1. What must be true of the concentration of potassium and sodium inside the neuron?
2. Why can some ions move across membranes but others cannot?
3. How would permeability change if types of channels in a neuron change?
4. What is the purpose of having leak and gated channels for the neuron?
5. What are the charges both inside and outside of the neuron before you click
the stimulate neuron button?
6. What are the charges both inside and outside of the neuron after the
simulation is complete?
7. What happens to the charge during the stimulation?
8. What happens after the gated channels close?
9. How many potassium ions move into the cell while how many sodium ions
move out of the cell?
10. What does the yellow line represent that runs along the neuron?

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.

Is genetic diversity the same as genetic variation?