Bradley decided one day to run a marathon without any training. After ten minutes has elapsed and Bradley has run half a mile, he begins to get cramps in his thighs. He also breathing very rapidly. What is causing the cramps in bradley's legs.

answer: after carbon dioxide enters the leaf through stomata it moves into the mesophyll cells where photosynthesis occurs and glucose is constructed. respiration occurs when glucose (sugar produced during photosynthesis) combines with oxygen to produce useable cellular energy.

explanation:

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.