Number of Visible Sternum in Female Cockroach

The sternum is the ventral (underside) part of the exoskeleton of an insect. It consists of a series of segments called sternites. The number and arrangement of sternites can vary among different insect species. In the case of female cockroaches, they typically have a certain number of visible sternum segments at their abdomen.

Answer: C) 8

Explanation:

1. Cockroach Abdomen Structure
The abdomen of a cockroach is composed of ten segments, numbered from 1 to 10. The segments are covered by tough exoskeletal plates called tergites and sternites. The tergites are located dorsally (on the upper side), while the sternites are located ventrally (on the underside).

2. Identification of Sternum
To determine the number of visible sternum segments in a female cockroach, we need to identify the sternum plates. These sternum plates are more flexible and can be seen from the ventral view. They are located between the legs of the cockroach.

3. Counting the Sternum Segments
In a female cockroach, there are eight visible sternum segments in the abdomen. These segments are numbered from 3 to 10. The sternum segments 1 and 2 are not visible as they are fused with the head and thorax.

4. Arrangement of Sternum Segments
The sternum segments in a female cockroach are arranged as follows:
- The third sternum segment is located between the second and third pair of legs.
- The fourth sternum segment is located between the third and fourth pair of legs.
- The fifth sternum segment is located between the fourth and fifth pair of legs.
- The sixth sternum segment is located between the fifth and sixth pair of legs.
- The seventh sternum segment is located between the sixth and seventh pair of legs.
- The eighth sternum segment is located between the seventh and eighth pair of legs.
- The ninth sternum segment is located between the eighth and ninth pair of legs.
- The tenth sternum segment is located between the ninth and tenth pair of legs.

Conclusion:
In summary, a female cockroach has eight visible sternum segments in its abdomen, numbered from 3 to 10. The sternum segments provide flexibility and support to the cockroach's abdomen, allowing it to move and perform various functions.

Here, Answer is B)7...In cockroach,in case of sterna:-in female - 7th sterna is visible....in male - 9th sterna is visible....and ,in case of terga:-in female - both 8th & 9th terga are not visible....in male - 8th terga is not visible...