a. Sweet, bitter, umami, sour.

Here’s why:

Transient Receptor Potential channels involved in the detection of various sensory stimuli, including taste.

Different TRP channels play role in detecting different taste qualities:

Sweet, bitter, and umami rely on TRP channels for their detection through specific receptors.

Sour taste, though primarily detected by proton-sensitive ion channels, can also involve TRP channels in some aspects.

Salty taste mainly involves ion channels like the ENaC (Epithelial Sodium Channel), not TRP channels.

If all TRP channels are knocked out in the mice, they would not be able to detect sweet, bitter, umami, or sour tastes properly, as these rely on TRP channels. Salty taste detection would still be possible, as it doesn't rely on TRP channels.

Learn: Part 3—> M101A