Biology 2 Final Exam
UCF with 100% correct
answers ( graded A+)
What are dendrites? - answer Numerous branched extensions
from cell body that receive signals from other neurons
What are axons? - answer Single, longer extension transmits
signals to neurons or effector cells
Where are axon potentials initiated? - answer Axon hillock
What are glia cells? - answer Supporting cells that nourish
neurons, insulate axons of neurons
At rest, are neurons positively charged or negatively charged? -
answer Negatively charged
What are graded potentials? - answer hyperpolarization or
depolarization of excitable cells that does not lead to an action
potential
What is EPSP? - answer A permeable to both K+ and Na+.
Depolarization brings the membrane potential toward threshold
,What is IPSP? - answer Permeable to K+ or Cl-. Moves membrane
potential further from threshold
What is the sodium-potassium pump? - answer an active transport
mechanism in the plasma membrane that:
1) transports sodium and potassium ions in opposite directions
and
2) at different rates
~ maintains a ratio of 3 Na+/ 2 K+
- for every 100K+ inside, 150Na+ outside
- Therefore, it is more positive outside and less positive (more
negative) inside.
What is the process of hyperpolarization? - answer Opening of K+
channels, K+ leaves the cell membrane and increases the
negative charge inside the neuron.
What is the process of depolarization? - answer Opening ion
channels, e.g. gated sodium channels, which enter the cell
making inside of membrane less negative
What are the steps of an action potential? - answer 1. Resting
state: Gated K+ and Na+ channels closed. Ungated channels still
open.
2. Depolarization: some Na+ channels open
, 3. If reaches threshold = action potential is triggered. Many Na+
open. Neuron is positive.
4. Na+ channels close, K+ opens. Restores negativity.
5. Undershoot: Membrane permeability to K+ temporarily higher
than at rest
6. Resting membrane potential.
Where are Schwann cells found? - answer PNS
Describe the Nernst equilibrium. - answer The Nernst equilibrium
is the point at which the concentration gradient of an ion is equal
to the opposite electrostatic gradient
T or F: [Na+] is higher inside the cell at resting potential - answer
False, [Na+] is higher outside the cell and [K+] is higher inside
the cell.
Neurotransmitters diffuse across - answer Synaptic cleft
T or F: Bilateral organisms have more specialized nervous
systems. - answer True
What is the function of motor cortex's - answer It sends
commands to skeletal muscles
What is the input center of sensory information to the cerebrum -
answer Thalamus
UCF with 100% correct
answers ( graded A+)
What are dendrites? - answer Numerous branched extensions
from cell body that receive signals from other neurons
What are axons? - answer Single, longer extension transmits
signals to neurons or effector cells
Where are axon potentials initiated? - answer Axon hillock
What are glia cells? - answer Supporting cells that nourish
neurons, insulate axons of neurons
At rest, are neurons positively charged or negatively charged? -
answer Negatively charged
What are graded potentials? - answer hyperpolarization or
depolarization of excitable cells that does not lead to an action
potential
What is EPSP? - answer A permeable to both K+ and Na+.
Depolarization brings the membrane potential toward threshold
,What is IPSP? - answer Permeable to K+ or Cl-. Moves membrane
potential further from threshold
What is the sodium-potassium pump? - answer an active transport
mechanism in the plasma membrane that:
1) transports sodium and potassium ions in opposite directions
and
2) at different rates
~ maintains a ratio of 3 Na+/ 2 K+
- for every 100K+ inside, 150Na+ outside
- Therefore, it is more positive outside and less positive (more
negative) inside.
What is the process of hyperpolarization? - answer Opening of K+
channels, K+ leaves the cell membrane and increases the
negative charge inside the neuron.
What is the process of depolarization? - answer Opening ion
channels, e.g. gated sodium channels, which enter the cell
making inside of membrane less negative
What are the steps of an action potential? - answer 1. Resting
state: Gated K+ and Na+ channels closed. Ungated channels still
open.
2. Depolarization: some Na+ channels open
, 3. If reaches threshold = action potential is triggered. Many Na+
open. Neuron is positive.
4. Na+ channels close, K+ opens. Restores negativity.
5. Undershoot: Membrane permeability to K+ temporarily higher
than at rest
6. Resting membrane potential.
Where are Schwann cells found? - answer PNS
Describe the Nernst equilibrium. - answer The Nernst equilibrium
is the point at which the concentration gradient of an ion is equal
to the opposite electrostatic gradient
T or F: [Na+] is higher inside the cell at resting potential - answer
False, [Na+] is higher outside the cell and [K+] is higher inside
the cell.
Neurotransmitters diffuse across - answer Synaptic cleft
T or F: Bilateral organisms have more specialized nervous
systems. - answer True
What is the function of motor cortex's - answer It sends
commands to skeletal muscles
What is the input center of sensory information to the cerebrum -
answer Thalamus
