OpenOlympiad
Concept 1 of 9Foundation
Video

What is alive?

Living things share these characteristics (most have ALL of them):

  • Need food and water
  • Grow in size / number of cells
  • Breathe (respire — take O₂, give CO₂ for most)
  • Respond to stimuli (touch, light, sound)
  • Reproduce — make new organisms like themselves
  • Excrete waste
  • Move (even plants bend toward light)
  • Have a life cycle (birth → growth → death)
Example
A car uses fuel, moves, emits smoke — but it doesn't grow or reproduce. Not alive.
Plants don't walk, but they grow, respire, respond to light, reproduce — alive.
💡 Tip:A single trait isn't enough. It's the COMBINATION that marks life.
Prefer a video? Open YouTube search for “characteristics of living things class 6