Question

In both sexes of cockroach, a pair of jointed filamentous structures called anal cerci are present on

• A. 5th segment
• B. 10th segment
• C. 8th and 9th segment
• D. 11th segment

Answer 1

The Correct Option is B

In the anatomy of a cockroach, the anal cerci are crucial sensory organs located on the posterior end of the abdomen. These are bilateral appendages, meaning they come in pairs, situated in both male and female cockroaches. Their primary function is to detect vibrations and movements, aiding the cockroach in responding to its environment swiftly, such as when evading predators. Now, let us identify where these anal cerci are attached:

The body structure of a cockroach consists of three primary segments: the head, thorax, and abdomen. The abdomen itself is divided into 11 segments, numbered successively from front to back. Each segment plays a distinct role in the cockroach's overall anatomy and function. The correct placement of the anal cerci is on the abdomen’s 10th segment. This location is crucial for maximizing the sensitivity to environmental stimuli, enhancing the survival mechanism for sudden ground vibrations and potential threats.

Thus, the answer is that in both sexes of the cockroach, the anal cerci are present on the 10th segment of the abdomen.

Segment	Structure
5th segment	Not applicable
8th and 9th segment	Not applicable
10th segment	Anal cerci present
11th segment	Not applicable