For question 1, the correct answer is carbon dioxide.
The light-independent reactions, also known as dark reactions of photosynthesis, refer to the chemical activities, which transform carbon dioxide and other components into glucose. These reactions take place in the stroma, the fluid-filled region of a chloroplast external to the thylakoid membranes.
The answer to the 2nd question is photosynthesis and cellular respiration.
Water is utilized at the time of electron transport chain in photosynthesis. On the other hand, during the process of cellular respiration, both water and carbon dioxide is formed as a waste product.