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bio website stackexchange.com
location New York, United States
age 29
visits member for 2 years
seen Jul 21 at 16:02

Student


Feb
11
comment Why does the arch of aorta coils?
@Masi - I'm still confused by "coils." The aorta, as you said, is an elastic artery, and has many layers of smooth muscle and elastic fibers in the tunica media. Don't you mean: "if elasticity is low, then the aorta is stiff"? It requires high elasticity to help maintain a higher diastolic pressure.
Nov
7
comment What difference does it make in the organism's physiology/metabolism whether oxygen binds reversibly or not?
Ignoring the fact that hemocyanin is only in hemolymph and not red blood cells (as in humans), my guess would be no. Hemoglobin exhibits cooperativity, so that the binding of one oxygen molecule increases the affinity for other oxygen molecules. This leads to the sigmoidal oxygen saturation curve, allowing for more efficient dissociation of oxygen at target locations.
Nov
7
comment Preferred Aspect Ratio for Human Eyes
@AlanBoyd I think you're right. For some reason, I was probably thinking about ptosis, when a drooping eyelid does limit your visual field.
Nov
5
comment Preferred Aspect Ratio for Human Eyes
I have to agree with Kal, but mainly about #1. Essentially, the eyes are next to each other, and this allows for stereoscopic vision. If you cover one eye, your field of view is more or less circular (due to the retina and macula), but you'll lose depth perception. Plus, your eyelids slightly limit the amount you can see in the up-down directions.
Oct
3
comment Multi-nucleated cells: advantages and examples?
Technically, all the granulocytes (neutrophils, eosinophils, and basophils) have multiple lobes/segments, not multiple nuclei. Syncytia in cardiac muscle cells is important for coordinated contraction. Not sure about the rest..
Sep
25
comment What is the difference between an antibiotic and an antibacterial?
Just to add to your answer: bacteriostatic agents slow down the growth of bacteria, whereas bactericidal agents kill it.
Aug
29
comment What phenotypes can arise from gender-related aneuploidy?
@Luke Tried to answer some of your questions in the edits. I'm not sure about the cognitive problems though :( I hope someone else can add to it.
Aug
29
comment What phenotypes can arise from gender-related aneuploidy?
I added a little more detail. I'm not sure how 47, XXX individuals are taller, but I can see that the extra Y in 47, XYY individuals make them more masculine. Just a guess though. I'll see if I can find more info about how these disorders cause their cognitive and developmental effects.
Aug
28
comment What kind of fruit is this?
Soda Hall? :P Oh, I remember those days... Anyway, my first thought was also a lychee/litchi. But I thought the fruit is usually whiter and there's usually a seed in the middle..
Aug
23
comment Are there verbs for “undergo mitosis” and “undergo meiosis”?
How about "divide" or even "multiply" (if you include the entire cell cycle)? Those are generic terms, but the process is called cell division. And minor pet peeve of mine: "Google" isn't a verb...
Aug
21
comment Why isn't there any repulsive force between Na+ and K+ disrupting thier roles in transmembrane voltage/ action potentials
I agree with rwst's response below, and just wanted to add that it's not the individual ion species that matter, but the fact that there are several ions, each with ion channels of varying permeabilities. Both sides of the membrane are electrically neutral, but the chemical potentials differ due to the channels. More specifically, the resting membrane potential exists because of the higher permeability of the K+ channels.
Aug
1
comment Is there a biological basis to physical attraction?
@shigeta I agree, and I didn't mean it to sound like attraction was completely biological, just that there is some biological part of it. The examples I chose (or at least the first and last ones) were intended to highlight interesting and bizarre findings that caught my attention. I wrote it at work, so I probably didn't do a good job of writing it up...
Jul
31
comment Does body mass have a bearing on reflex speed?
I didn't take it that way, no worries :)
Jul
30
comment Does body mass have a bearing on reflex speed?
That's really interesting, thanks. I didn't realize there would be such measurable changes, even in the larger nerves. Diabetic neuropathy causes serious problems for people, initially in the hands and feet, due to their distance from the brain. But apparently excess weight can cause negative physiological changes to nerves.
Jul
30
comment Do egg laying animals experience a pregnancy?
And can you also clarify what "pregnancy-like period" refers to? A "period" can refer to two things :P And the short answer is yes, but I don't fully understand the question.
Jul
29
comment How is hibernation/aestivation different from anesthesia?
I'm assuming you're referring to general anesthesia, which still encompasses many types of mechanisms. Here's an interesting article about whether humans can hibernate. It's not a true scientific paper, but it brings up some interesting points.
Jul
27
comment What controls the feeling of discomfort/comfort before and after sleep?
The compound you're thinking about is lactic acid. When oxygen is low, pyruvate is reduced to lactic acid to regenerate NAD+. It might have something to do with the aching related to sleep, but I'm not sure.
Jul
27
comment What negative effects can pinhole glasses have on the body?
Oops, I meant that patching in children can correct amblyopia.
Jul
26
comment What negative effects can pinhole glasses have on the body?
A good reference by someone who studies child vision is here, and a less technical one is here. The infant brain is highly plastic. Completely patching the eye (24/7) will cause form-deprivation myopia, but interestingly, patching a few hours a day (in young children) can correct myopia. But I don't know how pinhole glasses will affect them. And as for studies, well, everything I can find online sounds like a scam.