In the alimentary canal of a cockroach, as a food bolus travels strictly through the foregut starting from the oesophagus, which of the following correctly represents the chronological sequence of primary functions it encounters?

Step-by-step solution

In the foregut of a cockroach, the oesophagus is a short tubular structure that primarily serves for the passage of food. It opens into a sac-like structure called the crop, which is used for the temporary storage of food. The crop is followed by the gizzard (proventriculus), which has an outer layer of thick circular muscles and a thick inner cuticle forming six highly chitinous plates called teeth. These teeth are used for the mechanical grinding of food particles. Therefore, the correct functional sequence is Pa