In Class 11 Biology, "Structural Organisation in Animals" provides an authoritative, curriculum-verified master resource aligned with the 2026–27 NCERT syllabus.
How does a common household cockroach survive for over a week after having its head completely chopped off? Animal histology and the decentralized open anatomy of periplaneta americana.
यह अध्याय क्यों महत्वपूर्ण है
In Class 11 Biology, "Structural Organisation in Animals" provides an authoritative, curriculum-verified master resource aligned with the 2026–27 NCERT syllabus.
अध्ययन से पूर्व (आवश्यक ज्ञान)
Cellular differentiation from Class 9.
Epithelial, connective, muscular, and nervous tissues.
Analyze Anatomy of Cockroach: Digestive system (gizzard, hepatic caeca), Open Circulatory system (13-chambered tubular heart, alary muscles), Respiratory system (spiracles, tracheae), Excretory system (Malpighian tubules), and Reproductive system.
अध्याय रूपरेखा एवं प्रगति
11. Epithelial & Connective Tissues
22. Cockroach Morphology & Mouthpart...
33. Cockroach Internal Organ Systems
सम्पूर्ण सैद्धांतिक एवं वैचारिक अध्ययन
1. Epithelial & Connective Tissues
Epithelium: Free surface facing body fluid or environment. Squamous: Flat tiles (blood vessel endothelium, lung alveoli for diffusion); Cuboidal: Cube-like (kidney tubules, secretes/absorbs); Ciliated: Moves particles (bronchioles, fallopian tubes); Compound: Multi-layered for protection against mechanical stress (Skin).
Cell Junctions:Tight Junctions stop substance leakage; Gap Junctions provide rapid cytoplasmic communication of ions and small molecules!
Connective Tissues:Tendon: Dense regular attaching skeletal muscle to bone; Ligament: Attaches bone to bone; Adipose: Subcutaneous fat storage.
2. Cockroach Morphology & Mouthparts
Periplaneta americana (34-53 mm long): Chitinous exoskeleton divided into hardened plates called Sclerites (dorsal Tergites, ventral Sternites joined by flexible Arthrodial membrane). • Head: Formed by fusion of 6 embryonic segments; possesses pair of compound eyes (2000 hexagonal ommatidia producing Mosaic vision with high sensitivity but poor resolution!). • Biting and chewing mouthparts: Labrum (upper lip), paired Mandibles (with teeth), paired Maxillae, Labium (lower lip), and median Hypopharynx (tongue).
Uricotelic Excretion: Conserving water by voiding nitrogenous wastes as insoluble solid uric acid.
स्व-मूल्यांकन अभ्यास (Check Your Understanding)
मूल वैचारिक स्पष्टता की जांच के लिए नैदानिक प्रश्न। पहले स्वयं हल करें, फिर उत्तर देखें।
1
Differentiate between Tendons and Ligaments on the basis of structure and function.
उत्तर एवं व्याख्या देखें
उत्तर: Tendons are dense regular connective tissues consisting of parallel collagen fibers that attach skeletal muscles to bones (tough, inelastic); Ligaments are dense regular connective tissues containing elastic fibers that connect bones to other bones at joints (flexible, elastic). Muscle to bone (Tendon) vs bone to bone (Ligament).
2
What are Cell Junctions? Name the three types of cell junctions found in epithelial tissue and state their functions.
उत्तर एवं व्याख्या देखें
उत्तर: Specialized contact points between plasma membranes of adjacent epithelial cells: (1) Tight Junctions: Prevent substances from leaking across a tissue, (2) Adhering Junctions: Cement neighboring cells firmly together, (3) Gap Junctions: Facilitate cytoplasmic communication by allowing rapid transfer of ions and small molecules. Tight (prevents leak), Adhering (cements), and Gap (communication).
3
Describe the structure and function of the Gizzard in a cockroach.
उत्तर एवं व्याख्या देखें
उत्तर: The gizzard (proventriculus) is a muscular circular organ of the foregut lined by thick circular muscles and covered internally by a thick cuticle that forms six highly chitinous, sharp teeth. It serves to mechanically grind solid food particles into fine powder. Muscular organ with six chitinous teeth for grinding food.
4
What is 'Mosaic Vision' in a cockroach? What are its advantages and disadvantages?
उत्तर एवं व्याख्या देखें
उत्तर: Mosaic vision is vision produced by compound eyes composed of approximately 2,000 hexagonal ommatidia, each receiving a separate partial image of an object. Advantage: It has very high sensitivity, allowing detection of the slightest movement even in dim night light. Disadvantage: It has low optical resolution. Compound eye vision with 2000 ommatidia; high sensitivity, low resolution.
5
Name the excretory organs of a cockroach. What form of nitrogenous waste do they excrete?
उत्तर एवं व्याख्या देखें
उत्तर: The excretory organs are the Malpighian tubules (ring of 100-150 fine yellow filamentous tubules located at the junction of midgut and hindgut). They absorb potassium urate from haemolymph and convert it into solid, insoluble Uric Acid (Uricotelic). Malpighian tubules; excrete solid Uric Acid.
अध्याय का अध्ययन पूर्ण हुआ?
अभ्यास के लिए तैयार?
ऑनलाइन CBT टेस्ट देकर तैयारी का मूल्यांकन करें
झारखण्ड बोर्ड परीक्षा पैटर्न पर आधारित बहुविकल्पीय प्रश्नों का ऑनलाइन टेस्ट दें। तुरंत परिणाम, समय विश्लेषण और प्रत्येक प्रश्न का विस्तृत हल प्राप्त करें।
