Tagged Questions

This tag is for questions about the general biological features of human beings (as opposed to the biology of non-humans).

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What is the most recent well-attested common ancestor of chimpanzees and humans?

Humans and chimpanzees are related and thus have a most recent common ancestor. Of course pinning down this precise point is essentially impossible, so I'm interested in close ancestors of this most ...
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0answers
8 views

Physiological function of CFTR gene product?

I just need a clarification. If I am to talk about the physiological function of the CFTR gene product? Then what should I do research and talk about? The only physiological function that I can ...
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0answers
36 views

Does eating antacid (such as Magnesia) before meal have any impact on digestion?

During an anatomy lecture I heard of the importance of the acidity of gastric acid (e.g., killing microorganisms, dissolving food, being a factor for triggering further processes). If a healthy person ...
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2answers
133 views

The gender of offspring of Twins?

Given identical twin males, Michael and Douglas, Douglas and his wife have four children, all of whom are girls. Michael and his wife have only one child, a boy, and are expecting another. What are ...
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1answer
21 views

Recovery from a more severe injury can be shorter than from a less severe one [on hold]

I vaguely remember reading somewhere that in certain cases, recovery from a more severe injury can occur faster than from a less severe injury. This was motivated by claiming that the less severe ...
7
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1answer
96 views

How fast can a human run?

I'm a runner (cross country) and I'm always amazed at how fast Olympic sprinters are. There's a lot of hype about those in the 100-meter dash being the fastest in the world, and we're constantly ...
3
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1answer
20 views

How is Microenvironment strictly defined?

I started to think this definition of Wikipedia: Microenvironment (biology), a small or relatively small usually distinctly specialized and effectively isolated biophysical environment (as of ...
8
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1answer
64 views

Can a human cell live indefinetely in a controlled environment?

How long can a human cell live in a controlled environment, given all necessary nutrients, temperatures, mechanisms for waste removal, and other requirements are provided for? Put differently: Can a ...
4
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1answer
63 views

Are all functions of a human cell known? [closed]

Please bear with me as I'm intruding into your world from a computer science background. In programming, once you have created a program, you know all functions of that program. Thus, 100% knowledge ...
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1answer
49 views

What causes a polypeptide to fold into an Alpha helix over a Beta pleated sheet

I know how they fold, but what causes some polypeptide chains to preferably fold into Alpha-helix rather than Beta-sheets (or vice-versa). What force makes it fold into one conformation over the ...
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0answers
34 views

birth control pills and eugenics [closed]

The birth control pill is one of the many measures that have been developed to control population. It is arguable that many proponents of eugenics in the years before the pill (1960) would have ...
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0answers
39 views

Regrowing Limbs using MatriStem; Research and Applications

Apparently, there is a substance (powder) called MatriStem which can regrow your nose and the tips of your fingers should they ever become diseased or severed. See here for photos (a bit graphic) ...
3
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1answer
77 views

Do you produce more sperm after 1 week of abstinence vs 1 year of abstinence

Question: I was wondering if the amount of sperm increase with the amount of abstinence? Side questions: Is their a max amount of sperm? What happens with the excess amount?
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1answer
42 views

Is there any research paper which identifies left and right brained behavior?

There are many web puzzle to identify, but does it really have any scientific proof? something like - http://braintest.sommer-sommer.com/en/ any logic behind it?
2
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1answer
44 views

Is the activity of enzymes in the human body affected by the outer temperature?

I have to do a research about the enzymes in the human body and the things that affect them. I know that the body temperature affects the activity of enzyemes but I'd like to know if the outer ...
1
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1answer
17 views

Help me understand my membrane potential assignment

Epithelial with the ability to transport NaCl is bathed in an isotonic salt solution with these values (in mM): 136 Na, 6 K, 140 Cl. The intracellular concentrations are: 45 Na, 100 K, 13 Cl. The ...
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0answers
21 views

Like size and colour constancy, why does the brain not maintain focus constancy?

I have progressive myopia. I grew up with perfectly normal eyes but slowly started getting myopic. The thing is, my brain knows (or should know) what the world looks like -- it knows that far away ...
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2answers
54 views

Can Hepatitis be caused by Bacteria?

There are many information about viral hepatitis. But it is interesting for me, can bacteria cause the hepatitis too?
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1answer
80 views

What are the disadvantages of forbidding flights to and from the African Ebola region?

After looking through the available Stack Exchange sites, this one seems to come closest to the appropriate place to ask... Popular opinion, including my own, is that banning flights to and from the ...
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2answers
45 views

Problems understanding membrane potential

I understand that membrane potential is the difference of the extracellular and intracellular ionic charges, due to their concentrations. We say that the extracellular space has a charge of 0 and then ...
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1answer
28 views

Understanding intra and extracelullar concentrations (membrane potential)

I have 4 question (not homework) What happens to the cells membrane potential if: a) Na+ outside rises by 40mM b) K+ inside rises by 10mM c) K+ outside rises by 10mM d) A- (impermeable ion) ...
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0answers
43 views

Why can you not tickle yourself?

It's the age old question, why can't we tickle ourselves? If you rub your fingers along your skin, sure there's sensation but you don't break down into a laughing fit (at least I don't :P), if someone ...
2
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1answer
34 views

Why can't we smell our own bad breath? [closed]

Why can't we smell our own bad breath. Is there any way we can do that?
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0answers
13 views

Is there a known glucosepane cross-link breaker?

I read the following on wikipedia: There is, however, no agent known that can break down the most common AGE, glucosepane, which appears 10 to 1,000 times more common in human tissue than any ...
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3answers
74 views

Why is it better to drink room temperature water instead of cold water?

My teacher told me that drinking water that is room temperature is better for you then drinking cold water, but she did not tell me why that is. I want to know because I often drink cold water (with ...
2
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0answers
30 views

Are some facial features more important than others in human facial recognition?

I'm often surprised by the human ability to correctly identify other individuals despite significant modifications due to ageing, hairstyle, injury etc. But, sometimes the addition of a beard and a ...
3
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1answer
29 views

How can ingesting a prion “infect” someone?

That's something that's been bugging me for a while... Our gastrointestinal tract produces proteases that degrade proteins. Prions are proteins. Shouldn't they be broken by proteases? Also, how can ...
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0answers
15 views

Can sealed epiphyseal growth plates theoretically be restored via epigenetic or genetic methods?

I know that epiphyseal growth plates seal up once people become young adults and that it is currently impossible to restore them to actively produce new bone growth but, is it theoretically possible ...
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0answers
20 views

Is Canine teeth enough evidence to prove that one is a Carnivore?

This question does not assume that we are meant to be carnivores in the first place; In fact I have no idea to which category we belong to anyway! There are several posts online indicating that ...
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0answers
16 views

Best method to culture lung fibroblasts?

I am just looking for the best method to culture human lung fibroblast from a needle biopsy?
0
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1answer
34 views

Is the innate immune system capable of identifying all foreign antigens?

I've been studying immunology on my own lately and I would like to know if the macrophages and the other components of the innate immune system are capable of identifying all foreign antigens. As far ...
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0answers
26 views

Do animals have social status as humans in our society?

As our society and it's functioning is closely related to the ones of animals, one question arises: Do animals in nature have social status as humans? People often display it publicly, by buying nice ...
3
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1answer
39 views

How does electrolarynx work?

I have heard that this is an effective replacement for patients who have a dysfunctional larynx, partly due to cancer. I am curious to know the inner working of this device and why such a robotic ...
0
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1answer
30 views

Help me understand how the thyroid secretes

Please have a look at this close up light microscopic image of a thyroid gland: So I'm guessing the cubic epithelial cells surrounding this big red pulp are the secreting cells...? If so, is the ...
2
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1answer
68 views

How does an embryo know where to grow limbs etc

For example you have a cell or already a bunch of cells. Those cell(s) divide and after several week you have a grown organism, for example a human with limbs, several different organs etc. However, ...
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0answers
61 views

How many proteins are synthesized in human body throughout life?

My idea to calculate this is: Define up to what age will do the calculation. (for instance 60) Determine how many cells born and died up to that point in life. (by type of cell) Determine how many ...
12
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1answer
68 views

What is the mechanism responsible for the periodicity of hiccups?

Hiccups (singultus) are caused by involuntary spasm of the intercostal muscles and diaphragm, producing a sudden inspiration with associated glottic closure. It seems the neurobiology of the reflex ...
3
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0answers
39 views

Which types of blood vessels can regenerate in humans/mammals?

Which types of blood vessels can regenerate in humans/mammals? From what I understand, arteries and arterioles can be created later in life, while this is not necessarily the case with veins. However ...
8
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1answer
667 views

Does a bigger breast give creamier milk?

It is fairly common for a woman to have one breast larger than the other. I have also heard that, for a breast feeding mother it is common for one of the breasts to yield a creamier milk whilst the ...
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0answers
35 views

Does a pregnant female body treat the fetus based on gender?

I have seen on a youtube video that the female body produces antigenes and antibodies when she is pregnant with a boy. But this behaviour is not produced when she is pregnant with a girl. These means ...
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0answers
21 views

Safety of cobalt-chromium and nickel-chromium dental implants

How safe are cobalt-chromium and nickel-chromium alloys used in dental implants (porcelain fused metal)? IARC groups nickel and cobalt metals in group 2B and chromium in group 3 (hexavalent chromium ...
2
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1answer
47 views

How are arms different than legs?

Ok, this is a bit of a tangent question, but it came up yesterday and I didn't know the answer: How are arms and legs defined physiologically? For example, we say humans have two arms and two legs, ...
3
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1answer
425 views

Do humans have the hyaloid canal, after all?

Most Google Images results for "eye anatomy" are pictures of eyes that don't have the hyaloid canal while some do (proof). Do humans have it, after all, or not? :)
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1answer
775 views

Warm water bath [closed]

Why is it advised to take bath in warm water when we are sick?I know that as homeotherms we need to generate metabolic heat to adapt to the environment temperature.But what is the mechanism by which ...
2
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1answer
41 views

Does Spinning dancer has anything to do with your eyesight

I came across the spinning dancer as part of the brain test to determine left brain vs right brain dominance. I saw the dancer is turning clockwise. The other people around me saw it turning ...
3
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1answer
35 views

Why is Psoriasis treated with Cortisone, when stress (which releases Cortisol) is known to aggravate the condition?

It is well known that stress isn't good for psoriasis , yet why do we treat the illness with Cortisone, a compound very similar to cortisol (and "has a similar name, genesis, and function", according ...
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1answer
31 views

What does it mean to have different “metabolism”?

We hear talk of different body types, and that it is more difficult for certain people to lose weight than others. On the other hand, when my physician recommends that I lose weight, they say that it ...
2
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3answers
67 views

Is the quality of sleep dependent on sleep duration?

I've been facing this lately, where I will wake up in the middle of the night after sleeping for perhaps 2-3 hours and be wide awake, but when I go back to sleep, I wake up more tired than before. ...
12
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1answer
2k views

What do you see when your eyes are closed?

If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still ...
3
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1answer
51 views

Did the Britons 100 years ago have different intestinal flora and fauna?

Note: this is not a question about history, but about human digestive system over time :) I know a lot of colleagues who traveled for business trips to India. All of them caught terrible diarrhea ...