Answer:
680
Explanation:
When the P680 special pair of photosystem II absorbs energy, it enters an excited (high-energy) state. Excited P680 is a good electron donor and can transfer its excited electron to the primary electron acceptor, pheophytin.
Leukemia can be treated using human stem cells to attack and destroy cancer cells.
Answer:
The Arctic tern is a medium-sized bird around 33–36 cm (13–14 in) from the tip of its beak to the tip of its tail. The wingspan is 76–85 cm (30–33 in). The weight is 86–127 g (3.0–4.5 oz.).
Explanation: