Question

37 what gas is used by autotrophs & what gas is produced?
38 what starts the light reactions of plants and in what organelle do they occur?
39 flattened sacs in chloroplasts are known as ______ and are
40 ______ to each other.
41 thylakoid sacs in chloroplasts are called ______.
42 what gel - like solution surrounds the thylakoids inside the chloroplast?
43 what is the visible spectrum?
44 name the 7 colors that make up the visible spectrum.
45 what are pigments & what is their function in plants?
46 is red light reflected or absorbed by an object if the object appears red to your eyes?

Explanation:

Autotrophs, like plants, perform photosynthesis. In photosynthesis, they use carbon dioxide ($\ce{CO_2}$) and produce oxygen ($\ce{O_2}$). This is a key process in biology related to how autotrophs obtain energy and contribute to gas exchange in ecosystems.

Answer:

Autotrophs use carbon dioxide ($\ce{CO_2}$) and produce oxygen ($\ce{O_2}$).