Algae are simple, plant-like organisms that can make their own food through photosynthesis. They don’t have true roots, stems, or leaves like higher plants, but they still play a massive role in nature. Algae can be as tiny as single cells (like phytoplankton) or as large as seaweeds.

Key Points You Need to Know

• Definition: Plant-like organisms that do photosynthesis.
• Structure: No roots, stems, or leaves.
• Sizes: Microscopic (phytoplankton) - Large seaweeds (kelp).
• Habitat: Mostly aquatic - freshwater, seawater, or moist surfaces.
• Importance: Provide oxygen and form the base of aquatic food chains.