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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2
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1answer
30 views

Advantage of GCPRs over RTKs or other receptor protein kinases

My book lists two important differences between GCPRs and receptor protein kinases: GCPRs do not directly activate a signal transduction pathway. It only does so indirectly, via a G protein. On the ...
2
votes
0answers
66 views

Can one eye affect the other eye's low-light adaption?

This previous question addresses how long eyes need to adapt to darkness and reach full contrast. My question is how does one eye affect the "transition" and/or efficacy of this "night vision" of the ...
0
votes
1answer
37 views

What is the best way to block cigarette smoke from the body? [closed]

Would it be better to hold your breath after smelling the presence of it or quickly inhale and exhale to get rid of it in your system(body)? EDIT: Changed from carbon monoxide to cigarette smoke.
15
votes
3answers
7k views

Can the dead be brought back to life by viruses?

Zombies have been a part of popular culture for decades. The living dead rising up to take over the world is a terrifying concept, worthy of Hollywood blockbusters and television hits. Some of those ...
3
votes
1answer
102 views

Which literature/study/myth spurred the idea that urine is sterile?

There is a seemingly unfounded mantra that a person's urine is sterile who is not suffering from a UTI. So far I have found convincing evidence to the contrary; urine is not sterile. This poster ...
1
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0answers
14 views

What fills the spaces between non-fused sacral vertebrae?

What is in between the sacral vertebrae before they are fused? I have looked and found no specific descriptions. If it is simply cartilage, what type of cartilage?
2
votes
0answers
40 views

Does medication make the body dependent? [closed]

First of, I know of course that certain medication can cause an addiction if incorrectly used. But as far as I understand it, drugs prone to cause addiction have some agent in it, that makes them ...
2
votes
0answers
28 views

Are there fundamental differences between the adaptive immune systems of higher primates and other mammals?

I recently attended a Leukemia and Lymphoma Society lecture in which one of the lecturers indicated that there are fundamental differences between the adaptive immune systems of higher primates and ...
1
vote
1answer
44 views

What is 'noise'?

In both my psychology, biology and neuroscience classes, professors are constantly talking about 'noise'. For instance, our perception is limited due to 'sensory noise' in our neurons. I am utterly ...
-3
votes
1answer
76 views

Does evolution thinks? [closed]

I understand evolution as survival of the fittest rule , where its the nature and surroundings that shapes the life by extinction of species which are not fit to survive the nature at that period. To ...
2
votes
2answers
71 views

Skull size of Homo naledi

I want to 3D print the skull of the newly discovered Homo naledi. The printing data can be found here: http://morphosource.org/index.php/Detail/MediaDetail/Show/media_id/7300 Where can I find the ...
6
votes
2answers
240 views

At any given moment, how much energy is stored in the human body as ATP?

At any given moment, approximately how much energy is stored in the human body as ATP in the ADP-P-bond? This of course depends on what type of cell it is and the activity of the individual in ...
1
vote
0answers
30 views

Why is exocrinous pancreatic cancer so lethal when compared to others?

I know it seems far fetched, but I would really like to understand why an interference with the regulation of production of pancreatic exocrine products (and which are they) is so lethal. I know that ...
5
votes
1answer
298 views

What is the maximum altitude where humans can survive?

What is the highest altitude that a human can survive without being pressurized? Let's assume that oxygen and heat/insulation are not the limiting factors? Why I asked.
5
votes
1answer
31 views

Constant or variable number of chiasmata during recombination?

During recombination, is the number of chiasmata consistent for each gamete and are the chiasmata regions consistent within a single organism?
1
vote
1answer
160 views

Do human somatic cells have 46 chromosomes all the time?

As far as I know, a human somatic cell has the cell cycle: Interphase and Replication (mitosis). In interphase the cell has 2 growth phases (G1 + G2) and a synthesis one (S phase being in between G1 ...
4
votes
1answer
137 views

Why do we sleep?

While we do know that the human body is regulated by a circadian clock that keeps humans on a sleep/wake cycle, we don’t really know why. Sleep is the time when our bodies repair tissues and perform ...
1
vote
0answers
17 views

Ions in different cell compartments

I would like to understand the distribution of metal ion concentrations (such as Mg2+) in the different cell compartments. I tried very hard but still couldn't find such information. Could anyone ...
4
votes
1answer
227 views

Could a trans-female person ever become pregnant?

I was told that a transgender person, which I will define as anyone assigned male or female at birth that identifies opposite to that assignment, could never become pregnant conceptually, due to the ...
4
votes
1answer
58 views

Are there testosterone receptors in female mammary tissue?

Does female mammary tissue have receptors for testosterone hormones? Do male hormones influence female mammary glands, as female hormones influenced the male mammary tissue, such as in gynecomastia? ...
0
votes
0answers
76 views

Is hypoxia/anoxia the ultimate cause of death?

I know there are different causes of death for humans like heart disease, cancer, stroke, injury and so on, but i was thinking if in every case in the last instance death is due to hypoxia/anoxia. ...
0
votes
1answer
152 views

Why do we have two eyes? [duplicate]

Humans, animals and birds all have two eyes. Why? In addition to why two instead of one, why aren't there more than two?
1
vote
0answers
22 views

is there a difference in meaning between the terms “bone architecture” and “bone structure”?

I'm wondering whether "bone architecture" and "bone structure" mean the same thing, or whether they refer to two different concepts. In this article - ...
6
votes
1answer
76 views

Is eradication of the Common Cold possible?

This is a thought experiment, but everywhere I've read seems to say that colds ALWAYS come from someone else. There's no mention of a cold arising in someone without it coming from another infected ...
0
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0answers
39 views

Life after decapitation? [duplicate]

I saw a video where an ant lost its head and was still walking for some time. If this is possible for an arthropod, what keeps it from working with a vertebrate? (Humans, especially)
1
vote
1answer
60 views

Genotype of children conceived after stem cell transplant?

If you have sickle cell disease and have a succesful stem cell or bone marrow transplant, your blood type changes to AA. But what about your future children? Do your sperm or egg cells continue to ...
0
votes
1answer
47 views

Can skin be removed and replaced so that it maintains its original cellular structure?

The cells in our body that form tissue, such as our skin, are interconnected. I would think that cutting out tissue or trying to repair/replace it, as is done in surgery, or after an injury, could not ...
1
vote
0answers
53 views

Why can't men produce milk, just like women? [duplicate]

This might seem a bit weird, but why can only women produce milk? Wouldn't it be more beneficial to our species if all humans could produce it? I can't think of any reason only one gender would need ...
0
votes
0answers
31 views

Why is alcohol purged from the body more slowly when we sleep?

It is a popular belief that when you get asleep after drinking alcohol, in the morning you have higher level in your blood than if you stayed awake the whole night. Is this true? If so, why? Is it ...
1
vote
1answer
37 views

Who and when was the first human diagnosed with hemophilia, or considered a carrier?

The earliest case I can find is Queen Victoria of England, who ruled from 1837-1901. Is this the first hemophilia case on record?
7
votes
1answer
353 views

What will happen if a foetus is Rh- and the mother is Rh+?

If a mother has Rh-negative blood and her foetus has Rh-positive blood it will result in rhesus incompatibility and lead to erythroblastosis fetalis. What will happen if the reverse occurs, when a ...
2
votes
1answer
40 views

Are all tastes just a combination of sour, sweet, bitter, etc.?

For example, can the taste of pineapple be isolated to just a certain amount of "salty-taste-triggering-molecules" and "sweet-taste-triggering-molecules" etc.? Can our current understanding of the ...
18
votes
2answers
2k views

Can Biologists identify all viruses?

I went to the doctor today with my girlfriend, and the doctor said that she had a virus but doesn't know which one and she should let the infection heal with some rest. The fact that the doctor ...
3
votes
2answers
108 views

Do humans contract more physical sicknesses and diseases than animals do? [duplicate]

I wondered: If I get into the library and look into the medical section it is evident that there are thousands and thousands of different human physical diseases. But if I look into the section of ...
1
vote
1answer
54 views

Breathing becomes harder in certain wind conditions

I'm not sure if this is the right site to ask this, but it seemed like the best option. I've observed on myself that, if I stand on a train platform and a cargo train drives by, creating strong, ...
4
votes
1answer
72 views

Why does a Urinary Tract Infection cause a strong, persistent urge to urinate?

There are plenty of articles on the fact the a urinary tract infection (UTI) causes frequent and urgent urination. For example; on this National Institutes of Health webpage. My question is: Why ...
-2
votes
1answer
190 views

How may the age of a child be estimated when required to do so, in video-graphic evidence?

How may it be possible to roughly conclude that a subject in a select piece of video-graphic evidence presented, is in fact a child, i.e. without the subject being, physically examined? Is it ...
2
votes
1answer
70 views

Reseach on feeling pain of other people

I'm more of a tech than bio kind of guy, but I have read and learned a lot alongside of my girlfriend's education. Which is very interesting!! Currently I want to investigate : people claiming to ...
4
votes
1answer
124 views

Why do you retch when you see something disgusting?

Why do you retch when you see something disgusting? I imagine it is some sort of evolutionary response, although I can't see the connection between receiving a signal that unhealthy conditions are in ...
5
votes
0answers
29 views

Can we predict a person's tolerance to cold exposure during excercise?

Being an amateur athlete and student of anatomy I've always wanted to know if there is a formula for determining an unconditioned body's tolerance to cold temperatures while exercising. I know the ...
1
vote
1answer
79 views

Which part of the reflex arc takes the longest time?

If the reflex arc is composed of 4 parts: Activation of sensory receptors, Conduction to and from the CNS, Transmission across the neuromuscular junction & Activation of the muscular contractile ...
0
votes
1answer
57 views

How body loses more fat in CO2 form than in sweating form? [closed]

Yesterday, I saw TV Game Show. There is question like this: Body loses more fat in which form? It gave 4 options: 1) CO2 2) sweating 3) xxx 4) xyz sorry i didn't remember 3 & 4 options. ...
3
votes
2answers
138 views

Can an argument be made that humans are 90% bacterial?

On the blog, All about Scientist in Microword: Microbiology, I read the post We are 90% bacteria, actually, which says that humans are 90% bacterial cells. If this is the case, then why don't we ...
5
votes
1answer
132 views

Colorblindness in females and random X chromosome inactivation

From Annenberg Learner: Because the X is inactivated randomly in cells, one cell could have the maternal X inactivated, while the adjacent cell could have the paternal X inactivated. This causes ...
0
votes
1answer
52 views

When does lactation occur?

High levels of estrogens and progesterone antagonize prolactin’s effect on the mammary glands, and it’s only after the placenta has been removed and the levels of estrogens and progesterone has ...
3
votes
2answers
126 views

Do intestinal flora have the same DNA as their host?

Please bear with me, this is not my professional field and I might be mixing things up. In an explanation why seeds won't start growing in one's intestines, the explanation given was that foreign ...
1
vote
1answer
64 views

Do vitamins protect you from common cold? [closed]

Do vitamins (taken as pills) boost your immune system, and make you less likely to contract diseases such as common cold or flu?
3
votes
1answer
279 views

Are there human-ingestible liquids that do not contain water?

My son asked me a question that stumped me: Is there anything a human can drink that does not contain water? It stemmed from a conversation in beverages in general where I was pointing out that they ...
3
votes
1answer
262 views

Why do humans masturbate? [closed]

Why does masturbating seem to be like an addiction? What controls or initiates the urge to masturbate? Is it good or bad or both and why is it so? I have heard guys who say that the do it ...
6
votes
1answer
765 views

Why does a fetus drinks and urinates into the amniotic fluid?

I was reading this website saying that fetuses urinate into the amniotic fluid. It also mentioned that, because we drink the amniotic fluid, we’ve been drinking our urine for months. However, why do ...