Question

question 1 - 4
bacteria serve an important role in the cycling of carbon through the ecosystem. which of the following best describes why bacteria are essential to the carbon cycle? (sc 912 l 17 9)
they act as a reservoir for carbon by storing it in the form of dissolved organic carbon.
they break down carbon compounds in dead organisms and return the carbon to the soil and air.
they absorb carbon dioxide from the atmosphere and convert the carbon into glucose for organisms to consume.
they convert glucose from living organisms into energy and release the carbon in the form of carbon dioxide into the air

Explanation:

Bacteria are decomposers. Decomposers break down dead organisms (which contain carbon compounds). When they do this, they release carbon back to the soil (as nutrients) and to the air (as carbon - dioxide). Plants can take up carbon from the soil (in the form of nutrients) and from the air (carbon - dioxide for photosynthesis). This recycling of carbon is crucial for the carbon cycle.
Option 1: While some bacteria may store carbon, this is not the main role in the carbon cycle compared to decomposition.
Option 3: Plants (not bacteria) absorb carbon dioxide from the atmosphere and convert it to glucose via photosynthesis.
Option 4: While many organisms (not just bacteria) convert glucose to energy and release carbon - dioxide, the key role of bacteria in the carbon cycle is decomposition of dead matter.

Answer:

They break down carbon compounds in dead organisms and return the carbon to the soil and air.