Final answer:
The assertion that sunlight is not required for the Calvin Cycle in photosynthesis is true, as this stage uses chemical energy previously stored in ATP and NADPH from the light-dependent reactions to convert CO2 into carbohydrates.
Step-by-step explanation:
The statement that sunlight is not needed during the Calvin Cycle phase of photosynthesis is TRUE. The Calvin Cycle, also known as light-independent reactions or historically as 'dark reactions,' is the phase in photosynthesis where carbon dioxide is converted into carbohydrates without the need for sunlight. Although it is enabled by the light-dependent reactions that produce ATP and NADPH, the Calvin Cycle itself does not directly utilize light energy.
The Calvin Cycle can occur during both day and night, and involves a series of reactions that ultimately incorporate carbon atoms from carbon dioxide into sugars, such as glucose. The cycle takes place in the stroma of the chloroplast and utilizes the energy stored in ATP and the reducing power of NADPH (which are products of the light-dependent reactions) to drive the synthesis of carbohydrates. An important enzyme called ribulose biphosphate carboxylase (RuBisCO) plays a crucial role in this process.
Therefore, while the initial light-dependent reactions of photosynthesis require sunlight to generate ATP and NADPH, the subsequent Calvin Cycle proceeds without the need for sunlight, making good use of the chemical energy that has been stored.