[Campbell Biology P.834] Considering the "MAKE CONNECTIONS" prompt, how would the gas exchan... | Practice Question

Considering the "MAKE CONNECTIONS" prompt, how would the gas exchange processes described for Figure 36.2 primarily change in a vascular plant at night ?

  • A: Leaves would primarily take in O2 and release CO2, while root cell gas exchange would remain the same.
  • B: Both leaves and roots would cease all gas exchange.
  • C: Leaves would continue to take in CO2 and release O2, but at a reduced rate.
  • D: Root cells would switch to taking in CO2 and releasing O2.

Explanation

At night, photosynthesis which requires light largely ceases. Therefore, leaves will no longer take in CO2 or release O2 from photosynthesis. They will, however, continue to respire, meaning they will take in O2 and release CO2. Root cells only perform cellular respiration, so their gas exchange O2 in, CO2 out remains the same day and night.