Final answer:
A mutation hindering the activation of chloroplast's light-independent enzymes, such as RuBisCO, would likely lead to decreased enzyme activity, impairing the Calvin cycle and photosynthesis, and affecting the plant's ability to synthesize sugars.
Correct option is c) Complete cessation of enzyme activity
Step-by-step explanation:
If a chloroplast's light-independent enzymes developed a mutation hindering activation in response to light, the likely outcome would be a decrease in enzyme activity. In a light-independent reaction, enzymes play a critical role in catalyzing reactions that do not require light but are part of the photosynthesis process. Specifically, if enzymes like RuBisCO were affected, the Calvin cycle would not proceed efficiently, leading to a reduced synthesis of G3P and other sugars that are vital for the plant's energy and biomass.
When an enzyme is not functioning correctly in a chemical reaction, the reaction either stops or proceeds more slowly. For example, if RuBisCO is affected, it would result directly in reduced carbon fixation. Furthermore, if a plant mutation eliminated the photosystem II complex, the light-dependent reactions would not occur properly, affecting the end products of photosynthesis. Lastly, while cells in a light-restricted environment might survive if they develop an enzyme to synthesize the required molecule D, a mutation inactivating an essential coenzyme like coenzyme A would have severe consequences for a cell's metabolic processes.