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

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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 ...
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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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123 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 ...
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43 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 ...
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879 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 ...
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Polychromatic Fur considered against Monochromatic Hair

As I was gazing at a strand of fur that had shed from my cat, I was struck by the alternating bands of white, black, and tan. It seems that genetically coding for such an intricate coat pattern would ...
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103 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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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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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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118 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 ...
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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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1k 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 ...
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348 views

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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1answer
479 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 ...
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126 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 ...
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389 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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4k views

What causes the colors we see in eyes?

Genetics aside, what are the biochemical reasons the different colours of human irises? Also, related, how does eye colour change, particularly in childhood? (example: my eyes used to be blue, ...
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1answer
109 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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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.
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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 ...
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355 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 ...
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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 ...