Plants need water, light, air and the right temperature to grow well. They also take in nutrients from the soil. A plant kept in the dark grows pale and weak. A plant with no water wilts and its leaves droop.
We can find out what plants need with a fair test. Grow two plants that are the same. Give them the same pot, soil and water, but put one in the light and one in a dark cupboard. Change only one thing. After a week, compare their height and colour. The plant in the light will be greener and healthier.
Worked example
Sam gives one plant water and one plant none, and keeps both on a sunny window. What is Sam testing?
- Only one thing is different: the water.
- Everything else is the same.
Answer:So Sam is testing whether plants need water.
Key words
- nutrients
- goodness from the soil that helps a plant grow
- wilt
- droop because of too little water
- fair test
- a test where only one thing is changed
- sunlight
- light from the Sun that plants use to make food
Practise this
New questions every time.
NGSS-referenced: 2-LS2-1