Tag: zoology

1. Testes lie dorsolaterally in the 4th and 5th abdominal segments, and they are the region of sperm production.
   2. Vas deferens are a pair of ducts arising from the testis as very thin whitish tubes, they continue posterioventrally beneath the rectum. They unite at a short distance into the ejaculatory duct.
   3. Mushroom gland is a large accessory reproductive gland, whitish in colour and situated at the junction of vasa deferentia with the ejaculatory duct. It has a mass of glandular tubules of two kinds; utriculi majores and utriculi breviores.
   4. The sperms produced from testes, while the cockroach is still young, are brought by the vasa deferentia into the seminal vesicles for storage. The sperms in the seminal vesicles are glued together in the form of bundles called spermatophores. 
   So, the correct option is 'Seminal vesicles'.

In male cockroach, from the sides of the 9th sternum, there arises a paired, small unjointed outgrowths called anal styles. These structures are sensitive to touch.These are absent in female cockroach. Nervous system is located ventrally. There are 100-150 Malpighian tubules. Grinding of food is carried our by mouth parts and gizzard.

1. The body of female cockroach is relatively larger than the male.

2. The abdomen of female cockroach is boat-shaped and the last segment is blunt.

3. The wings of female cockroach are smaller than that of the males and extend up to the tip of the abdomen.

4. The antennae are relatively larger than that of the males.

5. Only a pair of anal cerci is present in of female cockroach.

6. The sternum of mesothorax is bifid.

So the correct option is 'anal styles'.

All cockroaches develop by completing a life cycle consisting of three distinct stages: egg, nymph, and adult.

(A) Phallomere - The external genitalia

Sexual dimorphism is the differences in appearance between males and females of the same species. The adult males have full wings covering their body, while females have only tiny wing stubs, their tegmina (forewings) being around a fourth of their body length.
Therefore, the correct answer is option D.

Sex pheromones are released by an organism to attract an individual for mating. Cockroaches form the dominance hierarchies based on pheromone badges, while females use the same pheromone for male choice.
Therefore, the correct answer is option B.

The intersegmental membrane between the 5th and 6th terga is depressed on either side of the stink gland. These glands are present in both male and female cockroaches and produce a secretion with a characteristic odour. The secretion is a pheromone which helps to attract the opposite sex.
Therefore, the correct answer is option C.

Eggs of cockroach are centrolecithal. During cytokinesis, centrolecithal zygotes undergo meroblastic cleavage, where the cleavage plane extends only to the accumulated yolk and is superficial. This is due to the large dense yolk found within centrolecithal eggs and helps in delayed embryonic development.