Question

question 33 (1 point)
how are the two steps of photosynthesis connected?
o a the light - independent reactions release oxygen for the light - dependent reactions
b the two steps occur at completely separate times
o c the light - dependent reactions make glucose for the light - independent reactions
d the light - dependent reactions produce atp and nadph, which power the light - independent reactions

Explanation:

Photosynthesis has two main steps: light - dependent reactions and light - independent reactions (Calvin cycle). Light - dependent reactions occur in the thylakoid membranes and produce ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These energy - rich molecules are then used in the light - independent reactions (which occur in the stroma) to power the conversion of carbon dioxide into glucose.

Now let's analyze each option:

• Option a: The light - independent reactions do not release oxygen. Oxygen is released in the light - dependent reactions (from the splitting of water).
• Option b: The two steps (light - dependent and light - independent) are not completely separate in time. They are part of the same overall process of photosynthesis.
• Option c: The light - dependent reactions do not make glucose. Glucose is made in the light - independent reactions.
• Option d: This is correct as the light - dependent reactions produce ATP and NADPH which are essential for the light - independent reactions.

Answer:

d. The light - dependent reactions produce ATP and NADPH, which power the light - independent reactions.