Question

Which one of the following is the true description about an animal concerned?

• A. Earthworm - The alimentary canal consists of a sequence of pharynx, oesophagus, stomach, gizzard and intestine
• B. Frog - Body divisible into three regions-head, neck and trunk
• C. Rat- Left kidney is slightly higher in position than the right one
• D. Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen)

Answer 1

Answer: (D)

The respiratory system of cockroach consists of tracheae, tracheoles and spiracles. The main tracheal trunks open to exterior on body surface through $10$ pairs of segmentally arranged spiracles. Two pair of spiracles are thoracic (one between pro and mesothorax and other between meso and metathorax). Eight pairs of spiracle are abdominal (one pair in each of the first eight abdominal segments).
Alimentary canal of earthworm is complete and functionally regioned into buccal chamber, pharynx, oesophagus, gizzard, stomach and intestine.