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Questions tagged [hair]

Hair is a biopolymer mostly made from keratin, which grows from the skin. Hair is exclusively found in mammals.

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How can I extract DNA from horse hair?

For my project I have to find an inexpensive, quick and simple-to-use method to extract DNA from horse hair. The sample does not have to be purified because the sample will be used for LAMP and not ...
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0answers
33 views

Why are there sporadic lightly pigmented hairs in facial hair?

My body and scalp hair are entirely black. Until recently, I thought this was the case with my facial hair also, until I noticed a small handful of hairs that were anywhere from light brown to copper-...
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1answer
109 views

Identify the fluff that I have found in tea

I have just opened a new pack of a black Pu'er tea that I've bought at the local store selling it by weight, and found a piece of fluff in there. To me it looks much like some kind of a bird fluff. It ...
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39 views

Hairlessness in humans [duplicate]

I was wondering if there is a scientific consensus about why humans have evolved to have relatively little hair in comparison to other apes. I may be conflating, but the only explanation I can come ...
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1answer
92 views

Do individual mammal hairs absorb water?

In my look into the world of shaving I've seen claims that it is better to shave after a shower because the hairs will absorb water and soften, making the shave easier. Likewise, I've seen it claimed ...
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1answer
90 views

What is the biological/evolutionary advantage to baldness? [duplicate]

Male pattern baldness is a common genetic trait. With a distinctive pattern/ density gradent (as apposed to general old age thinning as the body ages) Hair has an advantage of protection from the sun/...
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1answer
63 views

Why do men have a greater chance of suffering from hair loss?

If we look around we'll find that men are more likely to suffer from hair loss when compared to women. Is there is any specific reason for this?
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744 views

Why does brown/blonde hair color change, but black hair doesn't?

When you have light brown hair for example, it turns blonde in the summer because of the vitamin D of the sun. But black hair is better at absorbing warmth, so also vitamin D right? Then why doesn't ...
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66 views

Why does my hair do that?

I’ve been doing this since I was a child, could never really understand why. So, if I take a single hair from my head and hold it firmly between the nails of my finger and thumb, and then while ...
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1answer
849 views

Why does our hair turn white before we get old? [duplicate]

White hairs are considered a sign of old age, but they often occur in young boys. I want to ask why my hair is turning white? And why black hair turns white?
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2answers
192 views

What is the structural/chemical difference leading to different shapes in facial/head/pubic hair?

Different hairs have different shapes, thicknesses, properties. What exactly is different between these types of hairs? a previous post implies that the root of the differing length (pun intended) ...
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0answers
44 views

ls pulling off hairs really a stimulation factor for growing lost hairs?

In a medical magazine I read about new research which was done at the University of Southern California which stated that pulling off hairs helps for growing lost hairs because of its role as a ...
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1answer
159 views

The onset of hair loss in men

I've seen men starting to lose hair in almost all ages. Why is the onset of hair loss in men different? Is there a normal distribution?
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38 views

Number of hair cycles in humans

I've seen several websites claim the amount of hair cycles a follicle will go through is predetermined at around 25-30 complete cycles. Is there any genetic evidence to validate this claim? How can ...
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1answer
67 views

How large are the inner ear hairs?

I was always under the impression that the auditory hairs located deep within the ear, past the ear drum, are microscopic. After taking a shower today, I was softly padding my outer ear with some ...
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0answers
52 views

What is the Biological Mechanism by Which a Red Heifer's Skin is Colored Red?

Obviously from this picture Picture of a Red Angus Heifer it is possible for there to be a red cow. So what is the biological mechanism that makes such a cow red? And why are regular cows only ...
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1answer
84 views

Whitening of hair at old age [duplicate]

Human beings have evolved from their ancestors to their modern forms adapting many changes in structure and I would assume that every change has a significance. So, what is the cause of our hair ...
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0answers
35 views

Can hair follicle miniaturisation affect hair color?

We all know that follicle miniaturisation affects hair texture, making it look thinner(the hair shaft/root itself will be thinner), but does it affect hair color as well? So if an individual has thick ...
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0answers
69 views

Why does the scalp hair become grey first?

I understand that when the hair follicles produce less melanin or stop producing melanin altogether, hair becomes grey. But it seems like it is the scalp hair that becomes grey first. If follicles are ...
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1answer
18k views

Why do Asian people have black hair and Northern people have golden hair? [closed]

I have got two questions. Why do all Asian people have black hair? Why do all people from the northern countries (Sweeden, Norway, Finland) have light (golden) hair? Thanks for an answer.
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0answers
303 views

Why do hair on head not get pilo-erected?

Whenever we have "goosebumps", there is a momentary piloerection, due to which hair on our elbows and legs get "erected" and "stand" almost perpendicular to the surface of our skin. But why do our "...
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1answer
2k views

What does static electricity generated by plastic combs do to our hair?

It is said that wooden combs should be preferred to comb hair as compared to plastic combs. Reason is that plastic combs generate static electricity. Question: What does static electricity do to our ...
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0answers
54 views

Pigment returning to my grey [closed]

In the past I dyed my hair to cover the grey, but it became a more frequent event so I decided to just go grey. My hair has been almost entirely white for nearly 20 years. The pigment has been ...
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1answer
1k views

Why do some moles grow longer and darker hair than the rest of the skin?

In different parts of the body I have skin moles or in medical terms, nevus. In some of them hair grow seemingly either darker/thicker (I'm not sure how much of the two) and notably longer. Here are ...
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1answer
7k views

Do pulled hair from the root grow back?

There is not much to explain, I'm wondering if pulled hair, for example of the head, normally does grow back again or not. In reddit, It says this may depend on the follicle integrity, if the follicle ...
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1answer
207 views

Why does hair know when it needs to stop to grow [duplicate]

I'm still not quite sure if head hair grows endlessly, or if it stops at some point, but that's not the question. When the hair on my leg grows, it obviously doesn't grow endlessly, but it also stops ...
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1answer
199 views

Hair becoming white in one night after tremendous stress

You have surely heard about soldiers during the war whose hair became white in one night due to the tremendous stress. I was wondering how is this possible biologically ?
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1answer
415 views

Is Infra Red light safe to use on your scalp? [closed]

I own an Anodyne Infrared therapy device which I use to treat ligament/tendon/muscular pains and it works nicely. I see other infrared products used to combat hair loss (e.g. https://www.amazon.com/...
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0answers
164 views

Were Neandertals as Hairy as We Are?

What I mean to say regards facial and androgenic hairs. There are many theories as to why some people have both kinds of hairs, while others have one or the same and others still have neither. The ...
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3answers
6k views

Why are bald heads so “shiny”?

Why do males with baldness have shiny skin on their head, whereas we don't experience such "shiny skin" in other parts of body without hair.
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1answer
151 views

Why does the wavelength in curly hair differ?

Different people and animals have different wavelengths in the curls in their hair. I understand what purposes hair serves in protecting the skin from light and bugs. I am wondering about the eventual ...
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0answers
20 views

Why human hair is losing its color over time? [duplicate]

Human hair is losing its color over time, that's a known fact. I would like to know why, meaning what biological processes are involved in this? Also, is it part of the DNA somehow, i.e. the exact ...
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0answers
509 views

Why do some men have patchy beards?

Why do some men have patchy beards? Or more specifically, why would some hair follicles lack sufficient 5-alpha reductase while others nearby don't when their genetic code is identical and they are ...
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1answer
19k views

How do disulphide bonds in hair cause curling?

I understand that there are several characteristics of curly hair which differ from straight hair (such as an asymmetrical distribution of disulphide bonds in curly hair), but really am struggling to ...
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0answers
51 views

What determines the length to which hair grows? [duplicate]

Correct me if i am wrong, if we cut 2mm from eyebrow hair, it will grow 2mm and then stop growing, or if we cut 5mm, then it will grow only 5mm. My question is, does hair know how long to grow ?
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1answer
182 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 ?
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0answers
91 views

Why do human have continuously-growing hair on their head? [duplicate]

Why do hair continuously grow on human heads, while the same doesn't happen on other parts of the human body? Where there are hair, they only usually grow to a fixed length; but they seem to have no ...
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1answer
682 views

DNA extraction methods for hair?

TLDR: Can anyone state a extraction and isolation method(s) for genomic DNA for hair that will be used for PCR, in detail is preferable since I am a novice. I tried googling for DNA extraction ...
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0answers
56 views

Would it be possible to create a gel, holding viruses, that could alter the human genome when rubbed in?

I was wondering if it could be possible to engineer a virus, that when it comes into contact with human hair follicles, it could alter someones natural hair color. Naturally blue hair anyone? ...
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2answers
571 views

Did baby bird hair and mammalian hair convergently evolve?

Chicks (baby of chickens) and ducklings seem to have fine hairs, at least something that look like hairs to me. Most mammals have hairs, but reptiles, fish, or other animal groups do not have hairs as ...
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0answers
40 views

Does the use of a Thiazide diuretic affect the ability of a hair follicle to absorb substances?

Thiazide diuretics are on the World Anti Doping Agency's, as well as the International Olympic Committee, list of banned substances due to it ability to mask illegal substances in urine. The rapid ...
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1answer
2k views

Redheads and pain receptors

I remember reading this in a biology textbook, and decided to do a little digging. Redheads have a lower sensitivity to some pain and a higher sensitivity to other compared to people of other colored ...
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0answers
142 views

If what we eat can be seen in our hair, then to what degree can our food affect the “look and feel” of our hair?

It looks like most things (or everything?) that we consume, whether it is a food, drink, or something we smoke (like e.g. some drug like marijuana) ends up in some amounts in our hair. If this is the ...
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5answers
20k views

Why does hair grow after trimming but remains at a constant length after a while?

Some hair especially body hair regrows after trimming but stops growing after a while. What is the mechanism behind control of hair growth and how is the length limit determined?
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1answer
3k views

Why does hair thicken and become more rough after a razor shave but not after one using a trimmer? [closed]

If a razor cuts only the hair, then how does hair thicken and become more rough with a razor shave and not after one using a trimmer? If both are used for hair removal, why is there a difference in ...
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1answer
320 views

Safe level of chlorine in water [closed]

Chlorine is usually mixed in water to make it safe for consumption. What is a safe quantity of chlorine that can be consumed? What are the side effects of chlorine and does this include hair loss? ...
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1answer
70 views

Do hairs in the ear respond to things like shampoo?

Shampoo and conditioning products make claims to be the end all be all in hair care. I doubt that they are so advanced "growth formula/anti-breakage/oily treatment". Have any of the claims been shown ...
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4answers
6k views

Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
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1answer
636 views

Does gray/white hair turn gray/white from a normal hair? or does a gray/white hair actually grow gray/white originally?

I am really curious if hair actually tuns white/gray from default color, or does it have a defect as it is made and grows out of your head a different color?
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1answer
542 views

What is the use of shampoo; is it for the hair or for the scalp?

Apologies for the confusing question; I did not know how to better ask it. I was doing a search on wikipedia when I found this statement. Wikipedia's entry on hair states; "The hair that is ...