Question

In cockroach
A) Ejaculatory ducts in phallic gland
B) Phallic gland store sperms
C) Vas deferens opens in phallic gland
D) Phallic gland opens in phallomere.

Answer 1

The cockroaches belong to the class Insecta and phylum Arthropoda. They are nocturnal omnivores types of insects that live mostly in damp places all over the world.

Complete answer:
The cockroach has a segmented body that is divided into three different parts- head, thorax, and abdomen. The male reproductive system of Periplaneta consists of a pair of testes, a pair of vasa deferentia, and ejaculatory duct, a pair of seminal vesicles, a mushroom-shaped gland, and a phallic gland. Let us analyse each option to find out the correct answer.

Option A: The ejaculatory duct is a muscular tube that extends posteriorly and opens at the gonopore or the male genital pore.Therefore, this is an incorrect option.
Option B: A phallic or the conglobate gland is also associated with the male reproductive system of the Periplaneta. The duct of this gland opens near the gonopore. Sperms are stored in the seminal vesicles. Therefore, this is an incorrect option.
Option C: A thin duct called vas deferens begins from the posterior end of each testis. The two vasa deferentia run backward and open into a wide median duct, the ductus ejaculators in the seventh segment. Therefore, this is an incorrect option.
Option D: A phallic or the conglobate gland is also associated with the male reproductive system of the Periplaneta. The duct of this gland opens near the gonopore. Its function is still not known. It is a large elongate sac-like structure that lies beneath the mushroom gland and ejaculatory duct. Phallic gland opens in the left phallomere. Therefore, this is the correct option.

Hence the correct answer is option ‘D’.

Note: It is to be noted that the mature sperms are transported by vas deferens into the seminal vesicles for storage. The male reproductive system of cockroaches consists of a pair of testes which is present in the fourth and sixth segments of the abdomen.