AP BIOLOGY

PHOTOSYNTHESIS

LIGHT DEPENDENT REACTIONS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Chlorophyll absorbs ____ and ____ light from the light.
A
purple and green
B
red and blue
C
black and orange
D
yellow and green
Explanation: 

Detailed explanation-1: -As shown in detail in the absorption spectra, chlorophyll absorbs light in the red (long wavelength) and the blue (short wavelength) regions of the visible light spectrum. Green light is not absorbed but reflected, making the plant appear green. Chlorophyll is found in the chloroplasts of plants.

Detailed explanation-2: -In plants, chlorophyll a and chlorophyll b are the main photosynthetic pigments. Chlorophyll molecules absorb blue and red wavelengths, as shown by the peaks in the absorption spectra above.

Detailed explanation-3: -In the case of chlorophyll a the maximal absorption in the red region is at 642 nm and in the blue region at 372 nm; for chlorophyll b the values are 626 nm and 392 nm, respectively.

Detailed explanation-4: -The chlorophyll molecule actually absorbs red and blue light and reflects green light, and the reason it absorbs certain colors of light and reflect other colors is because of its chemical structure. Many things with colors, such as paints, have colors because they have molecules with rings of carbon atoms.

Detailed explanation-5: -Chlorophyll a is the most abundant pigment in plants. Chlorophyll a absorbs light mostly 430nm (blue) and 662nm (red) wavelength light. It reflects green light so it appears green to us. Chlorophyll b molecule has a similar structure to that of chlorophyll a.

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