Use the information you learned about carbon-based molecules to explain a human's need to participate in the biogeochemical cycles.

Human releases carbon dioxide during respiration and also certain activities performed by him  lead to generation of carbon which at some stage become the part of biogeochemical cycle.

Explanation:

Carbon is an elementary part of all living beings and thus is found in almost all the living organism and human as an evolved species has the ability to take in oxygen and release carbon dioxide.  

This released carbon dioxide enters into the biogeochemical cycles (predominantly the carbon cycle) and get converted into useful form again after going through a cyclical process via various biotic and abiotic stages.  

Also certain human activities like burning of fossil fuels, wood etc also releases carbon based product such as carbon di-oxide, carbon mono-oxide etc, . These products from unnatural process also become part of biogeochemical cycle.  

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.