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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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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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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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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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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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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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6 views

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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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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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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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 ...
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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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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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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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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
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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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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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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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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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
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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0answers
52 views

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 ...
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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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2answers
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Where did Neanderthals and Denisovan Man come from?

Neanderthals, Denisovans and our species (Homo sapiens) are commonly cited as closely related subspecies, even interbreeding with each other. Yet our species theoretically didn't migrate out of Africa ...
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1answer
60 views

Can the heart generate its own rhythm independent to the SAN?

My textbook and a revision guide, which I believe is a reinterpretation of the textbook, state that: The SAN initiates waves of excitation that usually override the myogenic action of the cardiac ...
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1answer
37 views

What are the brain structures directly on top of the brain stem?

I have been trying to learn the anatomy of the brain, and some information on their functions, through an iPad app called 3D Brain. Whilst going through the different parts, I have noticed that one ...
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19 views

What is the name of the wrinkles occurring in people's lips? [closed]

I was wondering if there is a name for the wrinkles occurring in people's lips. Just curious.
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1answer
43 views

Would our body adapt to changes that are not in our DNA?

If a person was to undergo a treatment or surgery at a very young age, that significantly reduced their final height, would the rest of their body adjust to the sudden change? If not; because our arms’...
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1answer
44 views

Where does the energy required to turn ADP into ATP come from? [closed]

My teacher states that in order to convert ADP into ATP, energy from respiration is required. However, I watched a video which states that energy from the son is used to turn ADP into ATP. Which is ...
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0answers
19 views

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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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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0answers
31 views

Is there a chemical compound, element or something else that could color the eye lens in purple?

I hope this is a right place to ask this question. I'm writing scifi book, and looking for information whether it is possible for any element, chemical compound, radiation or something else to color ...
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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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1answer
41 views

Lobed Nuclei still count as One nucleus?

Do the Lobed Nuclei of immune cells (such as Megakaryocytes) still count as one nucleus?
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Colour of Vein surface(tunica externa)

If vein from hand is isolated out and blood from within flushed then what will be the colour of vein surface.
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1answer
117 views

Does bone smash or smash bone theory work? [closed]

Bone smash theory is the theory that damaging bones increases bone mass over time. For example, one can moderately strike parts of their bones with blunt objects/weapons like a hammer or etc. to ...
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0answers
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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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2answers
163 views

Does human brain produce nicotine?

I had a discussion with a high school student about the effect and production of nicotine. He mentioned that nicotine is naturally produced in our brain so when the person takes to smoking, the brain ...
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1answer
24 views

Effect of the same caloric intake of different macronutrients on body weight

To gain weight, caloric intake > caloric expenditure. To lose weight, caloric intake < caloric expenditure. But what is the effect of the type of macronutrient ? That is to say : does the same ...
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Autophagy role in mortality and mental health

These days the "fasting industry", personal trainers and self proclaimed doctors on youtube make strong claims such as fasting lengthening life and improve mental health or prevent alzheimer's disease....
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0answers
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Archenteron vs Gastrocoele

What is Difference between “Archenteron” and “Gastrocoele”. Are they same or different? Gastrula is characterized by Archenteron or Gastrocoele or Both?
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22 views

Problems with plexus, ganglions

I don't know exactly what a plexus is. I have a book where is written that a plexus is an intramural ganglion. Could you please tell me what is a plexus? (Vegetative plexus)
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55 views

Why can humans tolerate eating onions but other mammals like dogs and cats cannot?

Onions are one of the many foods we shouldn't feed our pets. Looking it up, I learned that onions cause hemolytic anemia in MANY species: cattle, sheep, horses, dogs, cats, and even some primates. If ...
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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
40 views

How does a decrease in free Ca2+ result in nerve/muscle overexcitability?

I have in my notes that a decrease in free Ca2+ increases membrane permeability to Na+ so that it is brought closer to threshold, but no further details. So how does this work?
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1answer
107 views

Why do obese people heal more slowly?

I recall an obese patient who was referred to a transplant clinic as his stitch wounds hadn't healed after a year. While there's a myriad of side effects caused by immunosuppressive medication after ...
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1answer
54 views

How are fingerprints formed?

I know what influences the fingerprints to be unique always. But what actually process is taken to make these as we grow?
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30 views

Does the renal vein have a greater glucose concentration than the renal artery?

My IGCSE markscheme says that the renal vein has a lower concentration of glucose? I would expect the renal artery to have lower glucose concentration as water is lost from the kidneys. Why is it so?