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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 average eye sight for humans? How bad is one's eyesight if you are1 or 2 SD below average?

What is the average eye sight for humans? How bad is one's eyesight if you are 1, 2 or 3 SD below average? I googled but it was hard to find good search terms.
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0answers
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How much oxygen does a human need to breathe?

So, I know that the title isn't very precise, but so is my current knowledge of the subject. It begs the question of what unit are we talking or maybe percentage? Let me explain the situation. Earth'...
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5answers
24k views

How could humans have interbred with Neanderthals if we're a different species?

To be clear, I'm not doubting that homo sapiens and homo neanderthalensis did interbreed: of that much I'm convinced. Within the past few years I've seen an upcropping of pop-sci articles discussing ...
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25 views

Why can we hear above 8 kHz

Why have humans developed ears capable of hearing sounds that are (never?) heard in nature. Is it known why humans developed the ability to hear up to 20 kHz when all the relevant noises are below 8 ...
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0answers
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Write true or false for the following [on hold]

a) Anaerobic decomposition of organic solids takes place in a septic tank b) Reservoir of infection for Hepatitis A is human cases only. c) Basic tools for financial management are budget and audit. ...
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How do some deep sea creatures lower their metabolism to stay alive for a long time?

I was watching some bio related videos and saw in one that some deep sea creatures and other organisms purposefully limit their movement to decrease metabolism rates. Do they live longer? If we ...
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0answers
28 views

Effects Diet Soda has on body? [on hold]

So this is probably not the right topic for this question but I couldn't find an exchange based on Health so this is the best I have. I am wanting to go on a diet and was wondering how bad Diet Soda ...
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0answers
42 views

Non-surgical methods of facial-width-to-height ratio increasing as maximizing odds of human mate selection and sexual success? [on hold]

According to science, FWHR is correlated with both sexual success and initial sex/romantic attraction. Given such, it is clear that having a higher FWHR increases chances of sexual success in males. ...
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What is the Primary factor of which potassium excretion depends?

Is the Excretion dependent on K+ reabsorption in PCT , as most of the substances are absorbed by PCT from the glomerular filtrate or does it depends on selective secretion of K+ by DCT or Both .
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1answer
128 views

Why Is Gray Matter Gray?

When I researched I found different reason for this, the popular ones are 1) white matter is mylinated .this reason was given in reference books and this website while others say 2)cell body ...
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0answers
114 views

What's a “constitutionally small penis”?

I'm reading some urology papers and came across one involving penis growth (Kim & Song, 2008); here's an intro passage that I'm confused about: A total of 58 patients with constitutionally ...
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0answers
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Can the human body survive in a zero sugar diet strictly through gluconeogenesis?

I read an article a while back about athletes (I believe cyclists) being exposed to a 0 sugar diet and their blood sugar levels stayed relatively constant, which prompted the question whether people ...
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3answers
240k views

Why do I only breathe out of one nostril?

I was just sitting with my hand next to my nose and I realized that air was only coming out of the right nostril. Why is that? I would think I would use both, it seems much more efficient. Have I ...
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2answers
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Why would taking antibiotics increase stamina and energy?

I often hear that people who are taking antibiotics experience wild fluctuations between feeling full of energy and completely alert but soon after feeling impossibly fatigued and sick. Does this ...
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1answer
279 views

How spinal cord play its roles in human beings sex? [closed]

I know most people can't enjoy sex if their spinal cord injured. How spinal cord play its roles in human beings sex?
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1answer
287 views

How is energy acquired from ATP? [duplicate]

How is energy acquired from ATP (i.e. What is the energy-releasing equation involving ATP plus water)? I Would be grateful for the answer.
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2answers
192 views

How does the body really react to exposure to the vacuum of space?

I've seen sci-fi movies where the effects the body being unprotected in outer space are wildly different. In one movie, a guy radios for someone who's been ejected into space to breath all the air ...
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1answer
4k views

Structure of adenoids

I am not sure this question belongs in biology, but I can't find a more suitable stack exchange site, feel free to delete it if this doesn't fit here. Also, this question is going to be slightly ...
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1answer
87 views

Is reverse senescence/“anti-aging” actually scientifically possible among humans yet?

I have been very interested in this since I myself am interested in reversing my skin's aging/genes/damage/etc. I also am interested in volunteering any future genetic altering of skin quality. ...
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1answer
13k views

Why don't we have hair on palms?

We have hair all over the body except palms. What is the biological reason behind this?
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0answers
13 views

How can I increase the amount of disulfide bonds in my hair? [closed]

My name is Anaël and I have been looking for several ways to make my straight hair curly. I read that hairs can be curled because the disulfide bonds are strong. I was only able to find how to reduce ...
0
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1answer
61 views

Can I train my non-dominant hand and make it dominant?

Are our dominant limbs decided on birth or is there some way in which I can train my non-dominant hand and make it as coordinated as my dominant?
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0answers
979 views

How does proximal centriole of human sperm function?

I've read that the human's unfertilized oocyte ( stuck at metaphase 2 of meiosis ) lacks centrioles and that it completes meiosis 2 after fertilization as sperm gives its proximal centriole. Then what ...
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1answer
37 views

How do astronauts eat in space?

If there is no gravity in space how does the food enter the stomach? My guess is that it is due to the movement of the esophagus.Am I correct?
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2answers
963 views

In the vacuum of space would death be instantaneous?

I was arguing with my colleague about this matter (I'm not going to mention which side I fall on). Would death be immediate in the vacuum of space? For example, if I was suddenly teleported into the ...
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0answers
46 views

Hematuria due to Nitric Oxide

Drug interactions between properly dosed NO and other medications are not expected, but side effects may include noisy breathing, hematuria, or possibly atelectasis. (pg.no:577; Goodman and Gilman ...
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1answer
108 views

Are all genetic disorders inherited?

I know that genetic diseases such as cystic fibrosis are often passed down through generations and are therefore classified as genetic disorders, but if a mutation occurs spontaneously, which for ...
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1answer
1k views

Is it possible to have sleep paralysis while sleepwalking?

At least from a conceptual level, these two disorders don't conflict. The effect of sleep paralysis is being conscious while having the inability to consciously direct motor functions. Sleepwalking is ...
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0answers
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Reason for acephalgic migraines

I suffer from acephalgic migraines, known commonly as ocular migraines. I’d like to know the reason why such migraines occur. Moreover, I’d be interested in knowing why do the following occur in the ...
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0answers
23 views

Is it possible to determine if it is the 5’-a 3’ strand or the 3’-5’ strand?

DNA is constructed in an antiparallel manner. This means if you number each of the 5 carbons in the sugar deoxyribose the 3rd carbon will be connected to one phosphate group and the 5th carbon will ...
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1answer
71 views

Surviving only on another's exhales?

While reading this - Surviving under water in air bubble - this question came to me: How long can an adult person survive on breathing in only exhales of another adult person? Can this be even ...
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1answer
34 views

Have there been new discoveries concerning the perception of taste for the last 10 years? [closed]

What are the last discoveries concerning the perception of taste for the last 10 years? We discovered the 5th flavour: umami. Also the 6th and 7th: oleogustus and starchy. Anything else? Maybe in ...
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0answers
35 views

Is there any reason smallpox would genocide the native Americans? Give specific genes or proteins Africans and Europeans have more of [duplicate]

Is there any reason smallpox would genocide the native Americans? Give specific genes or proteins Africans and Europeans have more of? Perhaps answer the questions. It would be helpful.
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0answers
29 views

Is there any explaination to homeopathies in modern biology sciences? [duplicate]

I'd like to know if there is any sort of explaination from rigurous biological arguments which could potentially explain how homeopathies could work? I'm not talking about placebo effects (...
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2answers
88 views

Are spinal nerves myelinated and unmyelinated at the same time?

I was trying to answer this question when I remembered that the somatic axon is myelinated, while both sympathetic and parasympathetic preganglionic axons are also myelinated. Are they only myelinated ...
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0answers
39 views

Evolutionary basis for medicine

As a complete non-expert, It seems extraordinary to me that minute amounts of chemicals, taken orally or in other ways can affect the regulation of body processes. Is there an evolutionary point of ...
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1answer
47 views

Do mutated c-sis oncogenes only affect cell growth?

Since c-sis regulates only cell growth, a mutation there should only lead to an out of control growth of the cell, but the cells would still be mature, since c-sis does not regulate the function or ...
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1answer
3k views

If fever is a natural immune defense, why do people take drugs to lower it?

If fever is a natural defense against pathogens, why do sick people take NSAIDs to reduce the fever?
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1answer
114 views

Is it possible for human body to convert carbohydrates to protein? [closed]

Is it possible for human body to convert carbohydrates to protein to build muscle for example? EDIT: I read in many articles that you should eat more than 1.5 gram protein for each 1 kg weight of ...
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1answer
5k views

How do bile salts affect lipase activity?

BACKGROUND: It is well known that bile salts are needed for emulsification of fats. It is then said that this increases the surface area for activity of pancreatic lipase, implying that bile salts ...
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2answers
1k views

Advantages of pain sensation?

The hazards of congenital insensitivity to pain (CIP) are well-known. This question is about the obverse: what selective advantage, if any, does the normal sensation of pain confer? I'm thinking of ...
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0answers
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True or False: Endocytosis delivers vesicles directly to the cis face of the Golgi complex

Does anyone know the answer to this question, and also the explanation of to why this is True or False? I know that Endocytosis is the process of uptake of materials into cells including ...
2
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1answer
87 views

Why is exclusive breastfeeding recommended for 6 months only?

The WHO recommends exclusive breastfeeding for the first 6 months of a child's life. Review of evidence has shown that, on a population basis, exclusive breastfeeding for 6 months is the optimal ...
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5answers
13k views

Why is the opposite of plantar flexion called “dorsiflexion”?

Why is the action of flexing the foot so that the toes move anteriorly/superiorly (i.e. in the direction opposite that which they move during plantar flexion) described as "dorsiflexion?" In the same ...
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2answers
49 views

Effects of horizontal vs. vertical motion on human body

I want to know if moving along a vertical plane in a circle differs in its effects on the human body from moving horizontally in a circle. Imagine a ferris wheel with a diameter of 50 metres. If a ...
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1answer
104 views

How can fresh cavities form at the margins of sliver amalgam fillings on teeth?

Silver amalgam fillings predominantly contain silver a known bactericidal agent and mercury which a known toxin and has bactericidal property. So how is it that the plaque bacteria survive near the ...
5
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1answer
29k views

After vasectomy, where does the sperm go?

After vasectomy, where does the sperm go? Vasectomy Procedure cuts only vas deferens, But Our Testes still produces sperm, if there is no output for sperm, where does it go?
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0answers
74 views

What are the (statistically) normal pH levels in the most-outer part of human sexual organs?

What are the (statistically) normal pH values of the outer skin/epidermis of human sex organs (groin/crotch) in the male and female? e.g male testes, female vulva, male glans, the enveloping epiderm, ...
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What is the role of plasminogen used in the preparation of APSAC? (Anisoylated Plasminogen Streptokinase Activator Complex)

What is the role of plasminogen in APSAC, and how is there indirect activation of plasmin through APSAC? Reference https://www.sciencedirect.com/topics/chemistry/fibrinolytic-agent
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2answers
2k views

What is the cause that angina pectoris is felt in your left arm?

When someone has heart problems sometimes they feel pain in their left arm. But why is the left arm painful?