D. Oxygen
It refers to the pathway by which a chemical element is moved through both the abiotic and biotic compartment of an ecosystem.
Answer There resources include food, fuel, renewable energy, minerals, sand and gravel and tourism. Sustainable development and management of ocean resources is widely recognized by the international community and required for sustained human well-being.
Explanation:
The Calvin cycle is the cycle where in sugars are produced
in the chloroplast. Calvin cycle is also known as the Calvin-Benson cycle.
Calvin cycle has three stages this is fixation, reduction, and
regeneration. Calvin cycle is needed in
Photosynthesis.