Lipids as pigments in plants and bird feathers.

Birds acquire the pigments that color their feathers red or yellow by eating plant materials that contain carotenoid pigments, such as canthaxanthin and zeaxanthin.

The differences in pigmentation between male and female birds are the result of differences in intestinal uptake and processing of carotenoids.

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Some other biologically active isoprenoid compounds or derivatives.

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#Section 2: General Biology

β-Carotene is the precursor of vitamin A1.
Oxidation at C-15 converts retinol to the aldehyde, retinal, and further oxidation produces retinoic acid, a hormone that regulates gene expression. 

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Steroids derived from cholesterol.

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Arachidonic acid and some eicosanoid derivatives.

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#Section 2: General Biology