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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12
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1answer
182 views

Why do doctors still advise HIV+ couples to wear a condom during sex?

HIV infected people already have HIV, but why do doctors still advise condom use for HIV+ couples?
1
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0answers
26 views

How quickly can lasers of various wavelengths and powers impair human vision or cause pain in the eyes?

There is a discussion on HackerNews about how self-driving cars might be susceptible to confusion attacks using a cheap laser pointer and a RaspberryPi. Some people argue that human drivers, too, are ...
2
votes
2answers
90 views

It's right to say coding sequence is part of exon sequence?

Some basic ambiguities making me confused. I downloaded 5'UTR, CDS, 3'UTR, and exon sequences, separately from Biomart for a gene P4HA2 (Homo sapiens) and found some simple sequence repeat (SSR) on ...
0
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0answers
11 views

how is humidity related to amount of water we should drink [duplicate]

Is there any kind of relation between humidity and the amount of water we should drink. I know there is a relation between the temperature and the amount of water needed by the body. Do we need to ...
1
vote
1answer
63 views

What is difference between several mRNA RefSeq for one gene?

I'm looking for mRNA RefSeq sequences for a given gene in the UCSC genome browser by searching gene name "HLA-F" in human (scroll to Refseq genes section). There are several RefSeq mRNA for the gene, ...
1
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0answers
61 views

Can bigger persons generally resist g-forces better?

I've seen a claim that bigger persons generally resist g-forces worse than smaller in an undergraduate biology book. However this claim was supported by the argument that blood has to travel a longer ...
0
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0answers
40 views

Why do we pass out when we are under attack?

It is known that we might pass out, but not die, when we are under attack, e.g. got striken at the neck, blown by blunt object at the cerebellum etc. Wouldn't it be more "advantageous" to be conscious ...
0
votes
1answer
92 views

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 ?
0
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0answers
22 views

Is it better to eat something that is more or less related to humans?

My question is, would it be better to eat something like a sea cucumber or would be it better to eat a chimpanzee? Maybe this isn't a dichotic answer. Is it better to eat something in between, like ...
0
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0answers
52 views

What options are there to consume water and can you survive on them alone?

I thought about this a while, i can think of several ways, but i am not sure if there are other options and if you can survive on them alone withou dying of dehydration (lets ignore other problems ...
3
votes
1answer
120 views

How is pain induced by blunt and sharp objects?

Normally, when something touch you, you won't feel pain. With a great force "touching" you, you will feel pain. However, if something that is spiky makes contact with you, you will feel pain. So, how ...
0
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0answers
106 views

Why I don't feel pain when I press the skin on my knee and elbow?

Does the muscle on our knee and elbow have some speciality ? Why are we unable to feel any sort of pain when I pinch it ? I also did it with my Mom and Dad and result was same .
3
votes
2answers
144 views

Is there a way to prevent an HIV infection after exposure to HIV infected Blood?

If a person is accidentally injected with blood from an HIV+ person, is there a treatment option that can keep the person from developing an HIV infection?
4
votes
0answers
127 views

Why are lips covered with specialized skin?

I found out some interesting facts while studying our lips: They are covered in glabrous skin, while most of the skin surface is hairy; The outermost layer (stratum corneum) of the skin is far ...
0
votes
1answer
33 views

Marker validation using transcriptome and genomic sequences derived from a single cell

I conducted a SSR marker analysis using bioinformatic tool on some RNA-seq data of human tissues. Now, my supervisor believed that we have to validate these SSR on a transcriptomic and genomic ...
5
votes
1answer
404 views

Why do men grow facial hair?

Ancestral facial hair. Our closest ancestors, the chimpanzee and bonobo, both grow facial hair around the mouth area. What is noteworthy is that this is the case in both males and females of the ...
4
votes
2answers
570 views

Why can humans feel electricity?

What evolutionary process has provided humans with the ability of feeling electric current? Besides lightning and electric eel, what natural hazards include electricity that poses a threat to humans? ...
1
vote
0answers
56 views

Why do we turn darker in the sun? [duplicate]

I tried the all powerful google to answer this question - but I am not getting the answer I seek. I know we turn darker because the skin produces melanin. The question remains - why darker? I am a ...
4
votes
1answer
178 views

How late in a human pregnancy can a zygote split?

This page indicates that the first two days is "very early" for a zygote to split, and that conjoined twins are the result of an "extremely late" split: If the zygote splits very early (in the ...
2
votes
2answers
241 views

Can the human body enter “Power Save” mode? [closed]

Once a year, I am fasting for 24 hours. No food or drink at all for whole 24 hours. Recently I thought about what is happening to me during those 24 hours, and realized there might be something ...
11
votes
3answers
841 views

Why we do not get hurt from HCl secreted in the stomach?

I read in my book that during digestion our stomach secretes hydrochloric acid ($HCl$). Why we do not get hurt from it? It was also said that mucous provides protection, but from where is it coming?
0
votes
1answer
139 views

Cancer in myogenic heart cells? [duplicate]

Why cancer does not occur in myogenic heart cells? Is there any special ability in heart cells to resist cancer ?
1
vote
3answers
166 views

Why didn't humans evolve to reproduce identical twins all the time?

According to the selfish gene theory, it seems like because identical twins sometimes get produced, a mutation to a gene that says, "if you have an identical twin, be fully altruistic towards them" ...
0
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0answers
51 views

Proteins and Blood Acidification

Is there evidence to suggest that excessive consumption of Whey, or similar proteins will lead to acidification of the blood?
1
vote
1answer
566 views

Why do sneezes come out the mouth?

As anyone who's ever sneezed can tell you, it's caused by irritation in the nose. And the answer to a question on this very SE attests that "sneezing is a reflex, partially autonomous, to clear the ...
5
votes
2answers
550 views

Can people with AIDS get tattoos?

When I do a Google search, most of the results are about whether or not people can get HIV / AIDS from getting a tattoo through dirt needles. I am, however, curious whether or not it is possible to ...
5
votes
2answers
148 views

How can a chromosome translocation in somatic cells lead to disease?

Looking at this picture... ...I get the impression that the part of chromosome is attached to other chromosome, but it is not mutated. When we assume that all genes in the translocated part are ...
0
votes
1answer
69 views

Cut strand of hair longevity?

Quick and useless question : what can be the longevity of a cut strand of hair, assuming we kept it in (good) normal conditions ? Any idea ?
4
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0answers
41 views

How does drug-induced photosensitivity work?

Some drugs (tetracyclines, for instance) can cause photosensitivity reactions—that is, some patients become extremely sensitive to the sun, developing rashes or inflammation after spending time ...
2
votes
1answer
41 views

Does alcohol really do more damage to the body of a child compared to an adult?

Beside the fact that children and teens (people under the age of 18 year) usually have less body weight than the average adult, is there a biologically fundamental difference between the damage done ...
0
votes
1answer
164 views

How long do human egg cell grow up?

I read article about alcohol harm where written that child may bear with birth defect cause mother used to drink alcohol 10 years ago so egg cell stay damages that long. I don't believe that human ...
3
votes
0answers
24 views

Why does our body exhibit bilateral symmetry? [duplicate]

Externally, we (humans) look symmetrical. However, internal organs don't show the same patterns of symmetry (heart being on the left side while the liver is on the right side, etc.). It is a bit ...
1
vote
0answers
26 views

What is the lifetime of the vasopressin receptor V2?

I was looking at the production of vasopressin receptor 2, also known as V2R or ADH-R. What I found is that it is coded by the AVPR2 gene and degraded by the Alix protein (source). But I did not get ...
6
votes
1answer
459 views

How to identify the age of a “living” person?

An Indian old man claims he is 180 years old now. 180 years old We are not able to tell he is 180 or 181 probably. But can we tell he is 90, 120, 100 or 150? Different people may age differently. ...
4
votes
0answers
77 views

Why do people die? [duplicate]

what is the reason people die naturally even though they have no known disease? I see people become physically weak at times they get old and die eventually in case they are not attacked by any known ...
2
votes
1answer
137 views

Will a 0.2g/mL sugar concentration cause vomiting in humans?

This infographic claims that the sugar content in a can of Coca Cola would cause vomiting if not for the phosphoric acid. In The First 10 minutes: 10 teaspoons of sugar hit your system. ...
1
vote
0answers
20 views

Why does a limb sting when it “falls asleep”? [duplicate]

Closely related to this question, but unanswered other than @Matthew-piziak providing a description and link that says: What is Paresthesia? Paresthesia refers to a burning or prickling sensation ...
1
vote
1answer
141 views

Can my eyes adjust instantly to my friend's glasses? [closed]

My eyesight is pretty much perfect, but I noticed that whenever I try any of my friends glasses, from really thin to extremely thick, my eyes seem to adjust to them within seconds and let me see ...
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 ...
2
votes
1answer
76 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 ...
9
votes
1answer
168 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 ...
2
votes
1answer
284 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
votes
0answers
114 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 ...
2
votes
2answers
102 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
votes
0answers
76 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
428 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 ...
5
votes
0answers
78 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 ...
2
votes
0answers
25 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
96 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 ...
15
votes
2answers
848 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 ...