Protists and their characteristics lesson for kids: 1st, 2nd, 3rd, 4th, 5th, 6th and 7th grades biology lesson.
There are many kinds of living things in this world, but right now we are going to focus on protists. Protists are usually unicellular (one-celled) microscopic organisms, meaning they are so small that you can’t see them unless you use a microscope. Unlike bacteria, though, protists have nuclei that contain their DNA (the code that tells the cell how to do just about everything it does), and have many more special parts to do specific jobs.
Some protists are multicellular (many-celled). They have cells that are all look and act pretty much the same. That’s different from your body, which is divided into tissues, groups of cells that each look different from the cells of other tissues.
As said before, every protist cell has a nucleus, but that isn’t the only thing that makes up their cells. Just like your bodies have organs that do different jobs like breathing and eating, protist cells have organelles. Most protists have organelles called mitochondria (singular: mitochondrion), which use oxygen to give the cell the energy it needs to keep living and do everything it needs. Some special protists can make energy without oxygen, though, and their cells use organelles called hydrogenosomes to make energy.
It isn’t always easy to know just by looking that something is a protist. Kelp, a kind of seaweed, is actually a protist even though it looks and acts like a plant. It, like other plant-like protists, is able to make its own food light as a source of energy; just like a plant does. It even has chloroplasts in its cells, the same kinds of organelles plants have, and these chloroplasts are where protist cells convert light energy into a form that they can use for themselves.
Some protists are like animals, too. Just like animals can move around and get the food they want, or move away from danger, some protists, even unicellular ones, can move by paddling through water with tiny hairs, using tails to swim like fish, or oozing and pulling themselves along.
Another thing about protists is how they reproduce. Most of them copy themselves by splitting their cells into two or even lots of little baby cells. This is called asexual reproduction. Others have complex life cycles, with a stage of sexual reproduction. In this stage, the protist cells split into either male or female cells. Then, a male cell will join together with a female cell to make a new generation of protists.
As we have seen by now, there are lots of different kinds of protists. The plant-like ones are called algae (singular: alga), and there are even amoebas that move around and eat like animals do, and slime molds, which are sort of like fungi. Smile molds are special because they can be very big, even many feet wide, but still only be one cell, sometimes with lots of nuclei in them.
Protists are diverse organisms. They may not be as complex as plants or animals, but they still manage to survive in lots of interesting ways!