AP BIOLOGY

Detailed explanation-1: -Carbon dioxide (CO2) is a product of respiration and not photosynthesis.

Detailed explanation-2: -The dark reaction occurs outside of the thylakoids. In this reaction, the energy from ATP and NADPH are used to fix carbon dioxide (CO2). So NADH is not a product of the light reaction of photosynthesis.

Detailed explanation-3: -The correct answer is OPTION 4: Carbon Dioxide.

Detailed explanation-4: -The products of photosynthesis are glucose and oxygen. Although the hydrogen atoms from the water molecules are used in the photosynthesis reactions, the oxygen molecules are released as oxygen gas (O2).

Detailed explanation-5: -The by-Product of Photosynthesis is (1) CO2 (2) H20 (3) Glucose (4) O2.