Tiny food-makers
Microalgae make food and oxygen in sunlight.
The oxygen we breathe
Trees and other plants make oxygen. But there are tiny, plant-like organisms in water that make oxygen too. They are microscopic.
How much of Earth's oxygen do you think these tiny organisms produce?
What this lesson covers
The idea
Microalgae are microscopic plant-like organisms that make their own food using sunlight, releasing oxygen — more than half of Earth's supply — and serving as food for many aquatic animals.
The oxygen we breathe
Trees and other plants make oxygen. But there are tiny, plant-like organisms in water that make oxygen too. They are microscopic.
How much of Earth's oxygen do you think these tiny organisms produce?
- More than half of it
- A very small part
- None
A pond in the sun
Turn the sunlight on and watch the microalgae. Then feed the fish.
Food and oxygen
Microalgae are microscopic plant-like organisms. They make their own food using sunlight, releasing oxygen: more than half of Earth's oxygen supply. They are also food for many aquatic animals.
- Microalgae | Fact
- Size | Microscopic
- Where | Water, soil, air and even on trees
- Food | Make their own, using sunlight
- Gas released | Oxygen: more than half of Earth's supply
- Role in water | Food for many aquatic animals
Notes
Microalgae are microscopic plant-like organisms that make their own food using sunlight, releasing oxygen (more than half of Earth's supply) and serving as food for many aquatic animals.
Check yourself
What do microalgae need to make their own food?
Which gas do microalgae release?
How are microalgae useful to many aquatic animals?
- Sunlight — correct. Yes. They make their own food using sunlight.
- Milk. Microalgae make their own food. They do not need milk.
- Salt. Salt is a preservative. Microalgae use sunlight to make food.
- Oxygen — correct. Yes. They produce more than half of the Earth's oxygen supply.
- Methane. Methane is in biogas. Microalgae release oxygen.
- Nitrogen. Rhizobium trap nitrogen. Microalgae release oxygen.
- They are a source of food — correct. Yes. Microalgae serve as a food source for many aquatic animals.
- They hunt and eat the animals. Microalgae make their own food using sunlight. They are eaten by many aquatic animals.
- They have nothing to do with aquatic animals. Many aquatic animals eat microalgae.