What colors are reflected by chloroplasts?

What colors are reflected by chloroplasts?

• A. Red and blue
• B. Green and yellow
• C. Green only
• D. Yellow only

Answer: (B)

Chloroplasts show colors based on the pigments they contain. The main pigment, chlorophyll, absorbs red and blue light and reflects green, which is why chloroplast-rich tissue often looks green. But chloroplasts also have carotenoids (like xanthophylls and carotenes) that reflect yellow to orange light and absorb blue-green. Because multiple pigments are present, the light that is reflected can include both green and yellow wavelengths, especially depending on the relative amounts of pigments and the light conditions. Red and blue light are largely absorbed rather than reflected, so they don’t determine the color we see. In practice, green is common, but yellow can also be reflected due to carotenoids, making green and yellow the colors associated with chloroplast reflections.

Chloroplasts show colors based on the pigments they contain. The main pigment, chlorophyll, absorbs red and blue light and reflects green, which is why chloroplast-rich tissue often looks green. But chloroplasts also have carotenoids (like xanthophylls and carotenes) that reflect yellow to orange light and absorb blue-green. Because multiple pigments are present, the light that is reflected can include both green and yellow wavelengths, especially depending on the relative amounts of pigments and the light conditions. Red and blue light are largely absorbed rather than reflected, so they don’t determine the color we see. In practice, green is common, but yellow can also be reflected due to carotenoids, making green and yellow the colors associated with chloroplast reflections.