1. Nutrition and Growth
All living beings need food (nutrition) for growth and development.
- Animals: Eat plants or other animals.
- Plants: Make their own food via photosynthesis (using sunlight, water, air).
- Growth: You cannot wear your clothes from 4 years ago because you have grown. Plants grow from seeds into trees. Non-living things do not show internal growth.
2. Respiration
Respiration is the process of releasing energy from food. Breathing is just a part of respiration (inhaling air and exhaling).
- Animals: We breathe in oxygen and breathe out carbon dioxide. Chest movement indicates breathing.
- Plants: Plants also respire day and night. They take in air through tiny pores on leaves called stomata.
Tip
Did You Know? While plants produce oxygen during the day (photosynthesis), they consume oxygen for respiration continuously (day and night).
3. Excretion
The removal of waste products formed in the body is called excretion.
- Animals: Excrete wastes like urine, sweat, and feces. Sweat also helps cool the body.
- Plants: Excrete excess water through leaves (transpiration) and sometimes store wastes in parts like bark or leaves that eventually fall off.
4. Response to Stimuli
A stimulus is any change in the surroundings (heat, sharp object, light). The reaction to it is the response.
- Example: Stepping on a thorn (stimulus) makes you pull your foot away (response).
- Plants:
- The Touch-me-not (Mimosa pudica) folds its leaves when touched.
- Sunflowers turn towards the sun.
- Roots grow towards gravity/water.
5. Reproduction
Reproduction is producing new individuals of one’s own kind. It ensures the continuity of life.
- Animals: Some lay eggs (birds, snakes, mosquitoes), others give birth to young ones (humans, cats, cows).
- Plants: Mostly reproduce through seeds, but some reproduce through stems (rose) or leaves (bryophyllum).
6. Movement
Living things show movement.
- Animals: Locomotion (moving from place to place).
- Plants: Anchored to soil, but show movements like:
- Opening/closing of flowers.
- Insectivorous plants (e.g., Drosera) closing traps on insects.
- Climbers winding around support.
7. Death
Eventually, all living beings die. If an object shows none of these signs, or stops showing them permanently, it is non-living or dead.