In the female, gonapophyses belong to the 8th and 9th abdominal segments to form an ovipositor. Legs : The cockroach has 3 paris of jointed legs which are attached ventrolaterally to the thorax. 3. Heart of cockroach is neurogenic (heart beat is initiated by a nerve impulse). It tapers posteriorly and terminates into a duct near the male gonopore on the left phallomere. They are Periplaneta Americana, P. australasiae, Blatta orientalis and Blatella germanica and two species of Ectobius. Central Nervous System, Peripheral Nervous System and Sympathetic Nervous System. The protopodite is made of two joints- proximal cardo and distal stipes.Exopodite is a five jointed structure, the maxillary palp, which arises from a small palpifer (a small projection). Anal styles are absent in female is produced backward into a pair of large oval opical lobes or gynovalvular plates which from a keel like structure, which distinguishes the female from the male. With the help of several ommatidia, a cockroach can receive several images at a time of an object. Mechanism of Respiration 10. The heart receives blood from the pericardial sinus through ostia. On the other hand, antennae, are regions present the head. They are used for flight, but in the resting position, lie folded below the tegmina. There are 10 pairs of slit like apertures called spiracles lead in to lateral side of the body. Each maxilla consists of three parts: (a) Protopodite: It is a basal portion and made up of two parts: the proximal cardo and the distal stipes. Antennae also respond to smell. In this condition some fluid from the cells passes into the tracheoles. Metathoracic wings are attached with the anterolateral margin of the metathoracic tergum. The contractile alary muscles play a significant role in the blood flow from the heart to other haemocoelic spaces in blood circulation. Q10. The peritrophic membrane is made up of protein & chitin. A narrow opening, the mouth lies at the base (bottom) of pre-oral cavity which is bounded by the mouth parts. It is a mobile connective tissue composed of corpuscles and a colourless fluid, the plasma. (3mks) (ii) Carefully cut the whole left maxilla. Habitat and Habits of Cockroach: Cockroaches are found in warm, dark and damp places. Its wall consists of strong circular muscles which are needed by the gizzard for grinding. On the other hand, antennae, are regions present the head. The frons is followed by a rectangular plate, the clypeus. It forms an anterior wall of preoral cavity. The mandibles are used for chewing the food: the lacinia, galea, glossa and paraglossa assist in holding it and pushing it into the mouth, while the palps are olfactory in function. They respond to touch. We termed this response the maxilla-labia response (MLR). Labrum is also called upper tip. Digested food is absorbed by the internal lining of the mid-gut and also by the hepatic caecae through diffusion. The first five ganglia are more or less similar but the sixth abdominal ganglion is large. In the thoracic and abdominal regions the haemocoel is divided by two horizontal partitions, the diaphragms, into three large spaces. Cockroaches are used as experimental animals as they can be obtained easily without causing much ecological imbalance. Cockroach excretes uric acid, so it is uricotelic. The genital structures in both sexes are surrounded by sclerites called gonoapophyses .In male they form external genitalia. It is the anterior most region of the body, which lies at right angle to the long axis. In males the 8th and 9th sterna are concealed by 7th sternum which projects a pair of unjointed anal styles. From the junction of mid-gut and gizzard arise six to eight finger-like blind structures called the hepatic caecae or gastric caecae. These are dark stiff opaque and leathery. The claws and pads help the cockroach in grasping the substratum firmly. Structural organization in animals - Live Session - NEET 2020 Contact Number: 9667591930 / 8527521718 The three thoracic ganglia are situated in the pro, meso-, and meta-thoracic segments. The maxilla is the upper jaw bone. In cockroach vision is mosaic and apposition image is formed (although cockroach is nocturnal), if pigmented iris sheath is removed from the compound eye of insects, only superposition image will be formed. Q10. Obviously, the rate of gaseous exchange increases during active life. It comprises various nerves originating from the brain, sub- oesophageal ganglion and the ganglia of the nerve cord. 14. It is a narrow opening that lies at the base of the pre oral cavity. These nerves come out from the hind brain and each soon divides into a frontal connective which runs anteriorly and medially to the frontal ganglion of the sympathetic nervous system and the labral nerve to labrum. The cockroach has an open circulatory system. How will you distinguish them based on the nature of plasma & blood cells? Note: Actually only two pairs of maxillipeds take part in the feeding process. Expansion of the body cavity allows the space inside the tracheae to expand. There are present ten terga. The latter are used to carry eggs to the oothecal chamber. The last chamber is closed posteriorly. However, only few studies have looked into individuality with respect to performance in learning and memory tasks. Fat and glucose are mainly utilized in the production of energy to be used for various body activities. After running a short distance, the recurrent nerve becomes thickened to form the occipital ganglion. The mid-gut is lined by glandular epithelial cells which secrete a digestive secretion containing proteolytic, amylolytic and lipolytic enzymes. The female cockroach bears broad abdomen, brood pouch, but lacks anal styles, as present in the males. They are also sensitive to sound and other vibrations. At the posterior end of each chamber, a pair of apertures, the ostia, are present laterally. is one of a pair of 3 sets of the mouth appendages on the heads of the shrimp modified to rummage and bring food to the mouth. The labrum holds the food particles during the feeding. 2. They are embedded in the fat bodies from the 2nd to the 6th abdominal segments. • The maxillae (single maxilla) move food particles backwards into the preoral cavity. This test is Rated positive by 89% students preparing for Class 11.This MCQ test is related to Class 11 syllabus, prepared by Class 11 teachers. The following is the structure of each of the mouthpart, Labrum: The mouth is … Body Cavity of Cockroach 3. This allows their legs to start moving when vibrations are sensed, often before their brain even processes a … They are numerous small sacs which store the sperms. In the 10th segment just below the tergum, is the anus is supported by four podicel plates. (d) Maxilla; mandible; labrum; antennae. It consists of two parts. The first pair of spiracles is known as mesothoracic, lying in front of the mesothorax between the bases of first and second pairs of legs. Utricular gland (= Mushroom shaped gland): The junction of the vasa deferentia and the ejaculatory duct is surrounded by a mushroom-shaped gland, utricular eland lying in the 6th-7th abdominal segments. When both the mandibles work simultaneously in a horizontal plane, the food matter is cu and masticated into fine and smaller pieces. The latter is used to guide the fertilized eggs towards the oothecal chamber for ootheca formation. The mouth lies at the lower part of the head, and the appendages associated with the mouth are called mouth parts. It is the largest part of the body narrows posteriorly. When the cockroach is active, the osmotic pressure in tissue fluid increases due to high metabolic rate. How many segments is the abdomen of a cockroach divided into? A double ventral nerve cord extends from the sub-oesophaseal ganglion ventral to the alimentary canal. The secretion of ejaculatory duct forms the middle layer of spermatophore. (i) A tent-like plate called tentorium, forms the endoskeleton of head. The eggs come from both the ovaries alternately into the common oviduct and pass through the female gential pore into the genital chamber where they are fertilized by the sperms coming from the left spermatheca. The fat body of cockroach is functionally analogous to the liver of vertebrates. A frontoclypeal suture is present in between the frons and clypeus. A movable chitinous flap, the labrum hangs from the lower edge of the clypeus. Some blood-filled spaces are also found in the head which are known as head sinuses. TOS4. Thus, each compound eye contains about 2000 ommatidia. The posterior end of the abdomen bears the following appendages: These are paired, jointed outgrowths, which arise from the 10th tergum. A five-jointed maxillary palp arises from the outer side of the stipes and is used as a feeler. They exhibit sexual dimorphism, e., male and female individuals can be distinguished externally. Answer: Maxilla, mandible, and labrum are the names of mouthparts of a cockroach. Columnar Epithelium: The columnar epithelium is composed of tall and slender cells. Endocrine System 13. The nervous system of cockroach consists of a nerve ring and a ganglionated double ventral nerve cord, sub-oesophageal ganglion , circum– oesophageal connectives and double ventral nerve cord (Figure 4.13). The first chamber of the heart forms a single narrow tubular anterior aorta leading into the head sinuses. Three layered spermatophores are transferred to the female genital chamber by the male phallomeres. In addition to the main heart there are present very small accessories “hearts” or pulsatile vesicles one at the base of each antenna located in the head, to pump the blood from the head sinuses to the antenna. Ostia are guarded by auricular valves to check the flow of blood from the heart to the pericardial sinus. Each thoracic segment is covered dorsally by a sclerite, the tergum or notum ventrally by another scherite, the sternum and laterally by two cuticular pleura.Terga, sterna and pleura are joined with one another arthrodial membrane. After reading this essay you will learn about: 1. It is a thick walled somewhat rounded structure whose walls are muscular and greatly folded. The receptive part is made up of spindle shaped rhabdome secreted by eight retinular cells or retinulae. Tormogen cells secrete membranes around the bristles. At the apical end of the maxilla are attached galea and lacinia, the former functions like a cover and the latter is toothed and is used for chewing food. The latter is divided by ‘λ’ shaped epicranial suture into two epicranial plates. The six chitinous plates, the phallomeres, surrounding the female genital pore, are termed as gonapophyses. The latter tapers into two sharp claw like projections. Digestive Glands of Cockroach: There are paired salivary glands lying one on each side of the oesophagus and crop. Roaches don’t have teeth, but they do have a complex structure used for chewing and biting. Thus 14-16 young cockroaches (nymphs) develop in one ootheca. Essay # 10. Amino acids are mostly utilized in synthesis of proteins. It is a thin walled somewhat coiled tube with almost uniform thickness. Many animals such as amphibians {e.g., frogs, toads), lizards, birds and rodents eat cockroaches. It consists of six chitinous plates or sclerities. The endopodites form an inner glossa and an outer paraglossa. These glands produce a secretion with a characteristic odour. The hind wings are large, thin, membranous and transparent. Identify the function of the following structures of cockroaches. It is a thick innermost layer formed of soft laminated chitin. Digestion starts in the pre-oral cavity. They are also sensitive to touch. Hence, the tracheoles remain empty and the inspired air directly reaches the tissue cells for gaseous exchange. Tarsus it is a terminal part of the leg and composed of five tarsomeres. The placement of ootheca is called oviposition. (ii) In the thorax, separate processes of stemites of the three segments form endoskeleton. 5. They are arranged on each side of the heart and hence they are also called pericardial cells. a) 3 b) 6 c) 10 d) 2 Answer: c Clarification: The abdomen of the cockroach is located after the head and thorax. Each eye consists of about 2000 hexagonal ommatidia. On either side of the head lies a vertical plate called gena. Draw and label. Both the parts are bent at an angle to each other, (b) Endopodite: It arises from the inner side of the stipes and consists of two parts: outer broad, hood-like galea and an inner, hard plate-like lacinia. The sclerites are joined with one another by thin flexible, soft articular or arthrodial membranes. The palp bears bristles that act as sense organs. It comprises the ileum, colon, rectum and anus. Elimination of uric acid as excretory product is called uricotelic excretion. They function like rear antennae and are connected to the roach’s legs by the abdominal nerve ganglia. a) 3 b) 6 c) 10 d) 2 Answer: c Clarification: The abdomen of the cockroach is located after the head and thorax. iii) Two ovaries are found lying laterally around 2 nd to 6 th abdominal segments. The tissue fluid conveys respiratory gases to and from the cells of the body. In the Malpighian tubules bicarbonates of potassium and sodium, water and uric acid are formed. The labium and labrum also help the pro-legs in this action. Respiratory System of Cockroach: Being terrestrial, cockroach utilizes atmospheric oxygen for respiration. They have a five segmented palp which is sensory and often concerned with taste. It bears the opening of the salivary gland. It is a tubular thin walled structure and succeeds anterior part of the thorax. The ventral diaphragm also projects upwards and separates the perivisceral sinus from the perineural sinus. Before sharing your knowledge on this site, please read the following pages: 1. It is a slit like opening of the alimentary canal lying at the hind end of the abdomen below the 10th tergum. The pro-leucocyte corpuscles are small, but having proportionately large nuclei, which occupy the main space of the cells. They have a five segmented palp which is sensory and often concerned with taste. The sperms produced by the sperm follicles of the testes are passed to the vasa- efferentia which refer to the vasa-deferentia. The exoskeletons provides surface for attachment of muscles and also protect the body. Respiratory System 9. The latter help in the absorption of water. It consists of three parts- the upper broad sub-mentum the middle small mentum and the lower pre-mentum.