Question

The anal styles in cockroaches are present on
(a)tenth tergite of female
(b)tenth tergite of male
(c)ninth sternite of male
(d)tenth sternite of male

Answer 1

Hint: Short, thread-like paired structures called anal styles are present only in males and is absent in females. The 10th segment bears a pair of jointed filamentous structures called anal cerci in both the sexes.

Complete answer:
Cockroaches exhibit sexual dimorphism. The abdomen of a cockroach consists of 10 segments in both male and female cockroaches. In females, the sclerites of the 8th and 9th segments are overlapped by the sclerite of the 7th segment. The 7th sclerite is boat-shaped. It forms a brood pouch together with the 8th and 9th sterna. In males, only the 8th sternum is overlapped by the 7th. In both the male and female, a pair of filamentous jointed structures called the anal of cerci are present on the 10th segment. In males, the 9th segment bears a pair of short, thread-like anal styles, ventral to the cerci.

Additional Information: -Cockroaches belong to Phylum Arthropoda and Class Insecta. The animal is notochordal and found in warm and damp places.
-The body is narrow, elongated, and is bilaterally symmetrical and covered by a chitinous exoskeleton.
-Body of a cockroach is divided into three parts as head, thorax, and abdomen. The Head is attached to the thorax by a short neck. It has compound eyes, antennae, and mouthparts. mouthparts are of chewing type.
-The thorax is divisible into prothorax, mesothorax, and metathorax. It bears three pairs of legs on the ventral side and two pairs of wings on the dorsal side.
-The alimentary canal is divisible into foregut, midgut, and hindgut.
-The excretory system consists of malpighian tubules. The animal is uricotelic, i.e. excretes uric acid.
-The nervous system is spread throughout the body. It consists of a series of fused, segmentally arranged ganglia, joined by longitudinal connectives on the ventral side.
So the correct answer is ‘ ninth sternite of male’.

Note: Each segment of the exoskeleton is called Sclerite. Male cockroaches have anal styles on the 9th sternum, but no brood pouch. The female cockroach doesn’t have anal styles but has a brood.