Basic Requirements
Elementary School
Definition
The essential things a living organism needs to survive, such as food (or sunlight for plants), water, air, and a suitable habitat with space and shelter. If any requirement is not met, the organism cannot survive.
Worked examples
A goldfish in a bowl needs clean water, fish food, oxygen (dissolved in the water), and enough space to swim.
All four basic requirements must be met simultaneously for the goldfish to survive.
A cactus needs sunlight for photosynthesis, water (even if infrequent), air, and sandy soil with space for roots.
Plants have the same basic requirements but obtain food energy differently through photosynthesis.
Common mistakes
- Plants don't need food because they make their own through photosynthesis → Plants need sunlight as their energy source to make food Sunlight replaces food as the energy requirement for plants, but it is still a basic requirement.
- If an organism has most of its basic requirements, it can survive → All basic requirements must be met for an organism to survive Missing even one requirement (like water or air) will cause death — partial fulfillment is not enough.
- Shelter is a basic requirement for all living things → Suitable habitat and space are required; shelter needs vary by organism Some organisms need shelter, others just need the right temperature, pH, or other habitat conditions.
Where you'll use it next
You'll apply basic requirements when studying ecosystems and food webs, learning how environmental changes affect populations, and understanding adaptations that help organisms meet these needs in different habitats.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026