<p>lol those are amazing. Thank u thank u thank u</p>
<p>HELP ME WITH HYPERTONIC HYPOTONIC… I know they go from high to low. I also know that hypertonic has a higher concentration of solutes, but then what does this mean?</p>
<p>Cliff’s review book 2nd edition page 227??!?!?!?!
Fresh water fish. The body of a fresh water fish is hyperosmotic, or saltier than the surrounding water. Thus water constantly diffuses into the fish.</p>
<p>is it based on the water?</p>
<p>Hypertonic = more solvent than solute (more salt in the body than water in the fishy’s case)
Hypotonic = less solven than solute (less salt in the body than water in another fishy’s case)
osmotic just means it’s dealing with water.
Basically, freshwater fish are hyperosmotic because the water surrounding them is less salty than their insides. Water diffuses across said concentration gradient passively (via osmosis - get it?). Marine fish have less salt than in the ocean (ocean’s pretty salty!) so they are considered HYPOosmotic. Hyper/hypotonic are used to describe how much of a substance is dissolved in another substance (how much solute in a solvent) qualitatively.</p>
<p>cliffs p. 149. like 100 more pages to go…not to mention i wanna read it a second time and do the 2 practice tests. ■■■</p>
<p>@Topangaa: It’s the same thing as being hypertonic: the fish has a greater concentration of solutes (salt) in their body, thus water diffuses into the fish. Because of this, the fish excrete often, and drink very little. They also secrete some salt through glands (which I believe are in their gills… but I’m not sure). </p>
<p>The tonicity (hyper or hypo) refers to the concentration of solutes. Higher concentration of solutes = hypertonic; lower = hypotonic. </p>
<p>Also remember, water follows the solutes. </p>
<p>Saltwater fish are HYPOosmotic to the salt water, meaning they have less solute (salt) in their body. Therefore, water is always diffusing OUT of the fish, meaning they must drink a lot.</p>
<p>anyone not feeling so optimistic about this exam? i feel amazingly prepared for econ, but i have this feeling of impending doom and destruction about this exam =S</p>
<p>lower the curve for us ^^?</p>
<p>What occurs in neurons during the refractory period following an action potential?
A. ATP is regenerated from ADP + Pi.
B. Na+ moves across the neuron membrane from outside to inside.
C. K+ moves across the neuron membrane from inside to outside.
D. Na+ on the inside and K+ on the outside exchange places across the neuronmembrane
E. The outside of the membrane becomes more negative with respect to the inside.</p>
<p>have they ever asked about operons in Free response?..</p>
<p>My teacher gave my class some awesome links to AP Bio reviews on youtube: [YouTube</a> - bozemanbiology’s Channel](<a href=“http://www.youtube.com/user/bozemanbiology]YouTube”>http://www.youtube.com/user/bozemanbiology)</p>
<p>I don’t know if that’s already been suggested, but here ya go anyway.</p>
<p>I’m hugely freaked out right now. I think I’m physically incapable of studying. I didn’t have school at all last week (flooding), but I didn’t start studying until yesterday. I still have to review ALL the labs, photosynthesis, the animal form and function chapter, and the animal reproduction chapters in Cliffs. Also, I will die.</p>
<p>i believe it is E?</p>
<p>I’m pretty sure it’s D. It can’t be E because in the refractory period, polarization is reduced.</p>
<p>yeah i think your right… but if they switch places like that, wouldn’t the outside membrane be more negative? </p>
<p>god im getting to overthinkin these questions…</p>
<p>D. The Na+/K+ protein pumps in the membranes of neurons exchange Na+ and K+ so that their concentrations on each side of the membrane return to resting potential concentrations.</p>
<p>It’s still polarized, but just backwards, with K+ on the outside and Na+ on the inside. Reversing places restores the original distribution of the ions and returns them to their resting potential.</p>
<p>yup exactly what i was thinking… cept i overthought…</p>
<ol>
<li>Systolic blood pressure is maintained by the
A. left atrium
B. right atrium
C. left ventricle
D. right ventricle
E. semilunar valves in the aorta</li>
</ol>
<p>C
im pretty sure…
god i hate these pressures.</p>
<p>and did you get release of 08?^ i neeeed</p>
<p>Here’s one for you, Years:</p>
<p>If only K+ gates open on the postsynaptic membrane, then:
a) the postsynaptic membrane releases a neurotransmitter
b) an excitatory postsynaptic potential (EPSP) is established
c) the postsynaptic neuron is stimulated
d) the postsynaptic neuron is inhibited
e) Ca2+ is released</p>
<p>It is C. Oh and they guy never pm’d me back :(</p>