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

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Naturally making green hair. What chemicals to use? [migrated]

Is there any chemical that is biologically produced in humans, that when impregnated in hair follicles, produces green hair? If current keratin follicles cannot do that, pick another biochemical for ...
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1answer
95 views

If ALL the melanin in a person was pheomelanin [closed]

If ALL the melanin in a person was pheomelanin... What would change about their appearance and what would the health effects be from such a change?
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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 ...
4
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1answer
75 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
30 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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3answers
2k 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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0answers
48 views

Why do we have butt hair? [duplicate]

Why do we have hair on our butts? From what I understand, hair is generally used for warmth, but it seems like our buttox would be one of the last places on our body that would need warmth. Moreover, ...
5
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1answer
171 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
43 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
45 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 ...
6
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1answer
310 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 ...
5
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1answer
75 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?
3
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1answer
78 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 ...
2
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2answers
105 views

Is there a medical condition in which you can't cut your hair?

Just curious, does there exist a medical condition in which a patient is advised not to or simply cannot cut their (head) hair?
2
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1answer
135 views

What is the chemical process involved in human hairs changing colour after sun exposure?

After a day at the beach, my skin tans due to Melanin. But I also observe the black hairs on my arm turn a blond colour. My question is What is the chemical process involved in human hairs ...
0
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1answer
35 views

How do cats shed their fur?

Dogs shed their fur twice a year, so I assume this is the same with cats. What is the mechanism whereby the change in temperature (assuming this is what causes the shedding) leads to the falling off ...
17
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3answers
10k views

Why can white hairs get dark again?

I have learned (probably in high school?) that hairs turning white is caused by the part of the folicle which produces the pigment dying and being replaced by an air bubble. This sounds very ...
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4answers
157 views

Significance of having goosebumps?

What help does goosebumps do to us? I don't think it helps us noticeably when we are scared or shivering.
2
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2answers
121 views

Are there free electrons in muscles, hair, or skin?

Electric shock occurs upon contact of a (human) body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair. In metals many electrons are said to be ...
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1answer
108 views

Why would the Camargue horses have a white coat while the foal have a dark coat?

The current issue of the magazine Lonely Planet India(Oct 2013) presents a photo of Camargue Horses which are white coated and mentions that they are born with dark hair. A search shows that the foal ...
3
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1answer
403 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
1
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1answer
367 views

Approximately how thick is a single strand of cat (domestic housecat) hair?

I did a little research to lead me to finding the general range of width for human hair, which is anywhere from around 30µm to 180µm... approximately. I'm trying to compare this to the width of cat ...
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1answer
293 views

How does hair grow and is it similar to how grass grows?

If I recall correctly, nails (finger nails or toe nails) grow by adding matter at its base. So for instance, if you would draw a dot at the very bottom of your nail, it would end at the top in a ...
2
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2answers
573 views

Iron deficiency anemia symptoms explanation

In my classes and on the internet, brittle nails and dry hair (or hair loss) are described as symptoms of iron deficiency anemia, but none explains the cause of such symptoms. Does anyone have any ...
9
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2answers
328 views

Chiral (a)symmetry of curly hair (and fur)

Some people have curly hair, as well as fur of some animals can be curly. However, shapes which are curly are not mirror symmetric, much alike screws or chiral molecules. The question is whether ...
6
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2answers
15k views

What could cause hairs to gray at the tips but not the roots?

I have noticed that some of my sporadic gray hairs are gray at the tip side but oddly, not near the roots. Some are even only gray in the middle. I find all of this very counter intuitive, and I ...
10
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1answer
81k views

What causes random long white body hairs?

I'm sure many of you have experienced this - you scratch your back or brush your hand over your arm and find a ridiculously long thin white hair, sometimes as long as 3 or 4 inches. I know a few ...