Questions tagged [pigmentation]

Pigmentation refers to the coloration in plants or animals due to the presence of pigment in the tissue.

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196
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3answers
32k views

Why are so few foods blue?

Although blue foods exist, they're rare enough compared to other foods for food preparers to use blue plasters as a convention. The natural colour of a given food is due to pigments that have some ...
29
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3answers
287k 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 ...
19
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3answers
4k views

Why does hair turn grey or white, and why does it happen later for some?

The question is pretty simple: what is happening molecularly when hair turns grey or white? I would imagine that it is due to the lack of a particular compound. I'm also interested in why some people'...
17
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2answers
57k views

Why do we assume that the first humans were dark-skinned?

According to the article Dark skin and blue eyes: How Europeans once looked: It is widely accepted that Man's oldest common forefather was dark skinned, and that people became more pale as they ...
17
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3answers
10k views

Are there cats with black skin?

Some mammals can have a black, pink or spotted skin, depending on race - see for example humans or pigs. But I recently learned that this is not the case with mice. Even black furred mice have pink ...
13
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3answers
4k views

Why is mammal coloration so dull?

I have seen species of birds, insects and fishes with splendid colours. But when it comes to mammals (including us humans), they almost always appear in shades of brown, grey, orange, or in black and ...
12
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5answers
23k views

Does darker skin color make it easier to live under sun?

I have always thought darker colors absorb more heat from the sun, so if you are wearing a white T-shirt you will be cooler under sun than wearing a darker T-shirt, or a black piece of steel will be ...
12
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1answer
3k views

Why is chlorophyll green? Isn't there a more energetically favorable color? [duplicate]

Chlorophyll being green means it absorbs light in the red and blue area of the spectrum. Isn't this the high and low energy light? Wouldn't plants get more energy if they absorbed light in the green ...
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4answers
4k views

Does pheomelanin have a useful biological function?

Melanin is a natural pigment that is categorized into two main forms, eumelanin and pheomelanin. It's well documented in the science literature that increased eumelanin levels reduces the risk of ...
9
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1answer
781 views

Why is carotene in carrots?

Internet says that the carotene is an important pigment for photosynthesis and UV-protection. That explains its accumulation in leaves. I suppose colored fruits are more appealing to animals, so that ...
9
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1answer
14k views

Why are certain baby (water)fowl yellow?

Why are e.g. ducklings, goslings, turkey and chicken chicks (partly) yellow? What is the chemistry background to this? What compounds from the egg cause this to happen? What is the evolutionary ...
9
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1answer
178 views

Plumage as indicator of health in birds

Anybody know which traits of bird plumage are accurate indicators of a birds health? For example feather coloration, feather brightness, amount of feather wear, number of feathers, moult timing, moult ...
9
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1answer
848 views

What biological processes cause leaves to change colours in Autumn?

I am curious to learn what are the biological mechanisms that cause leaves of deciduous plants to change colour? What happens to the chlorophyll? What environmental phenomena (temperature/air ...
8
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2answers
3k views

Why do people have darker skin in sunnier climates?

I don't understand why darker skin is advantageous in hotter climates. Wouldn't it absorb more of the heat? I have heard that it reduces the incidence of cancer, but I would think absorbing more ...
8
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1answer
11k views

What causes the colors we see in eyes?

Genetics aside, what are the biochemical reasons for the different colours of human irises? Also, related, how does eye colour change, particularly in childhood? (example: my eyes used to be blue,...
8
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1answer
122 views

What are the variables that control/influence the color of oranges(Citrus sinensis)?

I hear that Oranges cultivated in tropical areas of the world tend to be greener when ripe, is that correct? Even the same type of Orange differs in color if cultivated in California or Florida. I ...
8
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1answer
353 views

Was life less colorful before color vision evolved?

According to Wikipedia, we know that color-vision photopigments appeared in the common ancestors of tetrapods and fish at least 360 MY ago. Would life have been less colorful before the evolution of ...
8
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3answers
7k views

What determines the colors and patterns of a clam shell?

Earlier this week I was looking at some bivalve shells that had ornate patterns which ranged in color from a light orange-pink to a deep orange-red. Here is an image I found online that seems to be of ...
7
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1answer
2k views

Can cysteine alone change pigmentation?

According to this graph (from here): cysteine contributes to pheomelanogenesis, and having a high enough concentration of cysteine makes the shift towards pheomelanin instead of eumelanin. So my ...
7
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1answer
178 views

How do animals perform detailed active camouflage?

We often see videos of octopuses and chameleons changing their color to suit their surroundings. If it was a simple color change from white to red, it'd be understandable, but some of these animals ...
6
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1answer
827 views

Photosynthetic Pigments vs. Chloroplasts

What is the difference between Photosynthetic Pigments and Chloroplasts? I know plants have both but Prokaryotes (Bacteria and Archeae) only have the former.
6
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1answer
2k views

The colour of aquatic plants found deep under oceans

I have read that many aquatic plants found in deep oceans are red in colour, however, I do not understand why. As red is the color which gets the least scattered it should be the only light available ...
6
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1answer
1k 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?
6
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1answer
112 views

Why is there no symmetry in pigmentation when comparing people north and south of the equator?

If you are at the equator and start moving north, the further you travel, the lighter the skin of the indigenous peoples. Considering that we live on a ball, why do we not find the same traveling ...
5
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1answer
6k views

Is the Michael Jackson skin pigmentation disease realistic?

Quoting wikipedia: Jackson's skin had been a medium-brown color for the entire duration of his youth, but starting in the mid-1980s, it gradually grew paler. The change gained widespread media ...
5
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2answers
1k views

Why do most plants reflect green and others other colors?

I have read that chlorophyll absorbs red and blue. As shown in detail in the absorption spectra, chlorophyll absorbs light in the red (long wavelength) and the blue (short wavelength) regions of ...
5
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1answer
1k views

Are tongues red because they contain blood?

Many animals have red tongues, though not all of them - blue-tongued skinks and giraffes come to mind. Are they red because of the blood (and therefore haemoglobin) in them? It sounds plausible, but ...
5
votes
1answer
950 views

How does the color of henna fade?

Henna contain lawsone pigment that attaches to the proteins of the skin,hair,etc.But after a few weeks the color fades? How does the color fade? Is the pigment volatile or it is degraded by the body?...
5
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1answer
188 views

Why do dragonflies lose all of their coloration once they die?

At 06:43 in The Secrets of Nature video Sky Hunters, The World of the Dragonfly - The Secrets of Nature the narrator says: Scientists have been collecting ...
4
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1answer
2k 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 ...
4
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1answer
2k views

Skin color explanation?

I do not understand how skin color in humans work, even after taking a basic genetics course and reading some on wikipedia. From what I understand, skin is color based on multiple genes that control ...
4
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2answers
202 views

Why do some Brown Pelicans have orange or reddish parts on their bills?

I am doing research on Brown Pelicans and have photos/descriptions of the breeding and nonbreeding appearances of adults, esp. the California and eastern subspecies here on our southern Pacific, Gulf ...
4
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1answer
124 views

What makes drosophila eyes red? and is it stable?

I have Drosophila melanogaster which I am doing an eye pigmentation assay on in the future. To do this I will dissolve the heads, 10 of them removed from frozen whole flies, in acidified ethanol for ...
3
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2answers
23k views

How does a smoker's finger or mustache get yellowish by nicotine?

Tobacco use is the leading cause of preventable death around the world.$\ce{^1}$ The stain is considered as a "tell-tale" sign for identifying smokers. Multiple materials stated that it's due to tar ...
3
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1answer
897 views

Pigmentation in Jaundice

My textbook says that the yellow appearance of a jaundiced person is due to the accumulation of bile pigments in the skin. I am unable to understand why these pigments are not deposited in a healthy ...
3
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1answer
1k views

Difference between bacterial chlorophylls

I understand that bacterial chlorophylls are of the form a, b, c and d. But i read in my textbook about pigments like bacterio purpurin and bacterio viridin; are they a part of the 4 types of ...
3
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1answer
197 views

Are there animals which produce their own colour pigments`?

After discovering flamingos natural colour isn't red, pinkish as one naively may have assumed though, I looked into the matter more deeply. I also found out that many other animals do not produce the ...
2
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2answers
3k views

What is the cause of colours of nail

Why the nails are of white colour from bottom? then why they are pink and again white in the end?
2
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1answer
149 views

What pigment is responsible for the formation of blue skin color in some animals?

Not long ago I read about Vervet monkey. Here's picture: My question is what causes this blue coloration of the scrotum? I don't mean evolutionary need (e.g. attracting females), but what pigment or ...
2
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1answer
35k views

What would cause a single white eyelash?

I couldn't find a paper who could give me the explanation. Unfortunately, according to my search, it seems there are not many reported case, particularly for the younger population (<30). Would ...
2
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2answers
243 views

Can the colour of skin change with age

Can the colour of skin change with age? Can a dark skinned person become fair or vice versa? Can Melanocyte production vary?
2
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2answers
109 views

How can individual strands of coat hair have only a single color when considering codominance?

I understand how codominance works. We have two (or more) alleles for one gene, neither having dominance over the other. They are both expressed independently, which means that different phenotypes ...
2
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1answer
20k views

A strain of my hair has a grey spot in the middle, how is this possible? And why does it happen?

My hair is usually brown and black, I haven't dyed my hair for two years and if I had this would be strange. A strand of hair went from black(roots) grey (middle) then light brown(bottom). How does ...
2
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2answers
892 views

What mechanism suppresses melatonin release in humans?

I'm looking at melanopsin, a photo pigment in the human eye. One of its actions is to trigger suprachiasmatic nuclei SCN to suppress melatonin release. I'm interested in learning what is the exact ...
2
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1answer
2k views

How does boiling water release dyes from vegetables?

Why does boiling water always seem to release and become the colors of whatever vegetables I am boiling? For example, beet root and red cabbage both vividly color hot water. I'd assume it's ...
2
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0answers
50 views

What is the biggest structure in nature for structural coloration?

I'm interested in the actual sizes behind structural coloration: I find it fascinating and I think it may have a couple very nice applications. The problem is I couldn't find anything but vague ...
2
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0answers
2k views

Photosynthetic Absorption Spectrum - Pigment vs. Absorption Spectrum

This is a very confusing question to me that came up while I was studying photosynthesis. Halobacterium has a photosynthetic membrane that is colored purple. Its photosynthetic action spectrum is ...
2
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0answers
59 views

What's behind the amazing colour combinations in pests & insects?

What's behind the amazing colour combinations in pests & insects ? Do this colour combination signals any character/ poison of the pest/insect ?
1
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1answer
131 views

Do non-green flower colors have any functional interactions with the sun?

I always hear the pseudo-evolutionary claim "plants are green because they need to use red and blue light". If this premise to my question is true, What (if any) other functional relationship occur ...
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1answer
2k views

Is there any natural blue rose?

I had recently read an article that the possibility of having natural blue rose is extremely rare because of the absence of delphinidin in most roses. Are all blue roses just a product of cross-...