What process releases oxygen into a food web ecosystem

photosynthesis

Explanation:

the process of photosynthesis converts light and energy into the stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.

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

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]