Final answer:
Mesophyll cells are responsible for absorbing carbon dioxide during the process of photosynthesis. The light-independent reactions occur in the stroma of chloroplasts within these cells, and photosynthates are transported through the plant in phloem sieve-tube elements.
Step-by-step explanation:
The cells that can absorb carbon dioxide in the process of photosynthesis are the mesophyll cells. These cells are located in the middle layer of the leaf and photosynthesis occurs here. The gas exchange of carbon dioxide and oxygen takes place through the stomata, which are openings regulated by guard cells on the underside of the leaf. However, it is the mesophyll cells that actually capture carbon dioxide and use it during the photosynthesis process.
The light-independent reactions of photosynthesis, also called the Calvin cycle, take place in the stroma of chloroplasts, which are found within the mesophyll cells. Additionally, it is in the mesophyll cells that the radioactive glucose would appear first after a pulse of radioactive carbon dioxide is provided to isolated leaves, indicating the primary site of photosynthesis.
Finally, the photosynthates, like sucrose produced during photosynthesis, are transported through the plant via the phloem sieve-tube elements (STEs) from the mesophyll cells where they are produced.