1
Expert solutions
Bio 2301 Exam Review Questions and Answers
(100% Correct Answers) Already Graded A+
Homeostasic
✓✓ Dynamic process that enables the body to maintain "balanced" conditions
internally in the face of external changes.
Positive feedback. Example?
✓✓ The body's reaction to a variable, in the same direction. Blood clotting is an
example.
Negative feedback. Example?
✓✓ The body's reaction to a variable, in the opposite direction. Temperature gets
to hot, body sweats to cool back down.
Which is most common, positive or negative feedback?
✓✓ Negative
What factors influence the rate of diffusion?
✓✓ Substance-Lipid soluble cells diffuse easier than water soluble. Molecular
charge.
How does active transport differ from passive transport?
✓✓ Active transport requires ATP while Passive transport uses random kinetic
energy.
What are the two types of active transport?
✓✓ Active and Endo/Exocytosis
What conditions create resting membrane potential (RMP) ?
✓✓ K+ ions are leaving the cell causing the inside to be negative. Na+ ions are
entering the cell.
, 2
Expert solutions
Which ions are greater in concentration outside of the cell?
✓✓ Na+ (sodium)
Which ions are greater in concentration inside of the cell?
✓✓ K+ (potassium)
What is Depolarization?
✓✓ When the potential is less negative/more positive than the resting level of -
70mV (from -70mV towards +30mV)
What is Repolarization?
✓✓ When a membrane potential has been depolarized and is now returning
towards it's resting value. (From +30mV to -70mV) or becomes more
negative/less positive.
What is Hyperpolarization?
✓✓ When the potential is more negative than the resting level (below -70mV)
Understand all events that occur during an action potential.
✓✓ 4 Steps.
Step 1 of Action Potential (RMP)
✓✓ Sodium and potassium channels are closed. Na+ rush into the cell; K+ are
concentrated inside the cell.
Step 2 of Action Potential (Depolarization)
✓✓ Sodium channels open in response to a stimulus. Na+ rush into the cell
according to the dictates of diffusion. Final potential difference +30 mV.
Step 3 of Action Potential (Repolarization)
✓✓ Na+ channels close and K+ channels open. K+ rush out of the cell
according to the dictates of diffusion.
Step 4 of Action Potential (Resting conditions re established)
Expert solutions
Bio 2301 Exam Review Questions and Answers
(100% Correct Answers) Already Graded A+
Homeostasic
✓✓ Dynamic process that enables the body to maintain "balanced" conditions
internally in the face of external changes.
Positive feedback. Example?
✓✓ The body's reaction to a variable, in the same direction. Blood clotting is an
example.
Negative feedback. Example?
✓✓ The body's reaction to a variable, in the opposite direction. Temperature gets
to hot, body sweats to cool back down.
Which is most common, positive or negative feedback?
✓✓ Negative
What factors influence the rate of diffusion?
✓✓ Substance-Lipid soluble cells diffuse easier than water soluble. Molecular
charge.
How does active transport differ from passive transport?
✓✓ Active transport requires ATP while Passive transport uses random kinetic
energy.
What are the two types of active transport?
✓✓ Active and Endo/Exocytosis
What conditions create resting membrane potential (RMP) ?
✓✓ K+ ions are leaving the cell causing the inside to be negative. Na+ ions are
entering the cell.
, 2
Expert solutions
Which ions are greater in concentration outside of the cell?
✓✓ Na+ (sodium)
Which ions are greater in concentration inside of the cell?
✓✓ K+ (potassium)
What is Depolarization?
✓✓ When the potential is less negative/more positive than the resting level of -
70mV (from -70mV towards +30mV)
What is Repolarization?
✓✓ When a membrane potential has been depolarized and is now returning
towards it's resting value. (From +30mV to -70mV) or becomes more
negative/less positive.
What is Hyperpolarization?
✓✓ When the potential is more negative than the resting level (below -70mV)
Understand all events that occur during an action potential.
✓✓ 4 Steps.
Step 1 of Action Potential (RMP)
✓✓ Sodium and potassium channels are closed. Na+ rush into the cell; K+ are
concentrated inside the cell.
Step 2 of Action Potential (Depolarization)
✓✓ Sodium channels open in response to a stimulus. Na+ rush into the cell
according to the dictates of diffusion. Final potential difference +30 mV.
Step 3 of Action Potential (Repolarization)
✓✓ Na+ channels close and K+ channels open. K+ rush out of the cell
according to the dictates of diffusion.
Step 4 of Action Potential (Resting conditions re established)
