Question

What is true about gonapophysis of a cockroach?
(a)Three in each sex
(b)Six in each sex
(c)Three in female and six in female
(d)Six in female and three in male

Answer 1

Hint: Cockroaches are pests found in unhygienic places. Gonapophysis (singular) is a chitinous asymmetrical sheet-like structure found in the anal region of cockroaches, in the female, the number of gonapophyses is twice the number of gonapophyses in males.

Complete answer:
Gonapophysis makes the external genitalia of the cockroach and plays an important role by assisting in the reproduction process.
A male cockroach has three gonapophyses and the female cockroach has six gonapophyses.
In male cockroach –
Three chitinous structure called phallomere or male gonapophysis make up the external genitalia of the cockroach, consisting of
-Right Phallomere
-Left Phallomere
-Ventral Phallomere
These phallomere assists in opening the gynatrium of the female cockroaches.
In Female cockroach-
Six gonapophyses make up the external genitalia.
The external genitalia consists of an ovipositor formed by two gonapophyses. The ovipositor lies above and behind the gonopore.
The other gonapophysis pairs combine to form anterior and posterior gonapophyses.
So, the correct answer is, ‘ Six in female and three in male.’

Note: Difference between a male and female cockroach
-Size: Female cockroaches are bigger than male cockroaches.
-The shape of the abdomen; male cockroaches’ abdomen is slender shaped while female cockroaches' abdomen is blunt or boat-shaped.
-Wings-the wings of the male cockroach are larger than the female cockroach.
-Antenna – Antennae of the male cockroach are smaller than the female.
-Testes are present on the 4th and 6th segments of the abdomen of male cockroaches while ovaries are present on the 2nd and 6th segments of the abdomen of female cockroaches.