Step 1: Understanding the Problem:
The frog has a well-developed, complete digestive system adapted to its carnivorous diet, featuring specific anatomical variations compared to humans.
Step 2: Approach and Formula:
Review the anatomical morphology of the frog's digestive tract, particularly analyzing the spatial constraints of the amphibian body plan.
Step 3: Detailed Explanation:
- Statement (1): Frogs possess a muscular, highly sticky, bilobed tongue attached at the front of the mouth, explicitly adapted to flick out and capture insect prey. (True).
- Statement (3): Similar to humans, the frog's liver secretes bile juice, which is concentrated and temporarily stored in the gall bladder. (True).
- Statement (4): Post-digestion, the remaining undigested solid waste enters the rectum and is eventually expelled out of the body through a common exit chamber called the cloaca. (True).
- Statement (2): Frogs essentially lack a true neck. Because of this compressed anatomy, the distance between the mouth and the stomach is extremely short. Consequently, the oesophagus is a very short tube, not a "long tube" as the statement claims.
Step 4: Final Answer:
The incorrect statement is (2).