example of ___________________ feedback.
ANS: negative PTS: 1 DIF: Comprehension
Opening a sodium channel during the resting membrane potential will cause the potential to become less ____________________.
ANS: negative PTS: 1 DIF: Comprehension
During the resting membrane potential, the inside of a neuron has a net ____________________ charge.
ANS: negative PTS: 1 DIF: Knowledge
The ____________________ system controls and coordinates bodily activities that require swift responses, especially to changes in the external environment.
ANS: nervous PTS: 1 DIF: Knowledge
The two major control systems of the body are the ____________________ and the ____________________.
ANS: nervous system, endocrine system PTS: 1 DIF: Knowledge
A single nerve cell, also called a ____________________, typically consists of the following three basic parts: ____________________, ____________________, and ____________________.
ANS: neuron, cell body, dendrites, axon PTS: 1 DIF: Knowledge
The two major parts of the cell's interior are the ____________________ and the ____________________.
ANS: nucleus, cytoplasm PTS: 1 DIF: Knowledge
Net diffusion of water down its own concentration gradient toward an area of higher solute concentration is known as ____________________.
ANS: osmosis PTS: 1 DIF: 1
Enzymes referred to as ____________________ enzymes use O2 to strip hydrogen from organic molecules.
ANS: oxidative PTS: 1 DIF: Knowledge
The metabolism of acetyl CoA into the citric acid cycle depends on the presence of ____________________ gas in the mitochondrion.
ANS: oxygen PTS: 1 DIF: Knowledge
Of the lipids in the plasma membrane, ____________________ are most abundant, with lesser amounts of ____________________.
ANS: phospholipids, cholesterol PTS: 1 DIF: Knowledge
The ____________________ is the liquid part of the blood.
ANS: plasma PTS: 1 DIF: Knowledge
The three major subdivisions of a cell are the ____________________, the ____________________, and the ____________________.
ANS: plasma membrane, nucleus, cytoplasm PTS: 1 DIF: Knowledge
The ribosomes of the rough ER synthesize ____________________, whereas its membranous walls contain enzymes essential for the synthesis of ____________________.
ANS: proteins, lipids PTS: 1 DIF: Knowledge
One glucose molecule is converted into two molecules of ____________________ by the end of glycolysis.
ANS: pyruvic acid PTS: 1 DIF: Knowledge
Schwann cells stimulate the formation of a(n) ____________________ tube to rebuild damaged neurons.
ANS: regeneration PTS: 1 DIF: Knowledge
In ____________________ diffusion, water-soluble materials move through specific channels in the cell membrane.
ANS: simple PTS: 1 DIF: Knowledge
A neuron starts to depolarize when _________________ ions move into the cell.
ANS: sodium PTS: 1 DIF: Comprehension
Glucose moves against its concentration gradient through the cell membrane by passing through carriers that simultaneously transport ____________________ ions.
ANS: sodium PTS: 1 DIF: Knowledge
When EPSPs occurring simultaneously from two different presynaptic inputs add together or sum to bring the postsynaptic cell to threshold, it is called ____________________ summation.
ANS: spatial PTS: 1 DIF: Knowledge
The three characteristics that determine the kind and amount of material that can be moved across a membrane by carrier-mediated transport are ____________________, ____________________, and ____________________.
ANS: specificity, saturation, competition PTS: 1 DIF: Knowledge
Surrounding a blood cell with a 0.5% NaCl solution would cause the cell to ____________________, because this NaCl solution is ____________________ to the cell.
ANS: swell, hypotonic PTS: 1 DIF: Application
Secondary active transport in which two substances pass through the membrane in the same direction is called ____________________.
ANS: symport (or cotransport) PTS: 1 DIF: Knowledge
A(n) ____________________ is a collection of organs that perform related functions and interact to accomplish a common activity that is essential for survival of the whole body.
ANS: system or organ system PTS: 1 DIF: Knowledge
One presynaptic neuron can only produce ____________________ summation on a postsynaptic neuron.
ANS: temporal PTS: 1 DIF: Comprehension
When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________ summation.
ANS: temporal PTS: 1 DIF: Knowledge
At ____________________ potential, typically around -55 mv, rapid depolarization occurs.
ANS: threshold PTS: 1 DIF: Knowledge
"Kiss" sites are associated with cell-to-cell connections called ____________________.
ANS: tight junctions PTS: 1 DIF: Knowledge
Cell connections called ____________________ force materials to pass through cells and not between them.
ANS: tight junctions PTS: 1 DIF: Knowledge
The process by which incoming signals are conveyed into a target cell, where they are transformed into a certain cellular response is called signal _________.
ANS: transduction PTS: 1 DIF: Knowledge
The ____________________ refers to the maximum amount of a substance that can be transported across the plasma membrane via a carrier in a given time.
ANS: transport maximum (Tm) PTS: 1 DIF: Knowledge
The ____________________ system eliminates waste products other than carbon dioxide and plays a key role in regulating the volume, electrolyte composition, and acidity of the extracellular fluid.
ANS: urinary PTS: 1 DIF: Knowledge
Endocytosis and exocytosis are both examples of ____________________ transport.
ANS: vesicular PTS: 1 DIF: Knowledge
The decomposition of hydrogen peroxide produces the substances ____________________ and ____________________.
ANS: water, oxygen PTS: 1 DIF: Knowledge
Describe the movement of vesicles along microtubules in the cytoskeleton. Include the following in your answer: microtubules, tubulin, kinesin, dynein, plus end, minus end, and centriole.
Centrioles form microtubules, which are made of tubulin proteins. The microtubules radiate out from the centrioles, with their "minus" ends at the centrioles and their "plus" ends farthest away from the centriole. Motor molecules attach to vesicles and then move along the microtubules. Kinesin can only move toward the plus end of the microtubule; therefore, they always move away from the centriole. Dynein can only move toward the minus end of the microtubule; therefore, they always move toward the centriole.
How is ATP synthesized via electron transport and oxidative phosphorylation? Be sure to include the following items in your answer: electrons, glycolysis, Krebs cycle, NADH, FADH2, hydrogen ion pump, intermembrane space, ATP synthase, ATP, and oxygen.
Electrons (in hydrogen atoms) that are stripped out of reactions in glycolysis and the Krebs cycle are transported to the ETS via electron carriers (NADH and FADH2). The electrons are passed along carriers within the ETS and the energy they release is used by hydrogen ion pumps to move hydrogen ions from the mitochondrial matrix into the intermembrane space of the mitochondrion. Hydrogen ions then diffuse back into the matrix through special enzymes called ATP synthases. The movement of H+ through the enzymes energizes the enzymes, allowing them to phosphorylate ADP to form ATP. Oxygen serves as the final electron acceptor in the ETS, thus allowing the ETS to continue accepting electrons from NADH and FADH2. PTS: 1 DIF: Comprehension
e
Label "3" identifies a. a myosin motor moving along a microtubule b. a kinesin motor moving along a microfilament c. a dynein motor moving along a microtubule d. a dynein motor moving away from a centriole e. none of these
Describe the structure and function of cilia and flagella. Be sure to include the following in your answer: basal body, doublets, triplets, dynein, fused, unfused, and "9+2."
Flagella and cilia are motile extensions of a cell, and they contain nine fused pairs of microtubules (each pair is a doublet) arranged in a ring around two single unfused microtubules, yielding a "9+2" arrangement. Dynein motor molecules walk along adjacent microtubule doublets, causing the doublets to slide past each other; this is responsible for the bending and stroking actions of cilia and flagella. Cilia and flagella arise from basal bodies, which are similar to centrioles and have nine fused triplets rather than doublets of microtubules and do not surround any unfused microtubules. PTS: 1 DIF: Comprehension
Describe the transport of glucose out of an intestinal cell and into the blood.
Glucose is transported from the intestinal cell into the blood via facilitated transport. The carrier for this process is called GLUT (glucose transporter). After entering the intestinal cell via the SGLT, glucose moves through the cytosol and attaches to the GLUT in the plasma membrane on the basolateral (blood) side of the cell. This causes the GLUT to change shape and transport the glucose down its concentration gradient out of the cell. The glucose then diffuses through the interstitial fluid and into the blood vessel, a process that also requires facilitated diffusion carriers. PTS: 1 DIF: Comprehension
Describe the transport of glucose from the intestinal lumen into the intestinal cells and mention how Na+-K+ pumps make this process possible.
Glucose is transported from the intestinal lumen into the intestinal cells via cotransport (secondary active transport) with Na+ ions. The symporter for this process is called SGLT (sodium-glucose transporter). A sodium ion attaches to the SGLT and increases the carrier's affinity for glucose. A glucose molecule then binds to the luminal side of the SGLT. Having a Na+ ion and glucose attached simultaneously causes the SGLT to change shape and transport the Na+ and glucose into the cell. The Na+ ion is moved down its concentration gradient, while the glucose is moved against its concentration gradient. By constantly pumping Na+ ions out of the cell, the Na+-K+ pumps in the membrane of the intestinal cell maintain a steep gradient for Na+. Therefore, Na+ ions have a greater tendency to attach to the luminal side of the SGLT, which, in turn, allows more glucose to enter the cell. PTS: 1 DIF: Comprehension
Describe two benefits of a cell carrying out anaerobic glycolysis. Be sure to include the following in your answer: pyruvate, electrons (in hydrogen atoms), oxygen, mitochondrion, Krebs cycle, ETS, and ATP.
Glycolysis produces ATP in the cytosol and does not require oxygen. Therefore, when oxygen concentrations in the cell decrease below optimum, the cell can still synthesize ATP using energy extracted from glucose. Another advantage is that glycolysis provides substrates in the form of pyruvate and high-energy electrons that can be used within the mitochondria to generate more ATP. The pyruvate is modified into acetyl CoA, which enters the Krebs cycle; and high-energy electrons (within hydrogen atoms) that are taken out of glycolysis reactions can be used to power the electron transport system, which is important for oxidative phosphorylation within the mitochondrion. PTS: 1 DIF: Comprehension
c
In beaker 2, the solution on the right side of the membrane a. has a higher osmolarity than the solution on the left side of the membrane b. will gain water from the solution on the left side of the membrane c. has a lower osmotic pressure than the solution on the left side of the membrane d. has a higher osmolarity than the solution on the left side of the membrane and will gain water from the solution on the left side of the membrane e. none of these
Describe the action of a Na+-K+ pump.
Three Na+ ions bind to the ICF side of the pump, which allows the pump to then split ATP into ADP and phosphate. The phosphate binds to the pump (i.e., the pump is phosphorylated), which then changes shape and transports the Na+ ions to the ECF. After the Na+ ions leave the pump, two K+ ions attach to the ECF side of the pump, which then causes the phosphate group to detach from the pump. Dephosphorylation causes the pump to change shape and transport the K+ ions into the cell. When the K+ ions detach from the pump, the pump is now ready to repeat the process. PTS: 1 DIF: Comprehension
Describe an action potential and explain why a region of the membrane that is in the absolute refractory period cannot experience another action potential until repolarization is complete. Include the following in your answer: voltage-gated Na+ channels, voltage-gated K+ channels, activation gate, inactivation gate, threshold voltage, increasing membrane potential, and decreasing membrane potential.
When a voltage-gated Na+ channel is at rest, its inactivation gate is open and its activation gate is closed. When threshold voltage is reached, the activation gate opens and allows Na+ ions to diffuse into the cell; this action decreases the membrane potential to the point that the potential becomes positive. At the peak of the depolarization event, the activation and inactivation gates in the Na+ channels close, but the voltage-gated K+ channels open. As K+ ions diffuse out of the cell, the membrane potential increases; i.e., the membrane repolarizes. The inactivation gate in the Na+ channels will remain shut until the membrane potential has been completely repolarized. After repolarization, the inactivation gate will reopen. Now the membrane can respond to another stimulus. PTS: 1 DIF: Comprehension
What might happen on a postsynaptic neuron if, at the same time, it receives one stimulus at an excitatory synapse located close to the axon hillock but receives two stimuli at two different inhibitory synapses, both of which are far away from the axon hillock?
Since graded potentials diminish in intensity as they travel across a membrane, the closer to the axon hillock the stimulus is applied, the greater its effect. Therefore, one excitatory stimulus generating an EPSP near the axon hillock may be intense enough to reach threshold and initiate an action potential on the postsynaptic neuron, because the two IPSPs generated by the inhibitory neurons diminish as they move toward the axon hillock and may not be able to counteract the one EPSP generated near the hillock. PTS: 1 DIF: Application
Describe how an ATP is important to the SGLT carrier.
Since the SGLT is a secondary active transporter, it does not rely on ATP directly. However, it relies on a steep concentration gradient for Na+ ions, which is maintained by the Na+-K+ pumps that use ATP directly. The SGLT binds to Na+ ions and also glucose molecules in the ECF. Only by binding to both substances can the SGLT transport them into the cell. The Na+ ions move down their concentration gradient while the glucose moves up its own gradient.
Describe what would happen to red blood cells if a person received a transfusion of distilled (pure) water.
Since the distilled water contains no solute, it would be very hypotonic to the cells. Consequently, water would rapidly enter the red blood cells causing them to swell and possibly rupture (lyse). PTS: 1 DIF: Application
Describe the concentration gradients associated with the resting membrane potential.
The cytosol contains a much higher concentration of K+ ions than the ECF, while the ECF contains a much higher concentration of Na+ ions than the cytosol. The membrane is "leakier" to the K+ ions than to the Na+ ions; therefore, more K+ ions leak out of the cell than there are Na+ ions leaking into the cell. This is partly responsible for the resting membrane potential being positive on the ECF side and negative on the ICF side of the membrane. In addition, the Na+- K+ pumps actively transport three Na+ ions out of the cell for every two K+ ions it transports into the cell. Coupling the unequal diffusion and the unequal pumping of these two cations is responsible for the establishment of the resting membrane potential. PTS: 1 DIF: Comprehension
Beginning with the chemical level and ending with the system level, compare the different levels of organization in the human body with the following things found on a page in a book: sentence, letter, word, ink in a letter, paragraph, and all paragraphs on a page.
The ink would be like the chemical level and it forms the letters, which would be like cells. Two or more letters together make up a word, which is like a tissue. Two or more words make up a sentence, which is like an organ; and two or more sentences make up a paragraph, which is like a body system. All paragraphs on a page would be like all body systems together, which make up the human body. PTS: 1 DIF: Application
Describe the pathway that newly synthesized polypeptides take on route for secretion.
The rough ER synthesizes proteins, which then make their way into the smooth ER. The smooth ER packages the proteins within transport vesicles that pass to the Golgi complex. The contents of the vesicle enter the Golgi complex where they may be modified. Eventually, the secretory products are packaged into secretory vesicles, which bud off the Golgi complex and make their way to the plasma membrane along components of the cytoskeleton. On appropriate stimulation, the secretory vesicles fuse with the plasma membrane and empty their contents into the ECF via exocytosis. PTS: 1 DIF: Comprehension
c
The structure labeled "1" a. is a microfilament b. is made of actin c. originates at a centriole d. is a "highway" for myosin motor molecules e. all of these
Describe the effects of the concentration and electrical gradients on the movement of Na+ and K+ ions through the membrane.
The unequal diffusion and unequal pumping of cations (Na+ and K+) causes the ECF side of the plasma membrane to be positively charged while the ICF side is negatively charged. As the inside border of the membrane becomes more negative, it exerts a stronger attraction for the K+ ions, which prevents an excessive amount of K+ diffusion out of the cell. Although the negative inside border has a very strong attraction for the Na+ ions in the ECF, the membrane is not very "leaky" to these ions. However, if a channel opens and allows these ions to passively move through the membrane, Na+ ions will move into the cell down its concentration gradient and down the electrical gradient (i.e., from a positive region toward a negative region). Potassium ions can diffuse out of the cell along their concentration gradient, but it would be against an electrical gradient, unless the outside border becomes negatively charged. PTS: 1 DIF: Comprehension
e
Which number identifies a structure that utilizes hydrolases to perform its function? a. 1 b. 2 c. 3 d. 4 e. 5
1
Which number identifies the site of aerobic respiration?
3
Which number identifies the structure responsible for the synthesis of proteins that end up in secretory vesicles?
3
Which number identifies the system that is primarily responsible for fighting infectious diseases?
5
Which number identifies the system that serves as a regulatory system in which the duration of activity is more important than the speed of activity?
1
Which number identifies the system that serves as the site of nutrient and waste exchange between cells and the interstitial fluid?
2
Which number identifies the system that serves as the source of all blood cells?
5
Which organelle contains structures that bind to docking-marker acceptors?
5
Which organelle gives rise to specialized vesicles that contain hydrolytic enzymes?
2
Which organelle uses oxygen to strip hydrogens from organic molecules?
2
Which protein could be associated with active movement of a substance through the membrane?
2
Which protein could represent the GLUT protein in the membrane of an intestinal cell?
2
Which protein might be an ATPase?
2
Which protein might require ATP in order to transport a particle through the membrane?
d
Which step will come immediately after the carrier releases the ions shown in this figure? a. The carrier will become phosphorylated. b. The carrier will pick up ions from the ECF. c. The carrier will pick up ions from the ICF. d. The carrier will split ATP. e. The carrier will become phosphorylated and The carrier will split ATP.
Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if both presynaptic neurons A and B were fired simultaneously?
b
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for Na+ at the end of an action potential
b
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for Na+ at threshold potential
b
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Electrical gradient for Na+ at threshold potential
b
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Na+ concentration in the neuron's cytosol immediately before an action potential B. Na+ concentration in the neuron's cytosol immediately following an action potential
b
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Neuron's permeability to Na+ during the falling phase of an action potential B. Neuron's permeability to K+ during the falling phase of an action potential
b
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting membrane potential B. Potential during hyperpolarization
b
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to K+ B. Neuron's permeability to K+ during the falling phase of an action potential
b
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to Na+ B. Neuron's permeability to Na+ during the rising phase of an action potential
b
Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PCl- of the subsynaptic membrane
b
Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PK+ of the subsynaptic membrane (no change in PNa+)
b
Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Small hyperpolarization of the postsynaptic neuron
b
Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During an EPSP
b
Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During the rising phase of an action potential
b
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Large: 2 to 40 amino acids in length
b
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Usually function as neuromodulators
b
Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Prevents release of GABA
b
The structure labeled "4" is a. part of a channel that allows Na+ ions to diffuse into the ECF b. the activation gate for a gated K+ channel c. the inactivation gate for a gated Na+ channel d. part of a second messenger system e. the activation gate for a gated K+ channel and part of a second messenger system
b
This figure shows a. the mechanism by which some lipid-soluble hormones affect their target cells b. the way insulin affects certain cells c. the method in which IP3 forms d. a common second messenger system for hormone that is derived from cholesterol e. none of these
b
Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if presynaptic neuron B were fired rapidly?
c
Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Dendrite
c
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Released from axon terminal
c
Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Competes with glycine for receptors
c
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Permeability changes at the start of an IPSP
c
Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During the falling phase of an action potential
a
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Small: one amino acid or similar chemical
a
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Synthesized in cytosol of synaptic knob
a
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Usually open specific ion channels
a
Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Destroys myelin
a
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Permeability changes at threshold voltage
a
Which number identifies the structure that is primarily responsible for the absolute refractory period during an action potential? a. 1 b. 2 c. 3 d. 4 e. None of the above
a
Sequence the following events correctly. 1. Neurotransmitter diffuses across cleft. 2. Calcium induces exocytosis of neurotransmitter. 3. Permeability of postsynaptic membrane altered. 4. Ion channels open. 5. Neurotransmitter binds to receptor.
a. 1, 2, 3, 5, 4 b. 1, 4, 3, 2, 5 c. 2, 1, 5, 4, 3 d. 3, 1, 4, 5, 2 e. 5, 4, 3, 1, 2 ANS: C PTS: 1 DIF: Comprehension
b
a. could eventually have the same number of red solute particles as the solution on the left side of the membrane b. could eventually have the same concentration of red particles as the solution on the left side of the membrane c. currently has a higher osmotic pressure than the solution on the left side of the membrane d. is currently gaining water e. all of these
A second messenger is labeled a. 1 b. 2 c. 3 d. 4 e. 5
d
Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Axon
d
Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a. neurotransmitters b. neuropeptides c. both neurotransmitters and neuropeptides d. neither neurotransmitters nor neuropeptides Released into blood for delivery to target
d
Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease May predispose a person to multiple sclerosis
d
Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Synapse
e
Label "3" is a. a second messenger b. a kinase protein c. a G protein d. a G protein coupled receptor e. an effector enzyme
e
Match neural disease/influence with correct characteristic. a. multiple sclerosis b. tetanus c. strychnine d. roseola e. Parkinson's disease Due to insufficient dopamine
e
The structure labeled "1" is a. part of a chemically-gated channel b. part of a mechanically-gated channel c. the activation gate of a Na+ channel d. part of a chemically-gated channel and the inactivation gate of a Na+ channel e. none of these
e
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Permeability changes that occur at the peak of an action potential
e
Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Acetylcholine
f
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement responsible for the rising phase of the action potential
f
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement that would cause an EPSP
f
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement responsible for the falling phase of the action potential
h
Use the answer code below to answer this section. a. increased PNa+ and no change in PK+ b. decreased PNa+ and decreased PK+ c. increased PK+ and no change in PNa+ d. increased PK+ and increased PNa+ e. increased PK+ and decreased PNa+ f. Na influx g. Na+ efflux h. K+ influx i. K+ efflux Ion movement that would cause an IPSP
i
Neuron A is excitatory to neuron B. Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.
(1) Neuron A is not stimulated; therefore, it will not generate EPSPs on neuron B. (2) Neuron A is actively inhibited by the formation of IPSPs on its dendrites and cell body; therefore, action potentials are not generated at A's axon hillock. (3) Neuron A sends an impulse along its axon, but another neuron inhibits the release of neurotransmitter from A's axon terminal; this is presynaptic inhibition and no EPSPs are generated on B. PTS: 1 DIF: Evaluation
e
In beaker 1, the solution on the right side of the membrane a. could eventually have the same concentration of green solute particles as the solution on the left side of the membrane b. could eventually have the same osmolarity as the solution on the left side of the membrane c. currently has a lower osmotic pressure than the solution on the left side of the membrane d. is currently losing water e. all of these
a
In beaker 1, the solution on the right side of the membrane a. has a lower osmolarity than the solution on the left side of the membrane b. will gain water from the solution on the left side of the membrane c. has a higher osmotic pressure than the solution on the left side of the membrane d. has a lower osmolarity than the solution on the left side of the membrane and will gain water from the solution on the left side of the membrane e. will gain water from the solution on the left side of the membrane and has a higher osmotic pressure than the solution on the left side of the membrane
b
In this figure, the carrier is a. transporting Na+ ions into the ECF b. transporting K+ ions into the ICF c. about to become phosphorylated. d. performing secondary active transport e. transporting K+ ions into the ICF and performing secondary active transport
Describe the various functions of proteins in membranes.
The different types of proteins in the plasma membrane may function as the following: (a) channels that allow the movement of specific ions or polar molecules down a concentration gradient; (b) carriers, which change shape to transport substances either down or up a concentration gradient; (c) docking-marker acceptors, which bind to secretory vesicles and trigger exocytosis; (d) membrane-bound enzymes that facilitate specific chemical reactions; (e) receptors, which bind to chemical messengers in the ECF and can then trigger reactions inside the cell; (e) cell adhesion molecules (CAMs) that can help hold adjacent cells together; and (f) cell-recognition markers that allow the body to recognize its own cells. PTS: 1 DIF: Comprehension
Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ During an IPSP
a
Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place. a. no change in potential of the postsynaptic cell b. spatial summation c. temporal summation What would occur if both presynaptic neurons A and C were fired simultaneously?
a
Choose the match for each substance listed. a. covering on the axon b. second messenger c. branching process from a cell body d. impulse-conducting region e. junction between neurons f. neurotransmitter Myelin
a
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for K+ at the end of an action potential
a
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Concentration gradient for K+ at the peak of an action potential
a
Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: a. tends to move the involved ion out of the cell b. tends to move the involved ion into the cell Electrical gradient for K+ at the peak of an action potential
a
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. K+ concentration in the neuron's cytosol immediately before an action potential B. K+ concentration in the neuron's cytosol immediately following an action potential
a
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Na+ concentration in the extracellular fluid B. Na+ concentration in the neuron's cytosol immediately following an action potential
a
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Neuron's permeability to Na+ during the rising phase of an action potential B. Neuron's permeability to K+ during the rising phase of an action potential
a
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting membrane potential B. Potential during depolarization
a
Indicate the relationship between the two items listed in each situation: a. A is greater than B. b. B is greater than A. c. A and B are equal. A. Resting neuron's permeability to K+ B. Resting neuron's permeability to Na+
a
Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Increased PNa+ and increased PK+ of the subsynaptic membrane
a
Indicate whether an excitatory or inhibitory synapse is being described. a. excitatory synapse b. inhibitory synapse Small depolarization of the postsynaptic neuron
a
Indicate whether the membrane is more permeable to K+ or to Na+ or is equally permeable to these ions under the stated conditions: a. more permeable to K+ than to Na+ b. more permeable to Na+ than to K+ c. equally permeable to Na+ and K+ At resting potential
a