Anus in Cockroaches occurs onA. Tenth sternumB. Dorsal surface of 10th tergumC. Ventral surface of 10th tergumD. Ninth sternum

The correct answer is B. Dorsal surface of 10th tergum.
In cockroaches, the anus is located on the dorsal surface of the 10th tergum, which is the last segment of the abdomen. The tergum refers to the dorsal (upper) part of each abdominal segment, while the sternum refers to the ventral (lower) part.
Key Points:
1. Location of the Anus:
o The anus in cockroaches is the opening of the digestive tract through which waste is expelled.
o It is situated dorsally on the last segment (10th tergum) of the abdomen.
2. Functions:
o It serves as the exit point for the undigested material after the digestive process is complete.
3. Significance of the 10th Tergum:
o The 10th tergum also plays a role in supporting other external structures like the anal cerci, which are paired sensory structures.
Why Not the Other Options?
• A. Tenth sternum: This is the ventral part and does not house the anus.
• C. Ventral surface of 10th tergum: The anus is located on the dorsal surface, not the ventral.
• D. Ninth sternum: This is part of the ventral structure but is not associated with the anus.
Thus, the anus of a cockroach is located on the dorsal surface of the 10th tergum.