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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1answer
169 views

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 ...
2
votes
1answer
74 views

Average face shape

I am doing face detection application where every face detected is inside a rectangle. The rectangle always contains some background behind the face and now I need to extract as much of the face as ...
2
votes
1answer
130 views

Development of vitreous humor

I have tried reading about development of vitreous humor but it is all very confusing. When does it first developed ? Does it renew itself ? Please provide reliable sources..
2
votes
1answer
84 views

Where does the fate map of a human embryo end?

I'm confused about the fate map of a human embryo. Is it just a particular part of the embryo development or does it include everything, from the conception (germinal stage) to the day the baby is ...
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3answers
433 views

Does our eyeball increase in size as we grow?

Does the size of the eye increase as we develop from the stage the complete eye first forms to infancy and then to adulthood ?
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2answers
119 views

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 ...
2
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1answer
84 views

For emphysema, which of the respiratory volumes is effected. I have a couple of educated answers

It could be the tidal volume because it effects how a person inhales and exhales normally. It could be the residual volume and functional residual volume, because it increases its amount. Because it ...
3
votes
1answer
249 views

What is the beneficial function of IgE antibody?

Dont tell me the "function" of IgE is to cause allergy ! In whatever texts I have seen it is written that IgE is important to cause allergies but what is the beneficial function of IgE ? Why was it ...
5
votes
2answers
245 views

Is there a biological reason for spreading food intake into breakfast-lunch-dinner?

I keep hearing over an over how humans can satisfy their entire daily caloric need in one sitting at a fast food restaurant. At the same time I'm looking at the kitchen plates, cups, etc, and they ...
6
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1answer
134 views

Task-dependent “reversed” handedness: why use left hand for some tasks? How is it controlled by the brain?

I am right-handed. Which means that when I hammer down a nail, I hold the nail in my left hand, with which I can hold it straight and at a controlled position. This is true in situations where the ...
3
votes
1answer
48 views

Why are many anti-malaria drugs gap junction antagonists?

Why are many anti-malaria drugs gap junction antagonists? My professor recently just mentioned that many of the anti-malaria drugs block gap junctions. i am wondering if this blocking is important ...
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2answers
264 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
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vote
2answers
111 views

How the lungs clear themselves?

Looking at my computer's fan I can say that a lot of dust is collected on it not less dust should be collected in the lungs, not to mention some inhaled parts of food. How the lungs clear themselves ...
6
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2answers
161 views

Why did women historically have such a high mortality rate during birth?

Historically women had a relatively high chance of dying while giving birth. At first thought it seems to me that this would be a disadvantage for the species for the obvious reason that a dead ...
3
votes
1answer
74 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
votes
1answer
52 views

What is this abbreviation CT in female reproductive system [closed]

I have this sentence in my notes Ovary is surrounded by tunica albuginea and the cortex keeps the primordial follicles. The medulla containing CT and blood vessels develop from mesonephros. I ...
1
vote
1answer
898 views

Near point and far point of myopic eye

Suppose a person wears the specs of power -6D, the far point for that person is 16cm. But the near point of normal eye is 25cm. So, is the near point of a person with myopia (having far point less ...
3
votes
2answers
367 views

How was the Huntington's disease gene's location found?

I read in the book "Why we get sick." by Nesse and Williams that: Steady detective work and fabulous luck have enabled geneticists to pinpoint the Huntington's gene on the short arm of ...
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2answers
126 views

Can excessive carbonated drink consumption lead to elevated red blood cell levels?

I've recently had a blood test and the results displayed elevated levels of erythrocytes as well as hemoglobin. (As a result my hematocrit levels were also above average) At my workplace there is a ...
1
vote
1answer
71 views

People say the cardiac cycle depends on blood pressure? How so?

I know what the cardiac cycle is. There are two phases diastole and systole. One is the relaxed, and the other is the contracted form of the heart. The diastole is where blood is pumped to the ...
0
votes
2answers
107 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 ...
1
vote
1answer
131 views

Consequence of touching Formaldehyde

I accidently touched formaldehyde some days ago. Skin on my hand got dehydrated as if I had placed it in salt solution. I washed it with water and it returned to normal state after 5 minutes. But now ...
3
votes
1answer
664 views

Why does ear wax taste sour?

Why does ear wax taste sour? I am interested in both the physiochemical mechanisms and the evolutionary reasons behind the sour taste of earwax.
2
votes
1answer
58 views

Spinal cord injury bypass

When the spinal cord is damaged, the connection between the brain and some part of the body may be lost. To restore this connection, researches are considering either: Repairing the damaged area so ...
5
votes
1answer
184 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
5
votes
1answer
1k views

What's the minimum distance of focus for the lens of a human eye to reach maximum flatness?

According to the Wikipedia article on eye accomodation, the range in which a human eye can focus is from 7 centimetres away up to essentially an infinite distance. Of course, people can't see things ...
3
votes
1answer
32 views

Functioning of BCG vaccine

I read (from Nature Volume507, S4–S7 (06 March 2014) : For reasons that are poorly understood, BCG protects only infants; it is ineffective in older children and adults. Its efficacy also ...
1
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1answer
119 views

The distance the electromagnetic field of the heart can be detected

A very smart friend of mine seems to get taken in by junk science. He started telling me last night that the electromagnetic field of the heart can be detected beyond 30 feet. What is the actual ...
0
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1answer
23 views

Association of shorter telomeres with heart disease

From this paper Those with shorter telomeres in blood DNA had poorer survival, attributable in part to a 3.18-fold higher mortality rate from heart disease (95% CI 1(.)36-7.45, p=0.0079), and ...
2
votes
1answer
3k views

Why can't ciliary muscles in the human eye relax like other muscles?

I had laser eye surgery a decade ago, but in recent years my eyesight has become significantly myopic. I consulted an ophthalmologist to see if this was eye strain because I work at computers a lot, ...
2
votes
1answer
128 views

Evolution of Homo Erectus to Homo Sapiens

I just read an article on Wikipedia and noticed that some similarities between Homo Erectus and Homo Sapiens in the "Comparative table of Homo species". My question is; Is it possible to say that ...
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1answer
50 views

Is it easier to burn a calorie of fat or a calorie of a carbohydrate?

Say someone eats 100 calories of chocolate vs. 100 calories of carrots. Something tells me that eating the chocolate will lead to you generating more fat. Will it? Is it harder to burn the calories ...
2
votes
1answer
254 views

From a purely biological perspective, how does an optimal human diet look? [closed]

There is hardly any subject as contested in the media as what humans should eat. Usually, such discussions are devoid of actual scientific reasoning, though they all claim to be backed by scientific ...
1
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1answer
37 views

Surrogacy Post Fertilization

The wikipedia page on surrogacy highlights two main forms of surrogacy: Traditional Surrogacy and Gestational Surrogacy. Traditional surrogacy inseminates the surrogate mother with sperm, while ...
2
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1answer
1k views

Is urine dirty as soon as it leaves the human body?

Human urine is sterile as long as it is in the human body. But is it dirty after leaving the human body? Could you get sick from it, if you drink it or don't wash your hands, for example?
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4answers
8k views

Can humans eat grass?

Can a human eat grass and digest it? Could it be possible to use it as food just like other plants such as wheat or beans?
1
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1answer
125 views

Raising two legs together while lying on bed

Let's do some exercise(duh!) Ok so lie on the bed. Lift your left leg. Put it down. Lift your right leg.Put it down. Easy? Now lift your left leg and without putting it down, lift your right leg. ...
3
votes
2answers
151 views

Electronic cigarettes (e-cigs), any health risks?

Background: An electronic cigarette (e-cig or e-cigarette) is a battery-powered device which simulates tobacco smoking patented in 1963 by Herbert A. Gilbert. It generally uses a heating element ...
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0answers
38 views

Nearly Exhaustive List for Cholesterol Pathways

I have run across an interesting case that is similar to only two others I've encountered. What makes it interesting is the combination of undetectable (under normal testing conditions, can elaborate ...
2
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0answers
51 views

How can one accurately diagnose human hearing loss without surgery?

In a human, if you were to avoid a tympanotomy, how could you distinguish between a blocked Eustachian Tube, a ruptured eardrum, or Perilymph Fistula? For instance take the situation where a young ...
7
votes
2answers
198 views

What causes skewed lanes in a DNA gel electrophoresis experiment?

In gel electrophoresis, what causes effects like these (see collumn 11 in the first one, an collumn 6 in the second). ? (These images were samples that I took from an online activity we did for ...
5
votes
2answers
2k views

How do we know that everybody's DNA fingerprint is unique?

How do we know that everybody's DNA fingerprint is unique? I know, I know, everybody's DNA is unique. But when we do DNA fingerprinting, we're looking at very specific regions of high variability. ...
5
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2answers
86 views

Improving myopia

I have a friend who no longer needs glasses. He previously had myopia in both eyes but over the years it has improved until he no longer needs glasses clinically. He's had glasses for over 30 years ...
1
vote
1answer
47 views

Is there a scientific name for the field of study focusing on the hemispheres of the brain and their control of opposite sides of the body?

I'm assuming this field of study would focus on motor controls, movement, and exercise, but it could also focus on activities which strengthen the corpus callosum or stimulate a specific half of the ...
3
votes
0answers
196 views

Do Asian women have more difficult births than Europeans?

I recently heard a claim that Asians in general have more difficult births than Europeans. Is this true? I have found a few studies(1,2) on the effect of ethnicity on birth outcomes but they seem to ...
3
votes
2answers
80 views

Why do humans circulate monosaccharides instead of disaccharides as in plants?

Plants transport food mostly in the form of disaccharides like sucrose but humans transport them in the form of a monosaccharide - glucose. What is the reason behind this ?
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2answers
133 views

Systemic sensory confusion?

Sometimes when a person gets touched on one part of the body they feel it else where and may think it came from a different part of the body. What causes this? Other examples are similar to why you ...
3
votes
2answers
236 views

How does the brain know where a signal came from? What is the addressing system

I am an electronic engineer so I am thinking about this from an electronics outlook. How does the addressing system work, As I see it, the nervous system is small parallel branches attached to larger ...
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vote
1answer
33 views

What are good data on the Human Metabolic Model and where can I get them?

Trying to get a good SBML representation of the Human Metabolic Model for use in Flux Balance Analysis and drug targetting (i.e. gene knockout) simulations. What are good sources for these data? ...
2
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1answer
68 views

How usable is the Human Metabolic Model to predict biomass?

In order to use the Human Metabolic Model for Flux Balance Analysis of specific cancer cell lines, we would like to know what sort of flux values have been determined for the Human Metabolic Model. ...