characteristics of living organism
Characteristics of Living Organisms
Nutrition
Process of obtaining food for energy, growth, repair, and maintenance.
Provides raw materials for building new cells and energy for activities.
Types:
Autotrophs: Make their own food (e.g., plants) via photosynthesis using sunlight, water, and carbon dioxide.
Heterotrophs: Depend on other organisms for food (e.g., humans, animals).
All organisms depend directly or indirectly on plants for nutrition.
Respiration
Process of breaking down food inside cells to release energy.
Energy is used for movement, growth, repair, reproduction, and body functions.
Types:
Aerobic respiration: Uses oxygen, releases more energy.
Anaerobic respiration: Occurs without oxygen, releases less energy.
Continuous process, even during rest or sleep.
Growth and Development
Growth: Permanent increase in size or number of cells through cell division.
Development: Changes in form, structure, and function as an organism matures.
Living organisms grow from inside, unlike non-living objects.
Movement
All living organisms exhibit movement.
Types:
External movement: Walking, running, flying, swimming.
Internal movement: Blood circulation, food transport, movement of substances in cells.
Even plants move, e.g., bending toward light or roots growing downward.
Sensitivity (Response to Stimuli)
Ability to detect and respond to changes in the environment.
Stimuli include light, heat, sound, touch, chemicals, or pain.
Helps in protection, survival, and adaptation.
Excretion
Process of removing harmful waste products from the body.
Examples: Carbon dioxide, urea, excess water, salts.
Maintains internal balance and prevents toxic buildup.
Reproduction
Process of producing new individuals of the same species.
Ensures continuity of life.
Types:
Sexual reproduction: Two parents involved.
Asexual reproduction: One parent involved.
Necessary for species survival, though not for individual survival.
Metabolism
Sum of all chemical reactions in the body.
Anabolism: Building complex substances for growth and repair.
Catabolism: Breaking down substances to release energy.
Fundamental to all life processes; life cannot exist without metabolism.