Answer:
homeostasis.
Explanation:
Homeostasis is the process whereby living systems maintain a stable internal environment despite changes in environmental conditions. Plants, like every other living organisms also perform this process to keep their internal environment in a stable state.
According to the question, some plants were exposed to ammonium nitrate, which serves as a nutrient, and 16 hours of sunlight needed for photosynthesis to take place. The plants exposed to ammonium nitrate and 16 hours sunlight grew taller because they had access to nutrients needed to bring about the process of photosynthesis, which provides the plant with energy source (Glucose).
The uptake of nutrients like ammonium nitrate by the plants is done in order to maintain a homeostatic internal environment. Without nutrients, which is the purpose of the ammonium nitrate, plants cannot grow. Hence, the plants exposed to ammonium nitrate, take it in to keep their internal environment functioning.