SFSU BIOL 212 Final Exam Actual Exam Newest Actual Exam With Complete 100
Questions And Correct Detailed Answers (Verified Answers) |Already Graded A+
Question 1
Homeostasis refers to the maintenance of a relatively stable internal environment. Which of the
following specifically constitutes the "internal environment" of the human body?
A) The cytoplasm within all cells
B) The intracellular fluid (ICF)
C) Plasma, interstitial fluid, and transcellular fluid
D) The internal organs located beneath the skin
E) The blood cells themselves
Correct Answer: C) plasma, interstitial fluid, and transcellular fluid
Rationale: In physiology, the "internal environment" refers specifically to the Extracellular
Fluid (ECF). This is the fluid that surrounds the cells and serves as the interface between
the cells and the external world. The ECF is comprised of three sub-compartments: plasma
(the liquid portion of blood), interstitial fluid (fluid in the spaces between cells), and
transcellular fluid (specialized fluids like cerebrospinal or synovial fluid). Maintaining the
stability of this fluid is the primary goal of homeostatic mechanisms.
Question 2
Which of the following scenarios best illustrates the concept of a positive feedback loop?
A) An increase in blood pressure triggers a decrease in heart rate to return pressure to baseline.
B) Consuming caffeine increases urine output, leading to a state of dehydration.
C) The arrival of platelets at a wound site causes the release of clotting factors, which in turn
attracts even more platelets to the site.
D) Sweating in response to high ambient temperatures to lower core body temperature.
E) The release of insulin in response to high blood glucose levels.
Correct Answer: C) The arrival of platelets at a wound causes the release of clotting factors
which cause more platelets to arrive at the wound
Rationale: Positive feedback loops are characterized by a response that reinforces or
amplifies the initial stimulus, moving the system further away from the starting point. In
blood clotting, the initial presence of platelets triggers a cascade that recruits more platelets
until the wound is sealed. This is distinct from negative feedback (like blood pressure or
, 2
temperature regulation), which acts to reverse the stimulus and return the body to a set
point.
Question 3
Following a significant increase in core body temperature, the body initiates several
thermoregulatory responses. Which of the following will NOT occur?
A) An increase in skin blood flow via vasodilation
B) An increase in sweat production by eccrine glands
C) An increase in non-shivering thermogenesis
D) An increase in the temperature of the skin
E) An increase in evaporation from the skin surface
Correct Answer: C) an increase in non-shivering thermogenesis
Rationale: Non-shivering thermogenesis is a heat-generating process, primarily occurring in
brown adipose tissue, used to increase body temperature when an individual is cold. If the
body is already experiencing an increase in temperature, it will prioritize heat-loss
mechanisms (like vasodilation and sweating) and will specifically inhibit heat-generating
processes like shivering or non-shivering thermogenesis.
Question 4
True or False: When pyrogens are present in the body, the hypothalamus resets the body’s
"thermostat" to a higher level, and vasodilation is then used to create a fever.
A) True
B) False
Correct Answer: B) False
Rationale: While the statement about pyrogens resetting the thermostat is true, the method
used to reach that higher temperature is not vasodilation. To create a fever (heat up), the
body uses vasoconstriction to prevent heat loss and shivering to generate heat. Vasodilation
is a cooling mechanism used when the fever "breaks" and the body needs to return to its
normal set point.
Question 5
A specific lab strain of mice remains healthy only if fed regularly and kept sedentary. If they fast
, 3
or exercise, their blood glucose drops to dangerous levels. However, after a meal, their glucose
returns to a stable level. Which of the following is the most likely hypothesis for this condition?
A) The mice have Type 1 (insulin-dependent) diabetes.
B) The mice lack functional insulin receptors on their target cells.
C) The mice lack functional glucagon receptors on their liver cells.
D) The mice are unable to synthesize glycogen from glucose.
E) The mice have an overactive sodium-potassium pump.
Correct Answer: C) the mice lack glucagon receptors on their cells
Rationale: Glucagon is the hormone responsible for raising blood glucose during periods of
fasting or high energy demand (exercise) by stimulating the liver to break down glycogen
(glycogenolysis). If the mice have normal insulin function (evidenced by the rise and
subsequent homeostatic decline after eating) but cannot maintain levels during fasting, the
failure likely lies in the glucagon signaling pathway.
Question 6
In the regulation of blood glucose, liver cells (hepatocytes) are stimulated to produce and store
glycogen in response to which hormone?
A) Glucagon
B) Epinephrine
C) Cortisol
D) Insulin
E) Aldosterone
Correct Answer: D) insulin
Rationale: Insulin is the "hormone of plenty," released by the pancreas when blood glucose
levels are high. It promotes glycogenesis (the synthesis of glycogen from glucose) in the liver
and skeletal muscles. This effectively lowers blood glucose by moving the sugar into
storage. Glucagon does the opposite, triggering the breakdown of glycogen.
Question 7
Which of the following describes a primary mechanism of action for insulin in regulating cellular
glucose uptake?
, 4
A) Activating the primary Na+/K+ ATPase pump
B) Increasing the activity of SGLT (sodium-glucose linked transporters)
C) Increasing the facilitated diffusion of glucose by inserting more GLUT carriers into the cell
membrane
D) Decreasing the permeability of the cell to potassium
E) Stimulating the production of cAMP via G-proteins
Correct Answer: C) increase the facilitated diffusion of glucose into certain cells in the body
Rationale: Insulin binds to its receptor (a tyrosine kinase receptor), which triggers a signal
transduction cascade. This results in the translocation of GLUT4 transporters from
intracellular vesicles to the plasma membrane. This increase in the number of carriers
allows glucose to enter the cell more rapidly via facilitated diffusion.
Question 8
In cellular respiration, NADH is a critical electron carrier. NADH is produced during all of the
following stages EXCEPT:
A) Aerobic Glycolysis
B) The Citric Acid (Krebs) Cycle
C) The Electron Transport Chain
D) The conversion of Pyruvate to Acetyl CoA
E) The oxidation of Isocitrate
Correct Answer: B) during the electron transport chain
Rationale: NADH is a product of the oxidative stages of metabolism: Glycolysis, the
Intermediate Step (Pyruvate to Acetyl CoA), and the Krebs Cycle. However, in the Electron
Transport Chain (ETC), NADH is a reactant (a "donor"). It unloads its electrons at
Complex I and is oxidized back into NAD+. Therefore, the ETC consumes NADH rather
than producing it.
Question 9
Under anaerobic conditions (low oxygen), which molecule must unload its electrons (be
oxidized) to ensure that the NAD+ pool is replenished so that glycolysis can continue to produce
ATP?
Questions And Correct Detailed Answers (Verified Answers) |Already Graded A+
Question 1
Homeostasis refers to the maintenance of a relatively stable internal environment. Which of the
following specifically constitutes the "internal environment" of the human body?
A) The cytoplasm within all cells
B) The intracellular fluid (ICF)
C) Plasma, interstitial fluid, and transcellular fluid
D) The internal organs located beneath the skin
E) The blood cells themselves
Correct Answer: C) plasma, interstitial fluid, and transcellular fluid
Rationale: In physiology, the "internal environment" refers specifically to the Extracellular
Fluid (ECF). This is the fluid that surrounds the cells and serves as the interface between
the cells and the external world. The ECF is comprised of three sub-compartments: plasma
(the liquid portion of blood), interstitial fluid (fluid in the spaces between cells), and
transcellular fluid (specialized fluids like cerebrospinal or synovial fluid). Maintaining the
stability of this fluid is the primary goal of homeostatic mechanisms.
Question 2
Which of the following scenarios best illustrates the concept of a positive feedback loop?
A) An increase in blood pressure triggers a decrease in heart rate to return pressure to baseline.
B) Consuming caffeine increases urine output, leading to a state of dehydration.
C) The arrival of platelets at a wound site causes the release of clotting factors, which in turn
attracts even more platelets to the site.
D) Sweating in response to high ambient temperatures to lower core body temperature.
E) The release of insulin in response to high blood glucose levels.
Correct Answer: C) The arrival of platelets at a wound causes the release of clotting factors
which cause more platelets to arrive at the wound
Rationale: Positive feedback loops are characterized by a response that reinforces or
amplifies the initial stimulus, moving the system further away from the starting point. In
blood clotting, the initial presence of platelets triggers a cascade that recruits more platelets
until the wound is sealed. This is distinct from negative feedback (like blood pressure or
, 2
temperature regulation), which acts to reverse the stimulus and return the body to a set
point.
Question 3
Following a significant increase in core body temperature, the body initiates several
thermoregulatory responses. Which of the following will NOT occur?
A) An increase in skin blood flow via vasodilation
B) An increase in sweat production by eccrine glands
C) An increase in non-shivering thermogenesis
D) An increase in the temperature of the skin
E) An increase in evaporation from the skin surface
Correct Answer: C) an increase in non-shivering thermogenesis
Rationale: Non-shivering thermogenesis is a heat-generating process, primarily occurring in
brown adipose tissue, used to increase body temperature when an individual is cold. If the
body is already experiencing an increase in temperature, it will prioritize heat-loss
mechanisms (like vasodilation and sweating) and will specifically inhibit heat-generating
processes like shivering or non-shivering thermogenesis.
Question 4
True or False: When pyrogens are present in the body, the hypothalamus resets the body’s
"thermostat" to a higher level, and vasodilation is then used to create a fever.
A) True
B) False
Correct Answer: B) False
Rationale: While the statement about pyrogens resetting the thermostat is true, the method
used to reach that higher temperature is not vasodilation. To create a fever (heat up), the
body uses vasoconstriction to prevent heat loss and shivering to generate heat. Vasodilation
is a cooling mechanism used when the fever "breaks" and the body needs to return to its
normal set point.
Question 5
A specific lab strain of mice remains healthy only if fed regularly and kept sedentary. If they fast
, 3
or exercise, their blood glucose drops to dangerous levels. However, after a meal, their glucose
returns to a stable level. Which of the following is the most likely hypothesis for this condition?
A) The mice have Type 1 (insulin-dependent) diabetes.
B) The mice lack functional insulin receptors on their target cells.
C) The mice lack functional glucagon receptors on their liver cells.
D) The mice are unable to synthesize glycogen from glucose.
E) The mice have an overactive sodium-potassium pump.
Correct Answer: C) the mice lack glucagon receptors on their cells
Rationale: Glucagon is the hormone responsible for raising blood glucose during periods of
fasting or high energy demand (exercise) by stimulating the liver to break down glycogen
(glycogenolysis). If the mice have normal insulin function (evidenced by the rise and
subsequent homeostatic decline after eating) but cannot maintain levels during fasting, the
failure likely lies in the glucagon signaling pathway.
Question 6
In the regulation of blood glucose, liver cells (hepatocytes) are stimulated to produce and store
glycogen in response to which hormone?
A) Glucagon
B) Epinephrine
C) Cortisol
D) Insulin
E) Aldosterone
Correct Answer: D) insulin
Rationale: Insulin is the "hormone of plenty," released by the pancreas when blood glucose
levels are high. It promotes glycogenesis (the synthesis of glycogen from glucose) in the liver
and skeletal muscles. This effectively lowers blood glucose by moving the sugar into
storage. Glucagon does the opposite, triggering the breakdown of glycogen.
Question 7
Which of the following describes a primary mechanism of action for insulin in regulating cellular
glucose uptake?
, 4
A) Activating the primary Na+/K+ ATPase pump
B) Increasing the activity of SGLT (sodium-glucose linked transporters)
C) Increasing the facilitated diffusion of glucose by inserting more GLUT carriers into the cell
membrane
D) Decreasing the permeability of the cell to potassium
E) Stimulating the production of cAMP via G-proteins
Correct Answer: C) increase the facilitated diffusion of glucose into certain cells in the body
Rationale: Insulin binds to its receptor (a tyrosine kinase receptor), which triggers a signal
transduction cascade. This results in the translocation of GLUT4 transporters from
intracellular vesicles to the plasma membrane. This increase in the number of carriers
allows glucose to enter the cell more rapidly via facilitated diffusion.
Question 8
In cellular respiration, NADH is a critical electron carrier. NADH is produced during all of the
following stages EXCEPT:
A) Aerobic Glycolysis
B) The Citric Acid (Krebs) Cycle
C) The Electron Transport Chain
D) The conversion of Pyruvate to Acetyl CoA
E) The oxidation of Isocitrate
Correct Answer: B) during the electron transport chain
Rationale: NADH is a product of the oxidative stages of metabolism: Glycolysis, the
Intermediate Step (Pyruvate to Acetyl CoA), and the Krebs Cycle. However, in the Electron
Transport Chain (ETC), NADH is a reactant (a "donor"). It unloads its electrons at
Complex I and is oxidized back into NAD+. Therefore, the ETC consumes NADH rather
than producing it.
Question 9
Under anaerobic conditions (low oxygen), which molecule must unload its electrons (be
oxidized) to ensure that the NAD+ pool is replenished so that glycolysis can continue to produce
ATP?
