Question

the single chlorophyll a makes the reaction centre which is different in both photosystems."

Answer 1

Photosynthetic bacteria that cannot produce oxygen have a single photosystem called BRC, bacterial reaction center. When photosystem II absorbs light, electrons in the reaction-center chlorophyll are excited to a higher energy level and are trapped by the primary electron acceptors.

Answer 2

the single chlorophyll a makes the reaction centre which is different in both photosystems."

Answer - :

Photosynthetic bacteria that cannot produce oxygen have a single photosystem called BRC, bacterial reaction center. When photosystem II absorbs light, electrons in the reaction-center chlorophyll are excited to a higher energy level and are trapped by the primary electron acceptors.