[Campbell Biology P.243] The text describes how the cyanobacterium Chroococcidiopsis thermal... | Practice Question

The text describes how the cyanobacterium Chroococcidiopsis thermalis can acclimate to higher wavelengths of light. Cells that have acclimated use chlorophyll f, while those not acclimated still use chlorophyll a. What does this imply about the absorption properties of chlorophyll f compared to chlorophyll a?

  • A: Chlorophyll f is a more potent antioxidant than chlorophyll a, protecting cells from high light stress.
  • B: Chlorophyll f likely absorbs light at longer (higher) wavelengths than chlorophyll a, allowing the cyanobacterium to utilize light in conditions where chlorophyll a is less effective.
  • C: Chlorophyll f is involved in chemiosmosis, while chlorophyll a is solely for light absorption, indicating a division of labor.
  • D: Chlorophyll f is a precursor to chlorophyll a, and its presence indicates an immature photosynthetic system.

Explanation

The text states: 'In the last decade, researchers have identified two other forms of chlorophyll—chlorophyll d and chlorophyll f—that absorb higher wavelengths of light.' It then describes Chroococcidiopsis thermalis acclimating to 'higher wavelengths of light' by using chlorophyll f. This directly implies that chlorophyll f absorbs light at longer wavelengths compared to chlorophyll a, allowing the organism to thrive in different light environments.