Invertebrate Zoology

In animals, three main types of respiratory systems exist: respiration through the skin, respiration through the gills or respiration through internal air structures. Respiration through the skin, as in the Hydra, involves the passing of molecules into and out of the body via diffusion. Aquatic animals use gills, which are structures composed of tissues and blood vessels that extend from the body, for their respiration needs. Most terrestrial animals use internal air structures, such as lungs or tracheae, to respire. Cockroach, snail and earthworm has blood. 

Earthworms have no special respiratory organs. Gases are exchanged through the moist skin and capillaries, where the oxygen is picked up by the hemoglobin dissolved in the blood plasma and carbon dioxide is released.
The basic respiratory system of insects consists of a series of rigid tubes, called as tracheae.
In most of the fishes, the respiration takes place through gills.
The birds have lungs, air sacs and a syrinx and their respiration requires two cycles to move a volume of air.
Therefore, the correct answer is option A.

The constant number of cells or nuclei in individuals of a species or in parts of their bodies is known as eutely.

Because they are supposed to be associated with the function of excretion just like liver.

Externally the body wall of earthworm is covered by a thin non cellular cuticle below which lies the epidermis two muscle layers (circular and longitudinal) and innermost coelomic  epithelium.

In rabbits, sweat glands are not distributed over the entire body as they are in humans. They are notably present in the skin of the lips.

Alary muscles in cockroach are associated or connected with Heart. These muscles are attached to both dorsal and tergum diaphragm. They are triangular in shape where in the pointed end is attached to the tergum and other end is attached to dorsal diaphragm. The alary muscles are responsible for the circulation of blood. Hence option B is correct.

Cockroach has a 13 chambered longitudinal, thick, muscular and beaded heart. Each chamber receives oxygenated blood through slit like openings called ostia. 

The Bryozoa, also known as Polyzoa, Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. They are filter feeders that sieve food particles out of the water using a retractable lophophore a "crown" of tentacles lined with cilia. Most marine species live in tropical waters, but a few occur in oceanic trenches, and others are found in polar waters. 

Larval stages are common in the life cycles of many invertebrates (e.g., insects, mollusks) and some vertebrates (e.g., amphibians like frogs). Therefore, larvae occur in both groups.

Mosquitoes, ant, dung beetle, butterfly, moth, and cockroach all belong to class Insecta of phylum Arthropoda. They have one pair of antennae, three pairs of legs, and three body regions i.e., head, thorax, and abdomen. Thus, the correct answer is option D.

The mushroom gland is a large accessory male reproductive gland in the cockroach, which is whitish in colour and situated at the junction of vasa deferentia with the ejaculatory duct. It has a mass of glandular tubules of three kinds, the peripheral long tubules or utriculi majors, the central tubules are small short tubules or utriculi breviores and behind the short central tubules are some short but more bulbous tubules forming the seminal vesicles filled with sperms. 

Genital or brood pouch is a large boat-shaped structure whose floor is formed by the 7th sternite, roof and sides are formed by the 8th and 9th sternites. The genital pouch can be divided into a genital chamber into which vagina opens and an oothecal chamber where oothecae are formed. The genital chamber also receives the accessory reproductive glands. 

In female cockroaches, the secretions of the collateral glands form the hard protective capsule or ootheca around the fertilized eggs.

The genital pouch of female cockroach can be divided into two parts. The anterior smaller part containing the openings of female gonopore, pores of spermathecae and collateral glands is called genital chamber, while the larger posterior part in which ootheca is formed is called oothecal chamber or vestibulum. Oviduct doesn't open into the genital chamber.