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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0answers
8 views

Is it possible for me to grow another inch? [on hold]

I'm 14 and a half, 5'6, and got my first period at 11 and a half. My mother is 5'5 and my dad's 5'10. Can I still grow another inch? If it helps I was 5'4.5 for 2 years but i grew the inch and a half ...
0
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0answers
8 views

Why people sweat while eating chilli? [duplicate]

What chemical causes chilli its chilliness? Also, while eating chilli, people sweat and their nose become watery and they tends to expose their tongue to cool it. What is the reason for this ...
1
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1answer
24 views

Bernoulli’s Principle in the Cardiovascular System

Below are graphs which illustrate the cross-sectional area, velocity, and fluid pressure through each vascular segment of the cardiovascular system. It makes sense that velocity and cross-sectional ...
3
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1answer
55 views

Is there a schema for how human behavior is genetically determined?

It seem one can distinguish three different kinds of genetic determinism of common patterns of human behavior: behavior that is directly wired into our nervous system, e.g. face-related mirror ...
7
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1answer
62 views

What bacteria do unborn babies contain?

This Scientific American article states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a ...
0
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0answers
14 views

Why we see a reddish vision in dark room after seeing a bright light?

When you enter a dark room after seeing sunlight or other bright light, you see a reddish speck of light hovering around your vision. This vision generally disappears after a few minutes. Why this ...
2
votes
1answer
19 views

Do the enzymes and compounds in saliva help with stain removal?

Does spitting on stains help with removal? Saliva is high in amylase that should help with the breakdown of protein rich stains like blood and semen. It also contains antimicrobial enzymes and ...
3
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0answers
39 views

How long does conception take?

I know that conception is a multi-step process. A sperm fuses with an egg. Its contents diffuse into the cytoplasm. Dad's DNA is transported to the nucleus. Proteins are gradually made from Dad's ...
0
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0answers
38 views

Why does water feel colder than air at same temperature? [closed]

If you go swimming and the water is the same temperature as the air, when you first jump in, the water feels colder then air temperature. I guess this has something to do with Heat-Conduction, like ...
1
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2answers
41 views

What would happen if brain neurons did not reduce their sensitivity to neurotransmitters after prolonged exposure?

From my understanding, neurons decrease their sensitivity to neurotransmitters by reducing the amount of receptors on the cell membrane in response to sustained neurotransmitter activity. One ...
0
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0answers
30 views

How to mimic / approach some animals/insects' anabolism?

This article states that some shelled animals - spiders, scorpions, crabs, worms and other creatures - have metal atoms in their claws, jaws and fangs. I believe through anabolism, since they eat ...
3
votes
1answer
69 views

Do our belly buttons consist of scar tissue?

I read an interesting post on Facebook the other day saying that we all have a visible scar since birth - our belly button. This got me thinking (and research for me only found results regarding belly ...
3
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0answers
35 views

Is there a mechanism by which mammals lose interest in a partner after mating?

I'm reading the book called "Cupid's poison arrow", which revolves around a rather simple assumption: most mammals, including humans have a genetic program that is responsible for ever increasing ...
3
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0answers
22 views

Why are humans mostly right-handed? [duplicate]

Most sources I've seen say that about 90% of humans are right handed, and 10% are left handed. Why is this? My only guess would be that it has something to do with different parts of the brain ...
1
vote
1answer
64 views

Is each generation getting older? [duplicate]

So we know that our sperm and egg cells get set aside relatively early so that they aren't going through unnecessary cell divisions and causing DNA damage or telomere shortening, but since each new ...
14
votes
2answers
715 views

Why does mouldy food make you sick?

Bread gets mouldy pretty quickly, and my parents (both of whom are nurses) throw out a loaf of bread after a spot of mould is seen (because "if you can see one spot, it means the whole thing is ...
2
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1answer
33 views

Why is there a compound highlighted in red in a KEGG Module search?

Considering the following module: http://www.kegg.jp/kegg-bin/show_module?M00115+C00003 why is the compound C00003 marked in red?
1
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0answers
106 views

Which of these methods is both effective and reliable in elongate muscle and tendon for use in humans: growth factors or stem cell technology

Which method is it the most effective, but also the most reliable for elongating muscle and tendons for clinical trial; using modern growth factor technology or using modern stem cell technology? ...
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0answers
33 views

Heart Rate while Eating?

I was wondering does heart rate increase during the consumption of food (chewing, starting the digestive system)?
1
vote
1answer
13 views

What information does the KEGG Module statistics page show?

While browsing through the home page of KEGG Module, I clicked the button named Module statistics. Can someone tell me what does these numbers signify? What are they the statistics of?
0
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1answer
35 views

Would a human survive eating only living ants?

After reading an admittedly foolish question about 1 googol ants vs. 1000 humans, I had a question. Could a human survive solely on eating ants (common ants, not the stinging kind, or leafcutters ...
2
votes
1answer
29 views

Why are our bodies created to itch when histamine is released by our immune systems?

Why do bug bites and cuts itch when scratching them clearly doesn't help us survive? Did our early ancestors need to rely on this itching sensation, or is it just that the receptors for itches just ...
1
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0answers
20 views

An obscure reference to a “golden vein” [migrated]

In some Yiddish literature there is reference to a 'golden vein' which seems to refer to Hemorrhoids. Is there any reason that hemorrhoids would be described as golden? Edit: In response to the ...
3
votes
1answer
53 views

What are the most important factors influencing a person’s gut microbes?

You are your bacteria! The probiotics and the antibiotics... There has been on going discussions about how our gut bacteria is important for a healthy lifestyle. Figure 1: Schematic diagram ...
2
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3answers
103 views

Blood urea nitrogen and usage of proteins?

I have been reading some books and am getting slightly confused. Here is roughly what I have read. The greater the blood urea nitrogen the greater the usage of proteins (since blood urea nitrogen ...
2
votes
1answer
55 views

How does Celiac's Disease cause people to stop growing?

In all of the sites I've looked on, one of the symptoms of Celiac's Disease is the failure to grow in children. Why would an immune attack against gluten cause stunted growth? Celiac.org states: ...
3
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2answers
121 views

Is there a short-term, very strong anesthetic, which can be blocked/delayed by other substances?

Question migrated from World Building SE. (For fictional use only, of course :) ) I am looking for an anasthetic which fulfills the following criteria: very strong effect, induces a comatose state ...
16
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4answers
2k views

Where’s the flaw in my proposed TB Treatment?

Ten years ago, I emailed a prominent lung specialist with my suggestion for a treatment for Tuberculosis. His lack of response led me to believe that the idea had no merit whatsoever – but I had no ...
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1answer
77 views

How significant is the genetic component of homosexual behaviour?

From some basic googling, I found that nobody has ever proven that people are born gay and that environment plays a great part in homosexuality. I wish to know if there is a genetic component to ...
5
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0answers
68 views

What is basis of multifunctionality of “master glands” in the endocrine system?

I have just started reading about the endocrine system and I am having some difficulty understanding the basis of distribution of glands and associated hormones. I am using multifuntionality to ...
0
votes
1answer
59 views

At what saltiness will water simply pass through us?

If water has a low salt content, it hydrates us. When water has too high salt concentration, like sea water, it drains water out of us instead when we drink it. At what salt concentration would water ...
2
votes
1answer
117 views

Why do some people burn and others tan?

Connected to What is happening when we get a tan? - Why do some people burn while other people tan? Very pale people tend to just burn while other people tan very nicely, what causes this difference? ...
12
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3answers
2k views

What is happening when we get a tan?

Almost everyone nowadays wants that nice summer tan, but what exactly is going on beneath the skin? I've heard a few different theories about tanning - such as a tan is nothing but the pigmentation in ...
1
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2answers
121 views

What is a substance that is safe to eat, not absorbed and not metabolized?

I would like to know whether there are substances that are safe for humans to consume, are not absorbed and do not interact with any digestive process. So, food is disqualified because although it ...
2
votes
1answer
50 views

(How) Does the human digestive system process petroleum jelly, aka petrolatum?

Does the human digestive system processes petroleum jelly? In other words, does it pass through the digestive system without any interaction, or is it absorbed and/or metabolized?
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0answers
24 views

How hot can coffee be for it to burn the tongue? [duplicate]

How hot can coffee get before the tongue will get burned? I want to know an accurate temperature. Specifically coffee. I felt that the other question didn't have a definitive answer.
2
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1answer
42 views

Database of medically validated SNPs

I'm looking for all possible sources of clinically tested human SNPs. There is a handful of databases that store SNPs (like dbSNP), but I only need those that have validated presence/absence of ...
0
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0answers
30 views

Why do human have continuously-growing hair on their head? [duplicate]

Why do hair continuously grow on human heads, while the same doesn't happen on other parts of the human body? Where there are hair, they only usually grow to a fixed length; but they seem to have no ...
2
votes
1answer
49 views

What causes head hair to be different than body and face hair?

If you feel your head hair, it typically feels a lot softer and is easier to manage (comb, brush, fix) than a lot of other hair on your body - specifically I'm thinking about beard hair and pubic ...
4
votes
3answers
984 views

Why is wind cold for humans? [closed]

Coming out of the pool the other day, I felt very cold because I was wet and the wind picked up. My idea is that a "cold" feeling should be associated with low temperatures, but it's indeed wrong. ...
9
votes
1answer
343 views

How do female hormones cause blood to clot?

On most female-hormone supplements you get a warning that is something like this: The use of a combination hormonal contraceptives (CHC), like NuvaRing, is associated with increased risks of ...
8
votes
2answers
126 views

Which part of human body sustains most pressure when standing up straight?

Let's suppose a healthy fit barefoot young adult standing comfortably on a flat solid surface. A reasonable guess is somewhere around the foot. But is it the ankle, the heel, or the Metatarsus?
32
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5answers
3k views

Is there an advantage to antibacterial soap?

There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap? In particular I'm ...
2
votes
1answer
92 views

What are dreams, biologically?

Falling asleep or states of subconsciousness does not stop the mind from making its own fictional images. These seem like sensations just like those received from human eyes. But, how do we define ...
2
votes
1answer
100 views

Does our heart stop when we sneeze?

Is it fact or myth that our heart stops beating for moments when we sneeze? If it is fact, what drives the heart to start beating again?
3
votes
1answer
110 views

What is the optimum length of abstinence for maximum ejaculation volume in humans?

There have been papers discussing this, and whether the abstinence period should be 1 week, 2 weeks or other [1, 2]. Some think the time to maximum ejaculation volume is even longer than this. doi: ...
10
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3answers
233 views

Why are the organs for reproduction and urinary excretion combined?

We eat food for getting energy to our body parts, and we excrete the wastes through urine, feces, and perspiration. Why has nature combined the urinary tract with the genital system (urogenital ...
11
votes
4answers
1k views

Will the heart keep beating if it is separated from the body?

The heart is a vital organ in our body, as it drives blood circulation. I was wondering if a heart keeps beating if it is separated from the body? If yes, then why?
3
votes
1answer
128 views

Do we need to drink less water in humid weather than in dry weather?

From my understanding, humid weather means that the air has a lot of water in it. Therefore, someone who lives in this kind of weather would be hydrating himself just by breathing. Does that mean ...
1
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0answers
36 views

Is there a comprehensive model of human attraction and sexuality? [closed]

I'm interested if modern (2015) biology has a comprehensive model of how human sexuality works. From my research, it appears that the drive for mating is primarily mediated by ...