Maharashtra Board Class 11 Biology Chapter 11 Study of Animal Type Cockroach Solutions

Study Of Animal Type: Cockroach Class 11 Exercise Question Answers Solutions Maharashtra Board

Class 11 Biology Chapter 11 Exercise Solutions Maharashtra Board

Biology Class 11 Chapter 11 Exercise Solutions

Question (A)Chemical nature of chitin is __________.
(A) protein
(B) carbohydrate
(C) lipid
(D) glycoprotein
Answer: (B) carbohydrate & (D) glycoprotein
In simple words: Chitin, a primary component of the cockroach exoskeleton, is fundamentally a carbohydrate, specifically a polysaccharide. However, it can also exist in complexes with proteins, making "glycoprotein" a relevant chemical nature in certain biological contexts.

🎯 Exam Tip: Understanding the chemical composition of structural components like chitin is crucial for explaining the rigidity and protective functions of the insect exoskeleton.

Question (B)Cockroach has __________ type of mouthparts.
(A) sponging
(B) chewing and biting
(C) piercing and sucking
(D) lapping
Answer: (B) chewing and biting
In simple words: Cockroaches possess mouthparts designed for chewing and biting, allowing them to process solid food efficiently. This type of mouthpart structure includes strong mandibles for cutting and crushing.

🎯 Exam Tip: Identifying the type of mouthparts in different insects helps classify their feeding habits and ecological roles.

Question (C)Spiracle is a part of __________ system of cockroach.
(A) circulatory
(B) respiration
(C) reproductive
(D) nervous
Answer: (B) respiration
In simple words: Spiracles are external openings on the body surface of a cockroach that lead into its tracheal system, which is responsible for gas exchange, making them an integral part of the respiratory system.

🎯 Exam Tip: Knowing the function of spiracles is essential for understanding how terrestrial insects breathe and regulate gas exchange with their environment.

Question (D)__________ is a part of digestive system.
(A) Trachea
(B) Hypopharynx
(C) Haemocyte
(D) Seminal vesicle
Answer: (B) Hypopharynx
In simple words: The hypopharynx, also known as the lingua, is a tongue-like structure located within the mouthparts of a cockroach, playing a role in food manipulation and mixing saliva, thus being a part of its digestive system.

🎯 Exam Tip: Accurately identifying the components of the digestive system helps in tracing the path of food and understanding the specific functions of each organ.

Question (E)__________ is also called as brain of cockroach.
(A) Supra-oesophageal ganglion
(B) Sub-oesophageal ganglion
(C) Hypo-cerebral ganglion
(D) Thoracic ganglion
Answer: (A) Supra-oesophageal ganglion
In simple words: The supra-oesophageal ganglion, located in the head, functions as the primary control center for the cockroach's nervous system, analogous to a brain. It processes sensory information and coordinates movements.

🎯 Exam Tip: Understanding the location and function of major ganglia helps clarify the decentralized yet effective nervous system of insects.

2. Answer The Following Questions

Question (A)Describe the digestive system of cockroach. OR With the help of neat and labelled diagram, describe the digestive system of cockroach.
Answer:1. Digestive system of cockroach consists of mouthparts, alimentary canal and salivary glands.
2. Mouthparts: Pre-oral cavity present in front of the mouth receives food. It is bounded by chewing and biting type of mouth parts.
These are movable, segmented appendages that help in ingestion of food. The mouthparts of cockroach comprises of:
(a) Labrum: It forms the upper lip. It is a single flap-like movable part which covers the mouth from upper side. It forms an anterior wall of pre-oral cavity.
Function: It is useful in holding the food during feeding.
(b) Mandibles: These are two dark, hard, chitinous structures with serrated median margins. They are true jaws present on either side, behind the labrum.
Function: They perform co-ordinated side-wise movements with the help of adductor and abductor muscles to cut and crush the food.
(c) Maxillae: These are the accessory jaws. They are also called as first pair of maxillae. These are situated on the either side of mouth behind the mandibles. Each maxilla consists of sclerites like cardo, stipes, galea, lacinia and maxillary palps.
Functions: Maxillae hold food, help mandibles for mastication. They are also used for cleaning the antennae and front legs. Maxillary palps act as tactile organs.
(d) Labium: It forms the lower lip. Labium is also known as second maxilla which covers the pre-oral cavity from the ventral side. It is firmly attached to the posterior part of head. It has three jointed labial palps which are sensory in function.
Function: It is useful in pushing the chewed food in the pre-oral cavity. It prevents the loss of food falling from the mandibles, while chewing.
(e) Hypopharynx: Hypopharynx is also known as lingua. It is a somewhat cylindrical single structure, located in front of the labium and between first maxillae. The salivary duct opens at the base of hypopharynx. Hypopharynx bears comb-like plates called super-lingua on either side. Hypopharynx is present at the centre of the mouth.
Function: It is useful in the process of feeding and mixing saliva with food.
3. Alimentary canal: It is long a (6 - 7cm) tube of different diameters with two openings.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे के मुख भागों को दर्शाता है। इसमें लेब्रम (ऊपरी होंठ), मैंडिबल (जबड़े), मैक्सिला (सहायक जबड़े), लेबियम (निचला होंठ) और हाइपोफैरिंक्स (जीभ) शामिल हैं। यह विभिन्न संरचनाएं भोजन को पकड़ने, काटने, कुचलने और मुंह के अंदर धकेलने में सहायता करती हैं, जो तिलचट्टे के चीरने और काटने वाले मुख भागों की जटिलता को उजागर करती हैं।
4. The alimentary canal is divisible into three parts: foregut, midgut and hindgut
(a) Foregut or stomodaeum: It consists of pharynx, oesophagus, crop and gizzard.
1. Pharynx: It is very short, narrow but muscular tube that opens into oesophagus.
Function: Conduction of food into the oesophagus.
2. Oesophagus: It is slightly long and narrow tube which opens into crop.
3. Crop: Crop is a large, pear shaped and sac- like organ.
Function: It temporarily stores the food and then sends it to gizzard.
4. Gizzard: Gizzard or proventricuius is a small spherical organ. It is provided internally with a circlet of six chitinous teeth and backwardly directed bristles. The foregut ends with gizzard.
Function: The chitinous teeth present in gizzard are responsible for crushing the food and the bristles help to filter the food.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे के पाचन तंत्र को दर्शाता है, जिसमें फैरिंक्स, एसोफैगस, क्रॉप, गिज़ार्ड, हेपेटिक सीका, मेसेंटरॉन (मिडगट), मैलपीघियन ट्यूबूल, इलियम, कोलन और मलाशय जैसे प्रमुख अंग शामिल हैं। यह विभिन्न भागों को स्पष्ट रूप से लेबल करता है और पूरे पाचन पथ की संरचना को दिखाता है, जिससे भोजन के प्रसंस्करण और अपशिष्ट निष्कासन की प्रक्रिया को समझने में मदद मिलती है।
(b) Midgut or mesenteron: It consists of stomach and hepatic caeca.
1. Ventriculus or stomach: It is straight, short and narrow. Stomach is lined by glandular epithelium which secretes digestive enzymes.
Function: It is mainly responsible for digestion and absorption.
2. Hepatic caeca: These are thin, transparent, short, blind (closed) and hollow tubules.
Function: They secrete digestive enzymes.
(c) Hindgut or proctodaeum : It consists of ileum, colon and rectum.
1 lleum: It is short and narrow part of hindgut. Malpighian tubules open in the anterior lumen of ileum, near the junction of midgut and hindgut. Posterior region of ileum contains sphincter.
Ileum directs the nitrogenous wastes and undigested food towards colon.
2. Colon: It is a longer and wider part of the hindgut. It directs waste material towards the rectum. It reabsorbs water from wastes as per the need.
3. Rectum: It is oval or spindle-shaped, terminal part of the hindgut. It contains six rectal pads along the internal surface for absorption of water. Rectum opens into anus. Anus is present on the ventral side of the 10th segment. It is the last or posterior opening of the digestive system. The undigested food is released out of the body through anus.
5. Salivary glands:
a. Cockroach has a pair of salivary glands which secrete saliva.
b. Each salivary gland has two glandular lobes and a receptacle or reservoir.
c. The glandular lobes consists of several irregular-shaped white coloured lobules which secrete saliva.
d. Each gland has a salivary duct.
Both the ducts unite to form a common salivary duct.
e. Receptacle of each salivary gland is thin-walled, elongated, sac-like structure. Each receptacle has a duct. These ducts unite to form common reservoir duct.
f. Common salivary duct and common reservoir duct unite together to form a common efferent salivary duct. The efferent salivary duct opens at the base of tongue or hypopharynx.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे की लार ग्रंथियों को दर्शाता है, जिसमें लोबुलर लार नलिकाएं, सामान्य एफ़ेरेंट लार नलिका, सामान्य जलाशय नलिका, जलाशय या रिसेप्टेकल और लार नलिका जैसे भाग स्पष्ट रूप से लेबल किए गए हैं। यह ग्रंथियों के विभिन्न भागों की व्यवस्था और लार के संग्रह व स्राव के मार्ग को दिखाता है।
In simple words: The cockroach digestive system is a complex tube extending from mouth to anus, divided into foregut, midgut, and hindgut. It efficiently processes food through specialized mouthparts, storage in the crop, grinding in the gizzard, enzymatic digestion in the midgut, and water reabsorption in the hindgut, aided by salivary glands.

🎯 Exam Tip: When describing the digestive system, remember to mention the three main regions (foregut, midgut, hindgut) and the specific functions of key organs like the gizzard and hepatic caeca, often requiring a well-labeled diagram for full marks.

Question (B)Give an account on tracheal system of cockroach.
Answer:1. Cockroach has an internal respiratory system of air tubes called tracheal system by which the air is brought into the body and is in contact with every part of the body. It allows the exchange of gases directly between the air and tissues without the need of blood.
These air tubes of internal respiratory system begin at the opening on body surface called spiracles.
2. Spiracles: They are paired respiratory openings. Spiracles are present on the ventro-lateral side of the body, in pleural membrane. Cockroaches have two pairs of thoracic and eight pairs of abdominal spiracles.The spiracles open into a series of air sacs from which arise the tubes called trachea. The spiracles let the air into and out of trachea.
3. Trachea: The trachea form a definite pattern of branching tubes arranged transversely as well as longitudinally. They are about 1mm thick and have spiral or annular thickening of chitin. The inner lining of chitin prevents the trachea from collapsing. Each trachea further branches into smaller tubes called tracheoles.
4. Tracheoles: These are fine intracellular tubes that penetrate deep into tissues. They are thin and not lined by chitin. They end blindly in the cells. Each tracheole at the blind end is filled with a watery fluid through which exchange of gases takes place. The content of this fluid keeps changing. At high muscular activity, part of fluid part is drawn into the tissues to enable more and rapid oxygen intake.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे के श्वसन प्रणाली को दर्शाता है, जिसमें शरीर की भित्ति का काइटिन, काइटिनमय अस्तर, उपकला, लुमेन, श्वासप्रणाल कोशिका, श्वासप्रणाल, छोटी श्वासप्रणाल, श्वासप्रणाल द्रव, स्पाइरैकल और मांसपेशी फाइबर शामिल हैं। यह विभिन्न घटकों की व्यवस्था को दिखाता है जो गैस विनिमय और ऊतकों तक ऑक्सीजन के सीधे वितरण को सक्षम करते हैं।
In simple words: The cockroach respiratory system, or tracheal system, uses spiracles as external openings leading to a network of trachea and tracheoles that directly deliver oxygen to tissues. This system facilitates gas exchange without relying on blood for oxygen transport.

🎯 Exam Tip: Focus on the hierarchical structure of the tracheal system-spiracles to tracheae to tracheoles-and how it bypasses the circulatory system for direct gas exchange, a key adaptation for insects.

Question (C)Describe the nervous system of cockroach.
Answer:Nervous system in cockroach:
Nervous system of cockroach is ventral, solid and ganglionated. It consists of central nervous system (CNS), peripheral nervous system (PNS) and autonomous nervous system (ANS).
Central nervous system (CNS): Central nerv ous system consists of nerve ring and ventral nerve cord.
1. Nerve ring consists of:
a. a pair of supra-oesophageal ganglia
b. a pair of circum-oesophageal connectives
c. a pair of sub-oesophageal ganglia
(a) Supra-oesophageal ganglia or cerebral ganglia: A pair of supra-oesophageal ganglia is collectively known as the brain. Brain is present in head, above the oesophagus and between antennal bases. Each supra-oesophageal ganglion is formed by the fusion of three small ganglia - protocerebrum, deutocerebrum and tritocerebrum.
(b) Circum-oesophageal connectives: Supra-oesophageal ganglia are connected to sub-oesophageal ganglion by a pair of lateral nerves called as circum-oesophageal connectives. Connectives arise from supra-oesophagial ganglia.
(c) Sub-oesophageal ganglia: It is a bilobed and present below the oesophagus, in head. It is also formed by the fusion of three pairs of ganglia.
2. Ventral nerve cord:
a. It arises from the sub-oesophageal ganglion. It is present along mid-ventral position, in perineural sinus.
b. It is double ventral nerve cord and consists of nine segmental, paired ganglia.
c. First three pairs of segmental ganglia are large and known as thoracic ganglia. The other six pairs of segmental ganglia are in abdomen (abdominal ganglia).
d. 6th abdominal ganglion is the largest and it is present in 7th abdominal segment.
e. There is no ganglion in 6th segment.
Peripheral nervous system (PNS):
1. The peripheral nervous system comprises of nerves that arise from various ganglia of CNS.
2. Six pairs of nerves arise from the supra-oesophageal ganglia. They supply to the eyes, antenna and labrum.
3. Nerves arising from the sub-oesophageal ganglion supply to the mandibles, maxillae and labium.
4. Nerves arising from the thoracic ganglia supply to the wings, legs and internal thoracic organs.
5. Nerves from abdominal ganglia go to the abdominal organs of respective abdominal segments.
6. Autonomic nervous system (ANS): It consists of four ganglia and a retrocerebral complex.
The ganglia are as follows:
1. Frontal ganglion: It is present above the pharynx and in front of brain.
2. Hypocerebral ganglion: It is present on the anterior region of oesophagus.
3. Ingluvial ganglion: It is present on crop. It is also called as visceral ganglion.
4. Ventricular ganglion: It is present on gizzard.
In simple words: The cockroach nervous system is ventral and ganglionated, comprising a central nerve ring (brain and sub-oesophageal ganglion), a ventral nerve cord with segmental ganglia, and a peripheral system that innervates various body parts. It allows for decentralized control and coordinated responses.

🎯 Exam Tip: Highlight the ventral, solid, and ganglionated nature of the cockroach nervous system, emphasizing the role of the supra-oesophageal ganglion as the "brain" and the segmental ganglia in controlling localized functions.

Question (D)With the help of neat labelled diagram, describe female reproductive system of cockroach.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे के मादा प्रजनन तंत्र को दर्शाता है, जिसमें अंडाशय, अंडवाहिनी, सामान्य अंडवाहिनी या योनि, शुक्रधानि, कॉलेटरल ग्रंथियां, जननांग कक्ष, गोनोपोफ़ाइसिस और वेस्टिबुलम जैसे भाग स्पष्ट रूप से लेबल किए गए हैं। यह संरचना अंडे के उत्पादन, निषेचन और अंडे के कैप्सूल (उठेका) के निर्माण के लिए अंगों की व्यवस्था को दिखाता है।
1. Female reproductive system of cockroach consists a pair of ovaries, a pair of oviducts, vagina, spermatheca and accessory glands.
2. Ovaries are primary reproductive organs. They are paired and lie lateral in position in 2nd - 6lh abdominal segments. Each ovary is formed of a group of 8 ovarian tubules or ovarioles, containing a chain of developing ova. All ovarioles of an ovary open in lateral oviduct of respective side.
3. The lateral oviducts unite to form a common oviduct or vagina.
Common oviduct or vagina opens into the Bursa copulatrix (genital chamber), the female organ of copulation.
4. Spermatheca, is a sperm storing structure present in the 6th segment opens into genital chamber. It receives the sperms during copulation and store them for fertilization.
5. Collaterial glands are accessory paired glands that open in genital chamber.
6. Female gonapophyses consists of six chitinous plates surrounding the genital pore.
7. In males, genital pouch or genital chamber lies at the hind end of abdomen which is bounded dorsally by 9th and 10th terga and ventrally b; male genital pore and gonapophysis.
In simple words: The female reproductive system of a cockroach includes a pair of ovaries, oviducts, a vagina, spermatheca for sperm storage, and collaterial glands. These structures work together for egg production, fertilization, and the formation of the ootheca.

🎯 Exam Tip: For this question, a clear, labeled diagram is critical. Ensure you accurately identify the ovaries (with ovarioles), oviducts, spermatheca, and collaterial glands, explaining their role in egg development and ootheca formation.

Question (E)Draw a labelled diagram of digestive system of a cockroach.
Answer:1. Digestive system of cockroach consists of mouthparts, alimentary canal and salivary glands.
2. Mouthparts: Pre-oral cavity present in front of the mouth receives food. It is bounded by chewing and biting type of mouth parts.
These are movable, segmented appendages that help in ingestion of food. The mouthparts of cockroach comprises of:
(a) Labrum: It forms the upper lip. It is a single flap-like movable part which covers the mouth from upper side. It forms an anterior wall of pre-oral cavity.
Function: It is useful in holding the food during feeding.
(b) Mandibles: These are two dark, hard, chitinous structures with serrated median margins. They are true jaws present on either side, behind the labrum.
Function: They perform co-ordinated side-wise movements with the help of adductor and abductor muscles to cut and crush the food.
(c) Maxillae: These are the accessory jaws. They are also called as first pair of maxillae. These are situated on the either side of mouth behind the mandibles. Each maxilla consists of sclerites like cardo, stipes, galea, lacinia and maxillary palps.
Functions: Maxillae hold food, help mandibles for mastication. They are also used for cleaning the antennae and front legs. Maxillary palps act as tactile organs.
(d) Labium: It forms the lower lip. Labium is also known as second maxilla which covers the pre-oral cavity from the ventral side. It is firmly attached to the posterior part of head. It has three jointed labial palps which are sensory in function.
Function: It is useful in pushing the chewed food in the pre-oral cavity. It prevents the loss of food falling from the mandibles, while chewing.
(e) Hypopharynx: Hypopharynx is also known as lingua. It is a somewhat cylindrical single structure, located in front of the labium and between first maxillae. The salivary duct opens at the base of hypopharynx. Hypopharynx bears comb-like plates called super-lingua on either side. Hypopharynx is present at the centre of the mouth.
Function: It is useful in the process of feeding and mixing saliva with food,
3. Alimentary canal: It is long a (6 - 7cm) tube of different diameters with two openings.
4. The alimentary canal is into three parts: foregut, midgut and hindgut
(a) Foregut or stomodaeum: It consists of pharynx, oesophagus, crop and gizzard.
1. Pharynx: It is very short, narrow but muscular tube that opens into oesophagus.
Function: Conduction of food into the oesophagus.
2. Oesophagus: It is slightly long and narrow tube which opens into crop.
3. Crop: Crop is a large, pear shaped and sac- like organ.
Function: It temporarily stores the food and then sends it to gizzard.
4. Gizzard: Gizzard or proventricuius is a small spherical organ. It is provided internally with a circlet of six chitinous teeth and backwardly directed bristles. The foregut ends with gizzard.
Function: The chitinous teeth present in gizzard are responsible for crushing the food and the bristles help to filter the food.
(b) Midgut or mesenteron: It consists of stomach and hepatic caeca.
1. Ventriculus or stomach: It is straight, short and narrow. Stomach is lined by glandular epithelium which secretes digestive enzymes.
Function: It is mainly responsible for digestion and absorption.
2. Hepatic caeca: These are thin, transparent, short, blind (closed) and hollow tubules.
Function: They secrete digestive enzymes.
(c) Hindgut or proctodaeum : It consists of ileum, colon and rectum.
1 lleum: It is short and narrow part of hindgut. Malpighian tubules open in the anterior lumen of ileum, near the junction of midgut and hindgut. Posterior region of ileum contains sphincter.
Ileum directs the nitrogenous wastes and undigested food towards colon.
2. Colon: It is a longer and wider part of the hindgut. It directs waste material towards the rectum. It reabsorbs water from wastes as per the need.
3. Rectum: It is oval or spindle-shaped, terminal part of the hindgut. It contains six rectal pads along the internal surface for absorption of water. Rectum opens into anus. Anus is present on the ventral side of the 10th segment. It is the last or posterior opening of the digestive system. The undigested food is released out of the body through anus.
5. Salivary glands:
a. Cockroach has a pair of salivary glands which secrete saliva.
b. Each salivary gland has two glandular lobes and a receptacle or reservoir.
c. The glandular lobes consists of several irregular-shaped white coloured lobules which secrete saliva.
d. Each gland has a salivary duct.
Both the ducts unite to form a common salivary duct.
e. Receptacle of each salivary gland is thin-walled, elongated, sac-like structure. Each receptacle has a duct. These ducts unite to form common reservoir duct.
f. Common salivary duct and common reservoir duct unite together to form a common efferent salivary duct. The efferent salivary duct opens at the base of tongue or hypopharynx.
In simple words: The digestive system of a cockroach consists of mouthparts, an alimentary canal (foregut, midgut, hindgut), and salivary glands. It processes food through mechanical crushing, storage, enzymatic digestion, and absorption, efficiently extracting nutrients from a varied diet.

🎯 Exam Tip: This question requires you to recall and reproduce the labeled diagram of the cockroach digestive system accurately. Pay close attention to the distinct regions (foregut, midgut, hindgut) and their respective organs like crop, gizzard, hepatic caeca, and malpighian tubules, detailing their functions for a complete answer.

Question (F)A student observed that the cockroaches are killed for dissection by simply putting them in soap water. He inquired whether soap is so poisonous. Teacher said it is due to its peculiar respiratory system. How?
Answer:Cockroaches when put in soap solution, the solution enters into their body through the small respiratory openings called spiracles. The spiracles lead to trachea which further branches into smaller tubes called tracheoles. Each of these tracheoles has body fluid which acts as a stationary medium for diffusion. The soap solution rapidly diffuses through the entire respiratory system which may result in suffocation and eventually lead to the death of cockroach.
In simple words: Cockroaches die in soap water not because soap is poisonous, but because the soapy solution enters their spiracles and clogs their tracheal system, preventing gas exchange and causing suffocation due to their unique respiratory anatomy.

🎯 Exam Tip: This question assesses your understanding of the cockroach's tracheal respiratory system. Explain how soap water physically obstructs spiracles and diffuses into tracheoles, disrupting oxygen supply and leading to death by suffocation.

Question (G)Describe the circulatory system of cockroach.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र तिलचट्टे के संचार प्रणाली को दर्शाता है, जिसमें पूर्वकाल महाधमनी, अलारी मांसपेशियां और हृदय के कक्ष शामिल हैं। यह एक खुली संचार प्रणाली को दर्शाता है जहां रक्त (हेमोलिम्फ) शरीर के गुहाओं (हेमोकोएल) में सीधे बहता है, हृदय के कक्षों के माध्यम से पंप किया जाता है, और अलारी मांसपेशियों द्वारा सहायता प्राप्त होती है।
1. Haemolymph: Haemolymph is colourless as it is without any pigment. It consists of plasma and seven types of blood cells/haemocytes. Plasma consists of water with some dissolved organic and inorganic solutes. It is rich in nutrients and nitrogenous wastes like uric acid.Cockroach has open circulatory system. It consists of colourless blood (haemolymph), a dorsal blood vessel (heart and dorsal aorta) and haemocoel.
2. Haemocoel: The body cavity of cockroach (haemocoel) can be divided into three sinuses due to two diaphragms i.e. dorsal and ventral diaphragm. These diaphragms are thin, fibromuscular septa (sing.septum) which remain attached to terga along lateral sides at intermittent points.
(a) Dorsal diaphragm: It has 12 pairs (10 abdominal and 2 thoracic) of fan-like alary muscles. Alary muscles are triangular with pointed end attached to terga at lateral side and broad end lies between the heart and dorsal diaphragm.
(b) Ventral diaphragm: It is flat and present just above the ventral nerve cord. Laterally, it is attached to sterna at intermittent points.
(e) Sinuses: The coelom of cockroach is divided into three sinuses - pericardial sinus, perivisceral sinus and perineural sinus.
1. Pericardial sinus: It is dorsal, very small and contains dorsal vessel.
2. Perivisceral sinus: It is middle and largest sinus. It contains fat bodies and almost all major visceral organs of alimentary canal and reproductive system.
3. Perineural sinus: It is ventral, small and contains ventral nerve cord. It is continuous into legs. All the three sinuses communicate with each other through the pores present between two successive points of attachments of diaphragms.
4. Dorsal blood vessel: This is present in pericardial sinus, just below the tergum. It is divisible into posterior heart and anterior aorta (dorsal aorta/cephalic vessel).
(a) Heart: It is about 2.5 cm long, narrow, muscular tube that is open anteriorly and closed posteriorly. It starts from 9th abdominal segment and extends anteriorly upto 1st thoracic segment. Heart of cockroach is 13 chambered, out of which 10 chambers are in abdominal region and 3 chambers are in thoracic region. Each chamber has a pair of vertical slit-like incurrent aperture or opening called ostium (plural: ostia). Ostia are present along lateral side in the posterior region of first 12 chambers. Each ostium has lip-like valves that allow the flow of blood from sinus to heart only.
(b) Anterior aorta: Heart is continued by a short, thin-walled vessel called dorsal aorta. It lies in head region and opens in haemocoel.
In simple words: Cockroaches have an open circulatory system where colorless haemolymph (blood) directly bathes organs within the haemocoel. The dorsal blood vessel, acting as a heart, pumps haemolymph through a series of chambers and into the body sinuses, with alary muscles aiding circulation.

🎯 Exam Tip: When describing the circulatory system, emphasize that it is "open" and does not transport respiratory gases. Detail the composition of haemolymph, the division of the haemocoel into sinuses by diaphragms, and the structure of the dorsal tubular heart with its ostia and alary muscles.

3. Answer The Following Questions

Question (A) How will you identify male or female cockroach?
Answer:Male and female cockroach can be identified with the help of following differences:

🎯 Exam Tip: When asked to differentiate, create a clear two-column table to present the contrasting features systematically for better scores.

Question (B) Write a note on: Gizzard of cockroach.
Answer:Gizzard: Gizzard or proventricuius is a small spherical organ. It is provided internally with a circlet of six chitinous teeth and backwardly directed bristles. The foregut ends with gizzard. Function: The chitinous teeth present in gizzard are responsible for crushing the food and the bristles help to filter the food.In simple words: The gizzard in a cockroach is a small, spherical part of its digestive system containing chitinous teeth and bristles. Its main job is to crush and filter food before it moves further into the digestive tract.

🎯 Exam Tip: Clearly state the structure and precise function of the gizzard, emphasizing the role of chitinous teeth and bristles.

Question (C) Give the systematic position of cockroach.
Answer:Systematic position of cockroach:

🎯 Exam Tip: Present the systematic position in a clear hierarchical order with concise reasons for each classification level.

Question (D) What would have happened if cockroach did not have gizzard?
Answer:1. The gizzard in cockroach is a spherical organ which has chitinous teeth and bristles. 2. The chitinous teeth present in gizzard are responsible for crushing the food and the bristles help to filter the food. 3. If the cockroach did not have gizzard, the food will not be crushed into small particles and unfiltered food will enter the hindgut. Thus, digestion will be affected in the absence of gizzard.In simple words: Without a gizzard, cockroaches would be unable to crush and filter their food effectively. This would lead to large, unfiltered food particles entering the hindgut, severely hindering the digestion process.

🎯 Exam Tip: Focus on the direct consequence of the gizzard's absence, linking its structural components (teeth, bristles) to its function (crushing, filtering) and the impact on overall digestion.

Question (E) What is the functional difference between eyes of cockroach and human being?
Answer:1. Cockroaches have compound eyes whereas humans have simple eyes. 2. Eyes of cockroach possess several ommatidia that collectively form an image and help them to detect even the slightest movement of its predator. They provide mosaic or hazy vision. 3. Human eyes contain single lens and a clear image is formed on the retina. Humans have binocular vision which provides an improved perception of depth and gives a three-dimensional image of their surroundings.In simple words: Cockroaches have compound eyes that detect movement and create a mosaic image, offering wide-angle vision but less detail. Humans, however, have simple eyes with a single lens, providing clear, high-resolution, and three-dimensional binocular vision.

🎯 Exam Tip: Clearly distinguish between compound and simple eyes, highlighting how the structural differences (ommatidia vs. single lens) lead to distinct visual capabilities (mosaic/movement detection vs. sharp, 3D vision).

Question (F) What is the functional difference between respiratory systems of cockroach and human being?
Answer:The functional difference between the respiratory systems of cockroach and human being is that in respiratory system of cockroach transport of gases does not occur via. blood whereas in human respiratory system transport of gases takes place via blood. In cockroach, the circulatory system has no role in respiratory process whereas in humans, circulatory system plays an important in respiratory process.In simple words: The key difference is how gases are transported: in cockroaches, the tracheal system directly delivers air to tissues, bypassing the blood; in humans, the circulatory system (blood) is essential for transporting oxygen and carbon dioxide.

🎯 Exam Tip: Emphasize the direct vs. indirect gas exchange mechanism and the involvement (or lack thereof) of the circulatory system in each organism's respiration.

4. Explain The Following In Short.

Question (A) What are anal cerci?
Answer:1. Anal cerci are a pair of appendages at the end of the abdomen that arise from the 10th segment of the body of both male and female cockroach. 2. They are sensitive to wind movements and detect vibrations.In simple words: Anal cerci are sensory appendages found on the 10th abdominal segment of both male and female cockroaches, primarily used for detecting air movements and vibrations, helping them sense their surroundings.

🎯 Exam Tip: Define their location and state their specific sensory functions clearly.

Question (B) What is ganglion?
Answer:1. Ganglion is a group of nerve cell bodies. 2. It represents the brain in advanced invertebrates.In simple words: A ganglion is a cluster of nerve cell bodies, which acts as a processing center for nerve signals and functions much like a simple brain in many invertebrates.

🎯 Exam Tip: Provide a concise definition and mention its functional significance, especially in the context of invertebrates.

Question (C) Write a short note on hypopharynx.
Answer:Hypopharynx: Hypopharynx is also known as lingua. It is a somewhat cylindrical single structure, located in front of the labium and between first maxillae. The salivary duct opens at the base of hypopharynx. Hypopharynx bears comb-like plates called super-lingua on either side. Hypopharynx is present at the centre of the mouth. Function: It is useful in the process of feeding and mixing saliva with food.In simple words: The hypopharynx, or lingua, is a tongue-like structure in the cockroach mouth, positioned between the labium and maxillae, where salivary ducts open. It helps mix saliva with food during feeding.

🎯 Exam Tip: Include both the alternate name (lingua), its location relative to other mouthparts, and its primary function in feeding and saliva mixing.

Question (D) What is mesentron?
Answer:Midgut or mesenteron: It consists of stomach and hepatic caeca. 1. Ventriculus or stomach: It is straight, short and narrow. Stomach is lined by glandular epithelium which secretes digestive enzymes. Function: It is mainly responsible for digestion and absorption. 2. Hepatic caeca: These are thin, transparent, short, blind (closed) and hollow tubules. Function: They secrete digestive enzymes.In simple words: The mesenteron, also known as the midgut, comprises the stomach (ventriculus) and hepatic caeca. The stomach digests and absorbs food, while the hepatic caeca secrete digestive enzymes.

🎯 Exam Tip: Clearly define mesenteron as the midgut and detail its components (stomach and hepatic caeca) along with their specific functions in digestion.

Question (E) Location of tergum.
Answer:1. Tergum is a chitinous plate located in the abdomen of cockroach. 2. The abdomen is elongated and made up of ten segments. Each segment has a dorsal tergum and ventral sternum. Tergum is jointed to the sternum laterally by a soft cuticle called pleura.In simple words: A tergum is a chitinous plate forming the dorsal (upper) part of each abdominal segment in a cockroach, connected laterally to the ventral sternum by a flexible cuticle called the pleura.

🎯 Exam Tip: Specify its location (dorsal abdomen) and mention its relationship with other skeletal plates (sternum, pleura).

Question (F) What is ootheca?
Answer:1. The secretion of collaterial glands forms a capsule around them is called as ootheca or egg case. 2. It is about 8 mm long and ranges from dark reddish to blackish brown. 3. Ootheca contains 14 to 16 fertilized eggs in two rows. 4. They are dropped or glued to a suitable surface, like a crack or crevice with good humidity near a food source. 5. A female cockroach on an average, produces 9 to 10 oothecae during its lifespan.In simple words: An ootheca, or egg case, is a protective capsule formed by collaterial gland secretions, typically containing 14-16 fertilized cockroach eggs. It's usually dark, about 8mm long, and deposited in hidden, humid spots.

🎯 Exam Tip: Define ootheca, describe its physical characteristics (size, color, egg count), and explain its function (protection and deposition).

Question (G) How many chambers are present in heart of a cockroach?
Answer:13 chambers are present in heart of a cockroach, out of which 10 chambers are in abdominal region and 3 are in thoracic region.In simple words: A cockroach heart has 13 chambers in total, with 10 located in the abdomen and 3 in the thoracic region.

🎯 Exam Tip: State the total number of chambers and their distribution between the abdominal and thoracic regions.

Practical/Project:

Question 1. Visit to nearest sericulture farm and study the life cycle of silk worm.
Answer:1. The life cycle of the silk moth consists of four stages namely, egg, larva, pupa and adult. 2. Thousands of eggs deposited by female moths are incubated artificially to reduce the incubation period. 3. Larvae hatching out of eggs are released on mulberry plants to obtain nourishment from mulberry leaves. 4. After feeding for 3 - 4 weeks, larvae move to branches of mulberry plant. 5. The silk thread is formed from the secretion of salivary glands of larvae. 6. Larvae spin this thread around themselves forming a cocoon, which may be spherical in shape. 7. Ten days before the pupa turns into an adult, all the cocoons are transferred into boiling water. 8. Due to the boiling water, the pupa dies in the cocoon and silk fibres become loose. 9. These fibres are then unwound, processed and reeled. 10. Different kinds of fabric are woven from silk threads.In simple words: The silkworm life cycle involves egg, larva, pupa, and adult stages, with larvae feeding on mulberry leaves and spinning cocoons of silk thread. These cocoons are then processed by boiling to extract silk fibers for weaving.

🎯 Exam Tip: For practical-based questions, describe the stages sequentially and highlight the key activities at each stage relevant to the practical aspect (e.g., silk production).

11th Biology Digest Chapter 11 Study Of Animal Type: Cockroach Intext Questions And Answers

Can You Recall? (Textbook Page No. 127)

Question. How many different types of animals are present around us?
Answer:Animals on earth show great diversity. The different types of animals present around us are; a. Unicellular and multicellular
b. Prokaryotic and eukaryotic
c. Vertebrates and invertebrates
d. Unisexual and hermaphrodite
e. Aquatic, terrestrial, amphibian, reptilian, aerial, etc.In simple words: Animals around us exhibit vast diversity, ranging from unicellular to multicellular, prokaryotic to eukaryotic, vertebrates to invertebrates, unisexual to hermaphrodite, and living in various environments like aquatic, terrestrial, or aerial.

🎯 Exam Tip: Provide a comprehensive list of different classification bases to showcase the breadth of animal diversity.

Question. Can a person do a complete detailed study of each of those animals?
Answer:Yes, a person can do a complete detailed study of each of those animals. Classification of animals based on characteristics into various groups has made it easier to study them.In simple words: Yes, a complete detailed study of all animals is feasible through systematic classification, which groups them based on shared characteristics, simplifying the study of their vast diversity.

🎯 Exam Tip: Link the feasibility of studying diverse animals to the concept and importance of animal classification.

Question. Which phylum is most diverse and populous?
Answer:Phylum Arthropoda is most diverse and populous.In simple words: Phylum Arthropoda is the most diverse and populous phylum, containing the largest number of known species on Earth.

🎯 Exam Tip: State the phylum directly and concisely, as this is a factual recall question.

Curiosity Box: (Textbook Page No. 127)

Question. Why do insects need moulting?
Answer:a. Insects undergo metamorphosis (change of form or structure in an individual after hatching or birth). Each time an insect enters the next growth stage it has to molt. b. Moulting is the process in which formation of new chitinous exoskeleton and subsequent shedding of the old one occurs. c. The insects need moulting as their exoskeleton is rigid unlike the skin and does not allow the body to grow.In simple words: Insects need moulting because their rigid chitinous exoskeleton doesn't grow with their body. To progress through developmental stages and increase in size, they must shed the old exoskeleton and form a new, larger one.

🎯 Exam Tip: Explain that moulting (ecdysis) is essential for growth in insects due to their non-expandable exoskeleton, linking it to metamorphosis.

Question. What is the difference between simple and compound eyes?
Answer:

🎯 Exam Tip: Use a comparative table to clearly highlight the structural components (single lens vs. ommatidia) and functional outcomes (single image vs. mosaic/movement detection) of each eye type.

Use Your Brainpower. (Textbook Page No. 131)

Question. Why do body cavity of cockroach is called as haemocoel?
Answer:The body cavity of cockroach is known as haemocoel as it is filled with haemolymph (blood). Cockroaches have open type of circulation thus; the body cavity is filled with haemolymph.In simple words: The body cavity of a cockroach is called a haemocoel because it is filled with haemolymph (insect blood) due to their open circulatory system, where organs are directly bathed in this fluid.

🎯 Exam Tip: Connect the term "haemocoel" directly to the presence of "haemolymph" and the characteristic "open circulatory system" of cockroaches.

Internet My Friend. (Textbook Page No. 136)

Question. Collect the information about techniques and objectives of rearing the cockroaches in countries like China and make a Powerpoint presentation including video clips.
Answer:1. Cockroach rearing industry is a booming industry in China. Cockroaches are reared in more than hundred farms in China. A giant farm in China produces around 6 billion cockroaches. 2. It is believed that cockroaches can be used to prepare a medicine that can prevent stomach cancer. They are also used to treat compost waste.In simple words: Cockroach farming is a growing industry in China, with large-scale operations rearing billions of cockroaches. These insects are being explored for their potential in traditional medicine, particularly for preventing stomach cancer, and for their role in waste treatment.

🎯 Exam Tip: When describing an industry, mention its scale, key applications, and any innovative uses or beliefs associated with it.

11th Std Biology Questions And Answers: