Question 1
Inhibitory postsynaptic potentials (IPSPs)
◦ increase membrane permeability to sodium ions.
◦ result in depolarizations.
◦ result in hyperpolarizations.
◦ decrease potassium ion exit from cells.
◦ decrease calcium ion exit from cells.
Question 2
When two or more graded potentials arrive at the trigger zone, which of the following could happen?
◦ Two inhibitory stimuli may be additive, resulting in lower excitability.
◦ An excitatory and inhibitory signal can cancel each other out and two excitatory stimuli may be additive, and summation could occur.
◦ An excitatory and inhibitory signal can cancel each other out.
◦ Two excitatory stimuli may be additive, and summation could occur.
◦ An excitatory and inhibitory signal can cancel each other out; two excitatory stimuli may be additive, and summation could occur; and two inhibitory stimuli may be additive, resulting in lower excitability.
Distributions of two barnacle species within the intertidal zone
Decremental property of graded potentials.
Comparison of Graded Potentials and Action Potentials
Aggregates are people who happen to be in the same place at the same time.
A typical intertidal zone
Twilight Zone