This question is incomplete. The complete question is:
A green plant absorbs a toxic substance that completely blocks the production of ATP. How would this most likely affect the dark reactions?
A - The dark reactions would stop happening.
B - The dark reactions would produce more NADPH
C - The dark reactions would continue to produce oxygen
D - The dark reactions would produce more carbon dioxide
Answer:
The correct answer is option A - The dark reactions would stop happening.
Explanation:
During the process of photosynthesis there is a part that needs sunlight and a part that does not.
The part that does not need light is the so-called dark reaction, which happens inside the part of the plants that contains chlorophyll, and is called chloroplast.
Plants are going to make sugars that are going to be useful for generating nutrients and other vital substances.
While we said that the dark reaction does not use sunlight, it depends on it for the creation of ATP, (which provides almost all cellular energy) and NADPH.
Once the ATP is created during the dark reaction, that is also called the Calvin cycle, carbon dioxide wastes must be converted into carbohydrates. Then ATP and NADPH, which were already formed thanks to sunlight, will have to be combined with water and discarded carbon dioxide to produce glucose.
Therefore, if ATP does not exist, there is also no dark reaction. So the correct answer is option A.
