The chemoreceptors of the tongue respond to monosaccharides (sugars), metal ions (salty tastes), alkaloids, and acids. which type of receptor do you think is the most sensitive? why?

The type of receptor that would be the most sensitive would be the receptors for alkaloids. They are sensitive in order for living organisms to be able to detect poisons from plants before they are being eaten. Without these receptors, many organism would be poisoned.