Protists are a special group of living things that belong to a larger category called Eukarya. They have unique features that make them different from other groups of organisms.

1. Cell Structure:
   Most protists are made up of just one cell, but some can have many cells. Their cells are complex and have different parts that are surrounded by membranes.

2. Nutritional Modes:

   • Autotrophic (like algae): These protists can make their own food using sunlight through a process called photosynthesis. In fact, tiny protists called phytoplankton produce about 30% of the oxygen we breathe!
   • Heterotrophic: These protists get their energy by eating other organic material.

3. Reproduction:
   Protists can make more of themselves in two main ways:

   • Asexually, usually by splitting in two (this is called binary fission).
   • Sexually, by joining together in a process called conjugation. This helps them mix genes and stay diverse.

4. Habitat:
   Protists mainly live in water, and they make up a huge part of the life in the oceans—about 90% of all different species found there!

In total, there are around 100,000 different types of protists. This shows just how much variety there is in this kingdom of living things, highlighting their special traits in biology.