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Biology · Class 10 · Chapter 13: Support and Movement

8 min

Key points

Support and movement are essential life processes — plants need support against gravity and wind, animals need movement for food and survival
Skeleton provides framework, protects internal organs, gives shape to body, and provides attachment sites for muscles
Hydrostatic skeleton found in earthworms uses body fluid pressure for support and movement
Exoskeleton in arthropods like insects and crustaceans provides external hard covering made of chitin
Endoskeleton in vertebrates is internal framework made of bones and cartilage
Human skeleton has 206 bones divided into axial skeleton (skull, vertebral column, rib cage) and appendicular skeleton (limbs)
Joints allow movement between bones — ball and socket joints allow movement in all directions, hinge joints allow movement in one plane only
Muscles work in antagonistic pairs — when one contracts, the other relaxes to produce movement
Tendons attach muscles to bones while ligaments connect bones to bones at joints

Definitions

Skeleton: The framework of hard or rigid parts that provides support and shape to the body of an organism
Hydrostatic Skeleton: A type of skeleton found in soft-bodied animals where body fluids under pressure provide support and enable movement
Exoskeleton: An external hard covering that provides support and protection to the body, found in arthropods like insects and crustaceans
Endoskeleton: An internal framework of bones and cartilage that provides support to the body, found in vertebrates
Joint: The place where two or more bones meet and are held together by ligaments

Worked example

Define bone and cartilage. Compare any three characteristics of bone and cartilage. (6 marks)

Bone: Bone is a hard connective tissue composed of calcium phosphate and collagen fibers that provides structural support to the body. Cartilage: Cartilage is a flexible connective tissue made of chondrin that provides cushioning and smooth movement at joints. Comparison: (1) Hardness - Bone is hard due to calcium salts, Cartilage is soft and flexible (2) Blood supply - Bone has rich blood supply, Cartilage has no blood supply (3) Growth - Bone grows throughout life, Cartilage has limited growth capacity

Common mistakes

Students confuse exoskeleton with endoskeleton — remember exo means external, endo means internal
Mixing up tendons and ligaments — tendons connect muscle to bone, ligaments connect bone to bone
Forgetting to mention both axial and appendicular skeleton divisions in human skeleton questions
Not stating exact number of bones (206) in human adult skeleton
Confusing ball and socket joints with hinge joints — ball and socket allows movement in all directions

Quick recap

Support and movement involves skeletal system (206 bones providing structure), muscular system (skeletal, cardiac, smooth muscles), and joints (immovable, slightly movable, freely movable). Bones are hard connective tissue with calcium phosphate, cartilage is flexible connective tissue with chondrin. Muscles contract to produce movement, with skeletal muscles being voluntary and striated, cardiac muscles involuntary and striated, smooth muscles involuntary and non-striated.

Generated by AI from Sindh Textbook Board material; review state: ai_unreviewed. MCQs, past-paper references and examiner notes are held back until a teacher has checked them.