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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23
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5answers
13k 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
27 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
2k 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
vote
1answer
147 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
votes
0answers
71 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
223 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
40 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
vote
0answers
25 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
75 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
votes
1answer
75 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
150 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 photoreceptors....
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
824 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
13k 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
68 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
44 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
vote
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 ...
2
votes
0answers
73 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
votes
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 ...
1
vote
0answers
49 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
vote
0answers
44 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?
0
votes
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.
5
votes
1answer
7k views

Do human anal glands have any function?

Anal glands in all kinds of animals play a range of diverse functions - providing fat for preening feathers or waterproofing fur, generating distinct scent, even repelling predators. None of the ...
1
vote
1answer
37 views

Does exercising increase the rate at which UV rays are absorbed and cause affects?

Does exercising while in sunlight affect the rate at which the human body absorbs and reacts to UV rays? As sunburn is the secretion of fluids, increased dilation of blood vessels and inflammation of ...
3
votes
2answers
169 views

Do people with gout live longer?

Antioxidants reduce damage to tissue (by scavenging the free radicals) and thus may reduce ageing.It is known that Uric acid is a very good antioxidant. People with gout have excess accumulation of ...
1
vote
2answers
110 views

Are human beings evolved to eat meat? [duplicate]

I know humans can cook, and prepare almost anything, but are humans specifically adapted to eat meat. One of my doubts humans are not particularly well adapted to eat meat because they lack canine ...
0
votes
0answers
42 views

What happens to the mold spores we inhale?

What happens to the mold spores we inhale? I'm guessing when we exhale, many of them are expelled back out to the environment. But given that disease can be caused by mold exposure, I'm also ...
5
votes
1answer
1k views

Why do we get 'bags under our eyes'?

Why do these circles form around the eyes if somebody is tired? And why does fatigue express itself around the eyes this way? Can I get eye bags very quickly in another way? http://www....
5
votes
1answer
2k views

What is our skin made up of?

Again, it is a basic question. What is our skin made up of? is it made up of many cells arranged in a systematic way or is it just like any layer say of a book?? what is the difference? where is the ...
0
votes
0answers
29 views

Does the source of caffeine affect the biological impact?

I've recently decided to give up my morning coffee in lieu of a caffeine pill. Both are around 200mg (my Tim Horton's XL 4x4 was 240 mg of caffeine) of caffeine. We were talking about the various ...
1
vote
2answers
77 views

How does the mechanism which controls blood pressure in the brain work? [closed]

I've heard that the blood pressure in the brain is organised by a special mechanism. What is that and how does it work?
1
vote
0answers
16 views

Is the efferent arteriole a pathway for filtrate through the nephron ?

I am studying the urinary system. I have to identify what part of the nephron is not a pathway for filtrate. I believed the collecting duct is not a pathway for filtrate because once the filtrate ...
1
vote
1answer
111 views

What causes swelling after impact?

Why does the head swell after getting hit by something hard? What is the liquid that forms after impact?
3
votes
2answers
89 views

Crossing over and exon shuffling?

Campbell Biology 10e, in discussing the functions of introns, writes: The presence of introns in a gene may facilitate the evolution of new and potentially beneficial proteins as a result of a ...
0
votes
0answers
11 views

how to see prefrontal cortex works normally by a test?

Is there a test to see if the Prefrontal cortex of someone works normally? especially a simple test like a questionnaire that you give the individuals to fill out and based on their answer you obtain ...
17
votes
3answers
472 views

Why would diffusion be faster across a non-specialised tissue?

The standard protocol for a person experiencing chest pains is to chew a 300mg aspirin tablet, the argument being that chewing rather than swallowing the tablet results in the aspirin entering the ...
2
votes
0answers
22 views

Did the number of rods changed from ancient time?

Correct me if I am wrong, but I know that rods work under limited light conditions only. But now we are in a world that always have lights everywhere unlike ancient time when humans had to deal with ...
0
votes
1answer
37 views

Difference between the spinal cord and vertebrae column [closed]

What is the difference between the spinal cord and the vertebrae column, they both run through from the head to the abdomen. Does any one have any idea.
1
vote
0answers
18 views

What is the difference between chloride shift and Bohr shift?

Does anyone know the difference between chloride shift and Bohr shift? Is it that Bohr shift happens in respiring tissues when CO2 concentration is low, and that Chloride shift happens in the blood ...
2
votes
1answer
51 views

Do the antibodies in a patient suffering from Hashimoto's, attack the thyroid hormones or the thyroid gland (or both?)?

If oral thyroid hormone supplement is administered, is the attack stopped or does it just create an excess of thyroid hormones so that even after a lot of it is destroyed by the antibodies, there is ...
1
vote
0answers
54 views

Model for Oxygen diffusion into tissue? [closed]

Currently I have an idea and want to research it's feasibility. I want to know how oxygen or any other particle could diffuse into the body through small holes in the skin. is it possible to ...
2
votes
2answers
250 views

Do people often blow out the air from their lungs a lot when living in the cold condition to keep their lungs warm?

Do people often blow out the air from their lungs when living in cold climatic conditions to keep their lungs warm? I ask this question because it could connect to how people in different areas ...
1
vote
1answer
45 views

What is a catalytic domain?

I have to answer a few questions from an article I'm reading, and I am just really confused on defining "catalytic domain." I have to relate it to the antibiotic Teixobactin. Is catalytic domain the ...
6
votes
1answer
7k views

How does prolonged exposure to high frequency noise affect hearing?

Is there any research showing how prolonged exposure to background noises, particularly high frequency noises, affect hearing abilities? Does constant high pitched noise cause damage even a low ...