BIOLOGY – CLASS 9 ICSE NOTES
Chapter 1: Basic Biology
Biology: Study of living organisms.
Branches: Botany (plants), Zoology (animals), Microbiology
(microorganisms).
Life Processes: Nutrition, Respiration, Growth, Excretion, Reproduction.
Nutrition: Autotrophic (plants), Heterotrophic (animals).
Respiration: Breakdown of food to release energy.
Excretion: Removal of waste substances.
Growth: Increase in size and mass.
Reproduction: Production of new organisms.
Cell: Smallest unit of life.
Tissues: Group of similar cells.
Organ: Group of tissues.
Organ System: Group of organs.
Chapter 2: Cell – The Unit of Life
Cell: Structural and functional unit of life.
Discovery: Robert Hooke (1665).
Types: Prokaryotic (no nucleus), Eukaryotic (true nucleus).
Cell Membrane: Controls entry and exit of substances.
Cytoplasm: Site of cell activities.
Nucleus: Control center, contains DNA.
Mitochondria: Powerhouse of the cell.
Endoplasmic Reticulum: Transport system.
Golgi Apparatus: Packaging and secretion.
Chapter 1: Basic Biology
Biology: Study of living organisms.
Branches: Botany (plants), Zoology (animals), Microbiology
(microorganisms).
Life Processes: Nutrition, Respiration, Growth, Excretion, Reproduction.
Nutrition: Autotrophic (plants), Heterotrophic (animals).
Respiration: Breakdown of food to release energy.
Excretion: Removal of waste substances.
Growth: Increase in size and mass.
Reproduction: Production of new organisms.
Cell: Smallest unit of life.
Tissues: Group of similar cells.
Organ: Group of tissues.
Organ System: Group of organs.
Chapter 2: Cell – The Unit of Life
Cell: Structural and functional unit of life.
Discovery: Robert Hooke (1665).
Types: Prokaryotic (no nucleus), Eukaryotic (true nucleus).
Cell Membrane: Controls entry and exit of substances.
Cytoplasm: Site of cell activities.
Nucleus: Control center, contains DNA.
Mitochondria: Powerhouse of the cell.
Endoplasmic Reticulum: Transport system.
Golgi Apparatus: Packaging and secretion.
