Each eye is composed of a large number of independent visual units called ommatidia which are connected to the optic nerve. These small images are combined in the brain to form a complete image of the object that is made of small dots or mosaic of dots and hence it is called mosaic vision. Vision of cockroach is Mosaic.

The ocelli are paired circular areas one on each side of the eye, near the base of the antennae. Each area acts as a simple eye and is responsible for detecting light. Ocelli or fenestrae of cockroach take part in perception of light.

The utricular gland is a large whitish gland which is made up of two kinds of glandular tubules.

Ecdysone is a steroidal prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. The steroid ecdysone secreted from the Y-organ stimulates molting. After it is released into the blood, ecdysone is converted to a 20-hydroxyecdysone, which is the active molting hormone. Secretion of ecdysone is blocked by a neurohormone called molt-inhibiting hormone, produced by the eyestalk complex.

Frog is a stenohygrous animal which is also known as Amphibious animal. It lives in or near freshwater bodies, like ponds, lakes, ditches, marshes and even slow running waters. Frog tolerant to a broad range of atmospheric moisture. 

The respiratory system consists of a network of trachea ,that open through 10 pairs of small holes called spiracles present on the lateral side of the body. Thin branching tubes carry oxygen from the air to all parts. The opening of the spiracles is regulated by the sphincters. 

Haemoglobin is absent in cockroach,the respiratory system consists of a network of trachea, that open through 10 pairs of small holes called spiracles present on the lateral side of the body. Thin branching tubes carry oxygen from the air to all the parts. The opening of the spiracles is regulated by the sphincters. Exchange of gases takes place at the tracheoles by diffusion.

When an immature insect has grown sufficiently to require a larger exoskeleton, sensory input from the body activates certain neurosecretory cells in the brain. These neurons respond by secreting brain hormone which triggers the corpora cardiaca to release their store of prothoracicotropic hormone (PTTH) into the circulatory system. This sudden "pulse" of PTTH stimulates the prothoracic glands to secrete molting hormone.

Dorsal diaphragm consists of connective tissue with associated muscles which are called alary muscles. In cockroaches, they resemble wings projecting laterally from the dorsal vessel of each abdominal segment. It is the Alary muscles that help in blood circulation. The alary muscles are associated with all the thirteen chambers of cockroach's heart on either side of it. The alternate contraction and relaxation of these muscles help to pump the blood.

In cockroach, the respiratory system consists of a network of the trachea, that open through 10 pairs of small holes called spiracles present on the lateral side of the body. Thin branching tubes carry oxygen from the air to all parts. The openings of the spiracles are regulated by the sphincters. Exchange of gases takes place at the tracheoles by diffusion.

The first body segment is called the peristomium (buccal segment) which contains the mouth. In a mature worm, segments 14, 15 and 16 segments are covered by a prominent dark band of glandular tissue called clitellum. Thus the body is divisible into three prominent regions - preclitellar, clitellar and postclitellar segments.

Male cockroaches have colorless blood and female cockroaches have blood in orange color. This is due to the absence of haemoglobin in their blood. Cockroaches use a series of tubes known as trachea for respiration process. Oxygen reaches through the tissues with the help of tracheoles. 

The coelomic fluid is generally secreted by the earthworms for maintaining moisture to help their physiological activities such as respiration and burrowing activities. It consists of a watery matrix, the plasma and a large number of coelomocytes.  The composition of the fluid varies markedly depending on its source and is regulated more or less precisely by homeostasis.

A pair of short conical intestinal caecae project in the intestine on the 26th segment. The characteristic feature of the intestine after 26th segment except for the last 23rd -25th segments is the presence of an internal median fold of dorsal wall called typhosole. This increases the effective area of absorption in the intestine. The alimentary canal opens to the exterior by a small rounded aperture  alimentary canal known as anus.

Pharyngeal nephridia lie in three paired tufts, one on either side of the anterior region of the alimentary canal in the segments 4th, 5th, and 6th. The tufts of pharyngeal nephridia also contain blood glands.

In thorax of cockroach, bodies have three primary regions are the head, the thorax, and the abdomen. They have three pairs of jointed legs, one pair of antennae and a rigid exoskeleton.  Most cockroaches have three joints on each leg, which means they have 18 knees. The metathoracic legs are located at the back of the thorax and they help the insect to move forward.

The oriental cockroach known as Blatta orientalis, also known as the waterbug or black beetle, is a large species of cockroach, adult males being 18–29 mm and adult females being 20–27 mm. It is dark brown or black in color and has a glossy body. Oriental cockroaches tend to travel somewhat more slowly than other species. 

Chloragogen cells store glycogen and neutralize toxins, are yellowish in color due to the presence of yellow granules called chloragosomes and are present in the coelomic fluid of some annelids. It is similar to the liver of a vertebrate. They take part in the deamination of amino acids and synthesis of urea. Silicates taken in along with food are deposited in the chloragogen cells.

Chloragogen cells, also called as y cells are cells in annelids that function similarly to the liver in vertebrates. The cells store glycogen and neutralize toxins, are yellowish in colour due to the presence of yellow granules called chloragosomes and are present in coelomic fluid of some annelids.

Blood glands are present on the 4th,5th and 6th segments. They produce blood cells and haemoglobin which is dissolved in blood plasma. Blood cells are phagocytic in nature. The blood vascular system of Pheretima is of closed type. It consists of the blood vessels, hearts, loops, capillaries, and the blood glands. Hence blood glands are present in 4th,5th and 6th segments.

In Cockroach, there are three pairs of thoracic legs on the ventral side. Each leg is five jointed or segmented. The upper portion of the leg, called the coxa, attaches the leg to the thorax. The other parts of the leg approximate parts of a human leg: The trochanter acts like a knee and lets the roach bend its leg. The femur and tibia resemble thigh and shin bones.

Cellulase occurs in the American cockroach and originates in two foci the salivary glands and the lumen of the midgut and caeca. The salivary glands are the only tissue of the alimentary tract to secrete cellulase, whereas the microflora generates it in the gut. Digestion occurs mainly in the midgut, where a large portion of the insect’s digestive enzymes are produced and secreted, including proteases, lipases, and carbohydrases.

Integumentary nephridia: Integumentary nephridia are smallest nephridia of Pheretima. So they are also called as micro nephridia. They lie scattered on the entire internal surface of the body wall except in the first two segments. They are V shaped structures and hang out in the coelom. The number ranges from 200-250 in each segment, except in the clitellar segments. In the clitellar segments they are ten times more than the usual number.

The wall of the tracheae is made of three layers. They are an outer basement membrane, a middle one cell thick epithelium and an inner layer of cuticle called intima. The intima is produced into spiral thickenings called taenidia. The taenidia keep the tracheae always open and prevent it from collapsing.

The alimentary canal of a cockroach is having three parts, foregut, midgut, and hindgut. Whereas the alimentary canal is divided into three main portions. These are Foregut, which consists of a mouth surrounded by mouthparts. The mouth cavity is the pharynx. It continues as the oesophagus and further the canal enlarges into the crop which is thin-walled. The crop opens into short, muscular organs, the gizzard, or proventriculus. The midgut is found at the junction of the gizzard and the stomach is valves called the stomodael valves. The midgut forms the mesenteron. It consists entirely of the stomach and ventriculus. The hindgut is a coiled structure. It consists of the anterior ileum, middle colon, and posterior rectum.

Thus, the correct answer is an option (C).

Due to the closed circulatory system, blood is confined to the heart and blood vessels. Contractions keep circulating in one direction. Smaller blood vessels supply the gut, nerve cord, and the body wall. Blood glands are present on the 4th,5th and 6th segments. They produce blood cells and haemoglobin which is dissolved in blood plasma. Blood cells are phagocytic in nature. 

A. Correct option is (C)
B. Explanation for the correct option

• In cockroach, the flow of haemolymph is heart → head→ perivisceral sinus → pericardial sinus → ostia → heart.
• The heart in a cockroach is neurogenic. Haemocoel (body cavity) is a perivisceral cavity filled with colourless blood (hemolymph).
• When alary muscle contract the dorsal diaphragm became flat and pericardial increases.
• Blood from the perivisceral sinus enter into pericardial sinus through a pore of dorsal diaphragm become dome-shaped and blood from pericardial sinus is forced into the heart through valvular ostia then the heart and aorta contract peristaltically.
• Blood flow from the posterior end to the anterior end in heart and flow into head sinus through the aorta. 

Cockroaches use their mandibles, or jaws, to bite and chew their food. The foregut opens into a crop, where undigested food is temporarily stored. From the crop, the food enters the gizzard. The gizzard is a muscular stomach with sharp teeth-like structures that grinds the food into smaller pieces.

End plate junction or neuromuscular junction, are specialized chemical synapses formed at the sites where  terminal branches of a motor neuron  is able to contact the  target muscle cell (skeletal muscle) and is achieved by the secretion of acetylcholine.

1. Each myofibril has alternate light and dark bands due to the presence of contractile proteins actin and myosin.
2. Z line is present in the center of each I band but not A band. So, this option is incorrect.
3. As shown in the diagram, A and I bands are arranged alternatively throughout the length of the myofibril.
4. The functional unit of muscle contraction is the sarcomere which shortens and lengthens during muscle contraction and relaxation. 
   
5. The central part of the thick filament which is not overlapped by the thin filament is H zone and not the M line (Refer Diagram).

So, the correct option is '1, 3 and 4 alone are correct'.

There are various receptors present in the human body like caloreceptors, proprioreceptors, frigidoreceptors, exteroceptors, rheoreceptors, baroreceptors, etc. Caloreceptors are heat receptors. Frigidoreceptors are cold receptors. Proprioceptors are muscle position receptor. These are receptors found in muscles. Exteroceptors are found on body surface.

1. The compound eye of cockroach consists of ommatidia, which form their separate image resulting into mosaic vision. The image so formed is incapable of distinct vision and blurred.

Correct Answer: B

A. The ova (eggs) are fertilised by the sperm cells within the cocoon which are deposited in the soil and not inside the body.

Smooth muscles are involuntary muscles present in the alimentary canal, uterus, oviduct etc.

A flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms. Flame cells function like a kidney, removing waste materials.

(i) Bones have a hard and non-pliable ground substance rich in (1) 'calcium salts' and (2) 'collagen fibres' which give bone its strength.

$$\textbf{Correct option: A}$$

$$\textbf{Solution:}$$

Option A:

$$\bullet$$ Spiracles are the pores of respiratory tubes that open on the surface of body of cockroach. There are hair present on these openings to prevent entry of dust particles in the body.

$$\bullet$$ There are two pairs of spiracles are present in the thorax and eight pairs in the abdomen of the cockroach body.

Hence the correct option is option A.

 Dorsal vessel is a longitudinal blood vessel lying above the alimentary canal that extends through the length of the body. It is the largest blood vessel and it extends through the length of the body. It is the largest blood vessel and is contractile.  The anterior part of the dorsal vessel, up to the 13th segment, functions as the distributing vessel.  It also supplies blood to the esophagus, gizzard and pharyngeal nephridia by paired vessel. Behind the 13th segment the dorsal vessel functions as the collecting vessel. It acts as both distributing as well as collecting.

(A) Buccal cavity: 1-3