Concept:The main metabolic waste product excreted by plants is carbon dioxide, produced during respiration.
Explanation:Plants produce several metabolic wastes, including carbon dioxide, oxygen, and water.
During aerobic respiration, glucose is broken down to release energy, forming carbon dioxide and water as by-products.
This gas diffuses out of the plant mainly through the stomatal pores on leaves.
Oxygen is released during photosynthesis, but it is used for respiration and is not the chief excretory waste.
Alkaloids and mucilage are secondary products or protective substances, not primary excretory wastes.
Hence, in plant metabolism, the most important excretory product is carbon dioxide, written as
CO2.
Answer:The main excretory product is carbon(iv)oxide,
CO2.
Correct option: C.