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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3
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2answers
326 views

Why do our eyes “wrap” hue from UV to IR?

On the high-wavelength side of things, we see almost-infrared as reddish, with a slight tinge of magenta. On the low side, we see violet fading into the same magenta color. Why is that? You can see ...
1
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0answers
18 views

Is the amount of blood same in the pulmonary and systemic foetal circulation?

We learn that the stroke volume is the same for the right and left side of the heart. So the amount of blood in either circulations should also be the same. (is it? I myself doubt this statement. As ...
2
votes
1answer
28 views

What is the name of the property of viruses can activate a second time, with different symptoms?

The Varicella zoster virus causes chickenpox in children and shingles in adults. It appears after the initial infection, it can go dormant in the nerve, and reactivate itself decades later. In ...
1
vote
1answer
37 views

What is the name of the property of viruses that can go dormant in the host for 30 years?

The Varicella zoster virus causes chickenpox in children and shingles in adults. It appears after the initial infection, it can go dormant in the nerve, and reactivate itself decades later. My ...
9
votes
2answers
2k views

How do people who have lost both of their legs produce red blood cells?

As far as I know, just leg bones produce red blood cells. So, how people who lost their both legs produce red blood cells?
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0answers
16 views

Variation of human body temperature during physical exercises [closed]

I'm currently doing a research on "Variation of human body temperature during physical exercises". I have to study about Heat equation in 1-D , 2-D and 3-D. Are there any good resources that I can ...
3
votes
0answers
40 views

What is the name of the category of viruses that affect only one side of the body?

The Varicella zoster virus causes chickenpox in children and shingles in adults. When the virus attacks as shingles, one of its distinguishing characteristics is that it only affects one side of the ...
4
votes
0answers
66 views

When and why did humans start disliking the way we naturally smell? [closed]

Like many animals, humans produce a myriad of scents from sweating, bacteria, possibly pheromones, etc. Many of these scents are used throughout the animal kingdom for mate choice, recognition of ...
1
vote
1answer
44 views

Lookup for transporter locations in humans

I am interested in several transporters and cotransporters (eg SLC12A1/2 and many others), more precicely, in (human) organism that are made of cells containing those transporters. So does anyone know ...
3
votes
3answers
302 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 ...
7
votes
2answers
9k views

Why does plucking nose hair cause tears in the eyes?

It's not a particularly sad or painful thing to pluck a few nose hairs, but it's common for the tear ducts to wet up when doing this. I would like to know the physiological reason for the ...
4
votes
0answers
31 views

Does variation in human gut length vary predictably with diet of ancestors?

Background: Numerous online searches, textbooks and other sources seem to pin the average length of the human gut from mouth to anus (oroanal) between about 5-10m in length. To pick a reputable ...
1
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0answers
25 views

What are the most efficient sources of nutrition to add lean mass? [closed]

In conjunction with an exercise routine, what sources of nutrition will best help increase lean body mass. Most non-hormonal exercise supplements risk causing liver damage and gout due to excess urea ...
2
votes
0answers
51 views

Real Wine and Real Bread Superfoods? [closed]

On NPR news on the Fm Radio a doctor said wine and bread is the best 2 things you can eat together? A practice observed to this day by Christianity although the bread and wine are badly stripped of ...
3
votes
1answer
81 views

Does our brain contain an innate function about closing only one eye?

I wasn't sure where to post this, but biology seemed fitting for me. Sorry if I'm wrong. I was wondering why, when we close both our eyes and look at light, it is clear we can see the light even ...
1
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0answers
53 views

How would a human brain change if it existed in isolation? [closed]

How would a human brain change if it didn't receive any signals for a longer period of time (e.g. 1 month)?
2
votes
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
1answer
94 views

What are the highest and lowest amplitude values in ECG for humans?

I'm currently trying to parse the records captured from an ECG device and display them on a mobile application. I am wondering what the highest and lowest possible amplitude values for ECGs are in ...
1
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0answers
30 views

how to visualise a network of proteins complex? [closed]

I would like to know how to visualise a complex of several proteins lets say I have a list of proteins ...
28
votes
2answers
5k views

How long do your eyes need to adapt to darkness and reach full contrast?

I heard you should wait some time until your eyes adapt to darkness and are able to see smallest luminosity differences, otherwise you might overlook faint objects in the ocular. Are there any rules ...
2
votes
2answers
52 views

awakening effects of light

I tried reading by light from a neighbouring room and felt sleepier than if my own lights were on. Is there a formula for the intensity of light vs physiological preparation for sleep(calcium, ...
23
votes
5answers
12k views

Why do the two hemispheres of the brain control the opposite sides of the body?

Why does the left hemisphere control the right and the right hemisphere control the left? I googled it but didn't find a good answer regarding this. Could someone explain? Does this adaptation help ...
0
votes
1answer
26 views

Irradiation positive effect on humans?

In research paper Euphytica 135: 187–204, 2004 it is written that: 434 mutant varieties of rice have been released with improved characters such as semi-dwarf height, early maturity, improved ...
3
votes
2answers
1k views

How long do viruses, such as Zika, stay in the body?

Can a virus stay in your body (after recovery) in a concentration that is sufficient to infect someone? Is it known how long the Zika virus persists in the body?
1
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1answer
141 views

Would urination continue after death?

If someone was urinating, and they were to hypothetically suddenly "fall dead" (the brain is unconscious and all muscles / organs are unfunctional), would they continue urinating or would it stop?
0
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0answers
65 views

Why doesn't hair grow all over your face?

Why doesn't hair grow all over your face? Surely hair on a face would have blocked the sun and kept it warm. Or perhaps through natural selection we opted for hairless faces over hairy ones?
3
votes
1answer
216 views

Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
2
votes
1answer
38 views

How fast is the patellar reflex?

I have found a lot of content on the patellar reflex, but I cannot find any studies on how fast the reflex is, from onset of stimulus to innervation of muscles. Does anyone know of either a study or ...
1
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0answers
20 views

How many species of mites live on the human body?

How many known species of mites regularly live on the human body? I've always heard that most people have eyebrow mites. This source mentions 2 species of face mites, Demodex folliculorum and D. ...
23
votes
2answers
5k views

Is it possible that by mutation a human could see infrared or other 'colours'?

Incoming light reacts with the several types of cone cells in the eye. In humans, there are three types of cones sensitive to three different spectra, resulting in trichromatic color vision. Each ...
1
vote
2answers
71 views

Metabolic activity postmortem

I read some papers about studies on metabolism in post-mortem tissues in human, but I do not exactly the reason about why our brain continues to have activity after death.
0
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1answer
73 views

What were the main discoveries in Biology? [closed]

What were the greatest achievements in Biology? Can you please provide a short list of discoveries that you would consider as being the most important discoveries of the history of Biology.
4
votes
1answer
145 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 ...
7
votes
1answer
230 views

How is color information transmitted from the eye to the brain?

Is color information sent from the eye to the brain frequency-modulated, or are different colors transmitted by different axons? I know that each ganglion cell is connected to multiple ...
21
votes
1answer
2k views

Is kissing a natural human activity?

The word natural here is meant in contrast to it being a sociological construct. Is kissing in all its forms something natural for humans? Is it instinctively erotic? Or is it just a conventional ...
4
votes
1answer
770 views

Are nutrients absorbed in human esophagus?

Following this question regarding absorption in human oral cavity (sadly not yet fully answered), I'm curious if any nutrient absorption occurs during the descent of food through the esophagus. And ...
5
votes
3answers
12k views

Is it possible for a child to grow taller than their tallest parent?

I have heard that offspring can't grow taller than either of their parents but I've also heard that sometimes some gene activation can skip generations. Is it possible for a child to grow taller than ...
15
votes
3answers
4k views

In Japan, the official average body temperature is 36.0 °C. Why so different from that of Europe?

The Japanese Wikipedia states that the average human body temperature is 36.0 °C (here,"ヒト"). The statement references the data from the Japanese government. Actually all of my Japanese friends think ...
0
votes
1answer
65 views

What is the correlation between hand and neck flexibility? [closed]

I am trying to understand this statement in the book, Mudras, Yoga in your Hands by Gertrud Hirschi: There is a direct relationship between the hands and the neck since the nerve paths run through ...
0
votes
1answer
41 views

What's the mixture of plasma and haemoglobin called [closed]

I know of oxyhaemoglobin but the mixture of plasma and haemoglobin in the blood gives what?
0
votes
1answer
52 views

What's the mixture of carbon and haemoglobin called [closed]

I know of oxyhaemogloblin , the mixture of oxygen and haemoglobin , but carbon and haemoglobin combination is what's confusing
1
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1answer
62 views

Can someone help me answer or explain how to answer questions about DNA coding capabilities? [closed]

How is it that a DNA coding system with only 4 bases can yield so many possibilities? Also, how many unique coding sequences can there be with a DNA code that is 8 base pairs long? Hint: 4^n ...
0
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0answers
85 views

Why does the Vas Deferens detour over the pubic bone?

I was surprised to learn that the vas deferens detours over the pubic bone instead of taking the obviously more direct path. https://human.biodigital.com/widget?be=u1P&uaid=1ly5V Because I would ...
2
votes
0answers
56 views

What is the function of the kidney in terms of osmoregulation and excretion [closed]

Also include the role that ADH plays I am fully aware that ADH has a role in osmoregulation but does it also play a role in exretion?
0
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0answers
52 views

Could a human heart really pump fuel up to a jet engine?

In Parks and Recreation, Chris is told his heart was strong enough to "pump fuel to a jet engine". What I'm wondering is the following: Does an extremely healthy human heart have the power to do ...
3
votes
2answers
1k views

How does Bernoulli’s Principle apply to 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 ...
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0answers
46 views

What is meningitis? [closed]

I know that meningitis is the inflammation of the meninges surrounding the brain and the spinal cord. But I still don't understand this definition. If you can broaden the definition, please do.
1
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0answers
42 views

How long does it take for blood to travel from the lungs to the fingertips?

I've noticed that a pulse oximeter at my fingertip lags my breathing effort by a noticable amount. I conclude that it takes some time for freshly oxygenated blood to travel from the lungs to the ...
19
votes
1answer
3k views

What is the speed of blood?

The speed of blood may vary from one place to another and may be quite low in the tinyest vessels compared to the biggest one. What is the speed of blood while exiting a normal human heart?
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0answers
23 views

is there any relationship between shape of the nucleus and the function of the cell?

is there any relationship between the shape of the nucleus and the function of the cell, like in the case of leukocytes, all of them have different shapes.