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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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Are there examples of Apis mellifera of different colors?

Re: my previos species-identification question, What species is this gray bee? I'm still curious: Are there any recorded/reported cases of either albino Apis mellifera, or at least with substantially ...
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Why is melanin black? [duplicate]

I understand that the function of melanin is to protect individuals from sunlight, and that people living in sun exposed areas are darker due to increased production of melanin. But why is the melanin ...
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Myoglobin in meat

When looking at the reason why some meat is white and the rest is red, I found out it is down to the levels of myoglobin as higher levels of myoglobin are found in "slow twitch" muscles. I have also ...
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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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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 ...
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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 ...
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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 ...
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How can myoglobin be responsible for the red color of meat if it is located in the cytoplasm?

How can myoglobin be responsible for the red color of meat if it is located in the cytoplasm, as the visible part of muscle cells is the membrane (at least as I believe)? Sources: https://en....
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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 ...
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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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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 ...
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How Dark skin protects humans in sunnier climates? [duplicate]

According to Physics, Black Body absorb all incoming light reflect nothing when compared to White body. This phenomenon is called Black-body radiation. So Melanin should turn your skin into white for ...
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What do animal cells store pigment in?

So I know plants store pigment in chloroplasts, chromoplasts, etc., but what do animal cells store pigment in? For example, is there like a chromoplast for melanin in the human body? I tried Googling ...
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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 ...
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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 ...
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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?...
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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 ...
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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 ...
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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 ...
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Why do redheads tend to sunburn more easily?

Reading Marion Roach's book on redheads she mentions visiting Rees lab where he shines UV light on her skin. Apparently this is an ongoing experiment of his regarding the propensity of redheads to ...
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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 ...
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Why do we see black when we close our eyelids? [closed]

Why do we usually see black when we close our eyelids assuming there is no strong light source outside? I realize we never really stop seeing as long as our eyes are healthy but based on assumption ...
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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 ...
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RNA interference and the former Petunias experiment >

I'm having problems trying to understand how RNA interference works. From what I understood, in simple terms there is this dsRNA which is fragmented into siRNA by the enzyme called Dicer, and those ...
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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 ...
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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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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 ...
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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 ...
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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 ...
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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?
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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 ...
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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 ...
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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 ...
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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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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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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 ...
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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 ...
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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 ...
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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 ...
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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 ?
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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 ...
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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?
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Why are human eye colours limited?

Related to the question What causes the colors we see in eyes?, I am wondering why human eyes are restricted in colour. Most common eye colours are blue, green and brown. Why not yellow, orange, ...
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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-...
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Why ducklings are yellow?

Why ducklings are yellow, what the evolutionary background for this? How could it help to survive? UPDATE I agree with comment below, I did remember then that ducks are wild animals too (when I ...
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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 ...
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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 ...
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697 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 ...
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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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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,...