Questions tagged [human-biology]
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 molecular basis of hangovers?
Well, most of us have experienced the wonderful feeling of the dreaded hangover. How does it work exactly? I imagine it has something to do with dehydration but what are the underlying mechanisms?
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Do human-ape hybrids exist?
Since humans and apes share up to 99% of their DNA, can they interbreed? For example, a horse and a donkey seem to be just as distantly related and produce offspring. Mules, however, are sterile. ...
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Survival curve in early humans
The survival curve/function describes the probability of a given individual to survive to age $x$. In humans, today's survival function is very much influenced by medicine. This leads me to wonder ...
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Why do people sing?
I was wondering the why people sing, but from a biological point of view.
Is it necessary for our body? If it is so, then why can't everyone sing well?
Is it in direct relation with neurotransmitter ...
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Is it biologically possible for an adult's eye color to change?
Can it be that the adult eye can change color? Specifically my question is about a unilateral color change, such that the color of one eye remains constant, while the other changes color over time. ...
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Is the human body composition real?
In Fullmetal Alchemist when Ed goes to disprove to Rose the Sun God's "miracle" to bring humans back to life by proving that science (in the form of Alchemy) can create people by saying
Water (35 L)...
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Could humans choose to establish fibre digesting colonies in our guts?
Humans don't digest fibre, and nor do any animals, but some creatures have micro-organisms (bacteria, I'm guessing) in their gut which digest fibre for them. My question is, could humans take some ...
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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 ...
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Can food swallowed when a person is upside down reach the stomach?
If a person positions him/herself upside down and swallows food, will it reach the stomach against gravity? If so how?
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How is there no limit to a human lifespan again? [closed]
It's probably just misconstrued pop science, but I thought a read an article recently that said there's no known limit on how long humans can live. I could have sworn though that there were a few ...
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What are differences between formation of embryonic disc in chick and mammal embryo?
Exam question which got lowest average points in my university: 1/5 average.
No markscheme available so my attempt below.
I assume that embryonic disk prefers to germ disk such that Formation prefers ...
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Relative sweetness
I have noticed that when I eat something sweet, then afterwards, I eat something else that is sweet, the second sweet food is not as sweet as it usually is. I am pretty sure many others have a similar ...
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Why do we yawn?
I've read a new study which suggests that yawning may help you keep a cool head. Also, the findings might hold some hope for sufferers of insomnia, migraines, and even epilepsy.
Is there any ...
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Does homeopathic or herbal treatment of cancer have any scientific recognition?
Even though we have a very high tech society, cancer is still a serious issue. We humans still are not entirely capable of fighting cancer.
Radiation and chemotherapy are still considered the best ...
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Can drinking caffeine, alcohol and other diuretics be part of a good drinking regime?
Tea, Coffee, Beer, Coke etc…
I wonder if the benefit from amount of fluid we get from them is bigger or smaller then the handicap of dehydration. In other words it is worth to drink them if we want ...
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What fraction of human cells gets infected during a viral infection?
As I understand, if a cell gets infected during a viral infection then it eventually dies. If an individual does not die of an infection, the percentage of cells that gets infected in the course of ...
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How much heat can a human sustain?
For how long can a human sustain a temperature of 180 degrees Fahrenheit (82oC) without damage in a confined place?
For instance, suppose a person is sitting in a steam-filled room, without external ...
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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 ...
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Elevated position effect on recovery times from upper respiratory infections at rest?
In nursing school, they advice for people with upper respiratory infections to be in a slightly elevated position at the head region when sleeping.
My intuition of the reason is that the lymphatic ...
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List of heritability estimates in humans?
Many people on this site ask questions that directly or indirectly have to do with heritability in human.
Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
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Which was the last significant event in human evolution? What's next?
At 10.000 BC (12 ka), we became the last of the Homo species on Earth. In evolutionary terms this is a very little time range to something happen, but I'm wondering anyway, in this meantime which are ...
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Why do humans seem to be the only mammals that like spicy food?
Peppers evolved chemicals like capsaicin to discourage animals from eating them, and that chemical itself can cause internal damage if consumed in large quantities, though this is usually only a ...
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Determining a patients biological age?
I am looking for an algorithm that shows the exact coefficients some variables that have on a hospital patient's chronological age versus their biological age.
I understand a lot of the variables ...
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Where does the gluteus medius attach to the greater trochanter compared to the gluteus minimus attachment?
Where does the gluteus medius attach to the greater trochanter of the femur compared to the gluteus minimus attachment? Is it above, below, next to it, etc.? Ideally I'd like to know the distance as ...
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Agony, Hydrophobia and viruses in the light of evolutionary principles
I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice.
Agony as the last stage ...
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What is the evolutionary advantage of menstruation?
I was wondering why woman have fertile periods. Based on some simple reasoning I would expect that if woman were always fertile this would increase the chance of reproduction(one of the important ...
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Why Do we close our eyes while sneezing?
Google says germs may fall on eyes from our sneeze but it happens all the time . Also it says it a part of contraction. What may happen if we sneezing wirh our eyes open ?
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How does the energy we get from food transform into mechanical motion at the cellular level?
I am curious how, food broken down into glucose powers the movement of proteins in our cells (e.g., in muscle fibers for example).
Is the thermal energy converted to kinetic energy somehow?
As a ...
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Static in limbs
I have noticed that while sitting in the Sukhasan posture(picture below) for a long time, my feet suddenly become all stiff and i am unable to move it. What I deduce from the experience is that it is ...
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Why does it hurt the next day after doing significant exercise?
I think this is a fairly common observation that if one does some significant amount of exercise, he/she may feel alright for the rest of the day, but it generally hurts bad the next day. Why is this ...
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Why Does Salt Water Help Sore Throats?
I am having some trouble understanding how salt water, a simple solution, could so effectively remove the pains of a sore throat.
I do believe that the answer is closely related to hypo/hyper-tonic ...
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How does laughing gas (N₂O) work?
Laughing gas (N2O), well, makes people laugh.
How does just a gas make us do that, there has to be some hormones at work...
So, I wanted to know how this works? What is the mechanism?
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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 ...
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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 ...
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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 ...
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What is the human energy consumption by organ?
The human brain uses about 25% of the human body's metabolic energy. How are the other 75% spent, in terms of portioning to its various systems?
I thought this could be answered by a simple search, ...
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What causes fingerprints to form and why is the pattern formed unique?
I've found research that suggests that the reason we develop fingerprints is because they aid us with feeling surfaces (Scheibert, et al. 2008) and not to increase friction and help with the gripping ...
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Where does the 'C' in exhaled CO₂ mostly come from?
When a human being exhales CO₂, what is, by the numbers, the main source of carbon atoms exiting the body in this way? I mean what class of cells, or which tissues are the biggest on a pie chart of ...
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Why did scientists state that the Omicron COVID-19 variant was a reason to get a booster?
I was watching Vox’s video, Big questions about the Covid booster shot, answered, which references the New York Times article Omicron Prompts Swift Reconsideration of Boosters Among Scientists.
In ...
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Is there any use of CO₂ in human body?
We all know CO₂ as a waste product of metabolism . Does CO₂ have any helpful role , apart from having a role in pH of blood ?
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Why was disease transfer to the Americas one-way?
It is well known that the European colonists brought many infectious diseases to the Americas, and that these had a deadly effect on the native populations, because they had no immunity to them. Were ...
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Why do people have antibodies against other blood types?
The ABO blood type divides each blood type according to whether they have the "A" and "B" antigen(s) (AB has both, O has none). People also have antibodies against the antigens they don't have (AB has ...
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What's the mechanism for being mentally tired?
I notice that after long tests, or long periods of critical thinking, my body and mind feel noticeably tired. Why does this happen? Are the neurons in my head not firing as quickly, or is there just a ...
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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 ...
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What's the smallest size a human eye can see?
During a biology experiment at school, where we would look at waterweeds under a microscope, my teacher said something about that it's impossible for the human eye to see the cells without a ...
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Supercomputer Vs Human Brain
With supercomputers doing calculation in petaflops ($10^{15}$ Calculations per Second), have we crossed the speed of Human Brain?
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Why does mint oil feel cold on the skin?
When putting (japanese) mintoil on the skin it produces a cool feeling.
You can experience this, when adding it to your bath or using a spray with mint oil on your skin. The cool feeling occures ...
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Why does the face turn pale in dangerous situations?
I know what the effects are of a dangerous situation on the brain, i.e., an activation of the hypothalamic-pituitary-adrenal (HPA) axis which eventually results in an increased heart rate and elevated ...
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Can parts of a human brain be asleep independently of each other, or vary in the times required for them to fall asleep?
I know that some birds and marine animals can continue complicated activity (swimming, flying?) while one hemisphere of their brain is asleep.
I'm interested if human brain has some parts of it that ...
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Origin, or source, of rhesus negative in human blood
This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few (~15%...