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Structural Organisation in Animals

NCERT Class 11 Biology Chapter 7

Structural Organisation in Animals for Class 11 Biology and NEET: animal tissues, organs and organ systems, and the morphology and anatomy of the frog.

3 topics Updated 8 Nov 2026

For: Class 11 and NEET, unless a topic says otherwise

In the syllabus: NEET Class 11 syllabus

With your textbook

NCERT Biology (Class 11), Chapter 7 “Structural Organisation in Animals”, reprint 2026-27.

Open the official NCERT chapter (PDF, 1.0 MB, ncert.nic.in)

Checked on 19 Oct 2026.

Learn in this order

  1. Animal tissues

    The four types (epithelial, connective, muscle and neural), their kinds and functions, and cell junctions, with labelled diagrams.

    NEET only 12 min read 5 solved examples 10 practice questions

  2. Organs and organ systems

    Levels of organisation from cell to organism, division of labour, and morphology vs anatomy, with examples.

    NCERT Section 7.1 8 min read 5 solved examples 8 practice questions

  3. Frog

    Sexual dimorphism and the organ systems, from digestion to reproduction, with labelled diagrams.

    NCERT Section 7.2 15 min read 5 solved examples 10 practice questions

Key formulas in this chapter

Animal tissues

  • four tissues: epithelial, connective, muscular, neural
  • simple epithelia: squamous, cuboidal, columnar (ciliated, glandular modified)
  • junctions: tight, adhering, gap
  • connective: loose, dense, specialised (cartilage, bone, blood)
  • muscles: skeletal, visceral (smooth), cardiac
  • neural: neurons and neuroglia

Organs and organ systems

  • cell → tissue → organ → organ system → organism
  • tissue: similar cells with intercellular substances
  • organ system: organs working together (digestive, respiratory)
  • heart: epithelial, connective, muscular, neural tissue
  • morphology: external form; anatomy: internal organs

Frog

  • frog heart: 2 atria, 1 ventricle; sinus venosus, conus arteriosus
  • circulation: closed, incomplete double (blood mixes in the one ventricle)
  • respiration: cutaneous in water; buccal, skin, lungs on land
  • excretion: ureotelic; male ureters are urinogenital ducts
  • brain: fore-brain, mid-brain (optic lobes), hind-brain
  • cranial nerves: 10 pairs
  • reproduction: external fertilisation; tadpole; 2500–3000 ova

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