Halobacterium has a photosynthetic membrane that appears purple. its photosynthetic action spectrum is theinverse of the action spectrum for green plants. (that is, the halobacterium action spectrum has a peak where thegreen plant action spectrum has a trough.) what wavelengths of light do the halobacterium photosyntheticpigments absorb? a. red and yellowb. blue and redc. red and greend. blue, green, and rede. green and yellow

E. green and yellow

Explanation:

Starting from lower to higher wavelength blue light comes first followed by green, yellow and finally red. Hence blue and red lie at wavelength extremes whereas green and yellow fall in middle. Action spectrum displays the rate of photosynthesis at each of these wavelengths of light.

Plant photosynthetic pigments absorb blue and red light hence photosynthesis occurs at these wavelengths more. So when action spectra for a plant is being plotted, two peaks are observed, one at blue wavelength and one at red. Green and yellow light is not absorbed by plants and reflected back hence a trough is formed at this wavelength zone in center.

It is given that halobacterium shows opposite action spectrum to plants which means that photosynthesis rate is more at the center green-yellow zone so a peak is formed at the center. Thus, halobacterium photosynthetic pigments absorb green and yellow light and reflect red and blue light which makes it appear purple.  

multiply it by 5 in order for you to understand i cant give an exact answer.