Bacteria, Protists, and Fungi
What do these things look like to you? These are actually little creatures known as bacteria, all are the size of cells, only visible with a microscope. Some of these little creatures can be harmful, and some can be helpful.
Bacteria
Bacteria were probably the first living organisms on earth. They evolved through time, and have evolved to become all the living organisms we see today, from germs to dinosaurs pine trees to Sebastian. All bacteria are unicellular organisms* and are prokaryotes*. Bacteria are divided into two main groups, archaeabacteria and eubacteria.
Archaeabacteria
These bacteria are designed by nature to live in extreme environments. Scientists believe that they were the first creatures to inhabit the earth, as Earth was an extremely hostile planet at the time life appeared for the first time. This group is also a domain and kingdom in the classification system. There are three main types of archaebacteria. The ones that can survive in extreme temperature are the thermophiles. Methanococcus are bacteria that produce methane, a type of gas. Halophiles tend to like living in very salty places.
Eubacteria
Eubacteria include all the common bacteria. Some of them are good, and others can be harmful. These bacteria usually cannot live in extreme environments. The eubacteria are also divided by how they obtain food-as autotrophic of heterothopic. Autotrophs can produce their own food though photosynthesis. Heterotrophs must eat other things to get their energy.
Archaeabacteria
These bacteria are designed by nature to live in extreme environments. Scientists believe that they were the first creatures to inhabit the earth, as Earth was an extremely hostile planet at the time life appeared for the first time. This group is also a domain and kingdom in the classification system. There are three main types of archaebacteria. The ones that can survive in extreme temperature are the thermophiles. Methanococcus are bacteria that produce methane, a type of gas. Halophiles tend to like living in very salty places.
Eubacteria
Eubacteria include all the common bacteria. Some of them are good, and others can be harmful. These bacteria usually cannot live in extreme environments. The eubacteria are also divided by how they obtain food-as autotrophic of heterothopic. Autotrophs can produce their own food though photosynthesis. Heterotrophs must eat other things to get their energy.
Protists
Protists are a kingdom that breaks off of the bacteria. Protists grew more complex than bacteria, and are the link between bacteria and plants and animals. Compared to bacteria, protists are eukaryotes and have organelles (see Cells). These living things can be multicellular(having many cells) or unicellular(consisting of one cell). Protists can look four ways, animal-like, plant-like, or fungi-like, or completely different.
Animal-like
Animal-like protists are heterotrophs. They have the ability to move and must consume other creatures for energy. They move in several ways. One way is used by the amoeba. This involves moving part of the cytoplasm out into a "false foot" called a pseudopod. You can see the pseudopod in the picture below. Animal-like protists also move by using hair-like strands on the cell membrane called cilia. They can also move by using longer, whip-like strands called flagella. Protists may have more than one flagella. They eat primarily by absorbing smaller protists or bacteria. The amoeba does it by surrounding a particle with two pseudopods, trapping it. Paramecium has an oral groove that it uses to scoop up food.
Plant-like
Like plants, they produce their own food through photosynthesis. Some are capable of movement.
Fungus-like
Fungus-like protists serve the same role as normal fungi. These protists include water and slime modes.
Other types
Some protists are crosses between two of the groups above, such as the euglena. It is both plant and animal-like. Usually, euglena use photosynthesis to make food. However, if there's no sun (such as if there is to much algae cover for sunlight to get through or if it's a cloudy day) euglena will eat other protists or bacteria.
Animal-like
Animal-like protists are heterotrophs. They have the ability to move and must consume other creatures for energy. They move in several ways. One way is used by the amoeba. This involves moving part of the cytoplasm out into a "false foot" called a pseudopod. You can see the pseudopod in the picture below. Animal-like protists also move by using hair-like strands on the cell membrane called cilia. They can also move by using longer, whip-like strands called flagella. Protists may have more than one flagella. They eat primarily by absorbing smaller protists or bacteria. The amoeba does it by surrounding a particle with two pseudopods, trapping it. Paramecium has an oral groove that it uses to scoop up food.
Plant-like
Like plants, they produce their own food through photosynthesis. Some are capable of movement.
Fungus-like
Fungus-like protists serve the same role as normal fungi. These protists include water and slime modes.
Other types
Some protists are crosses between two of the groups above, such as the euglena. It is both plant and animal-like. Usually, euglena use photosynthesis to make food. However, if there's no sun (such as if there is to much algae cover for sunlight to get through or if it's a cloudy day) euglena will eat other protists or bacteria.
Fungi
Fungi are decomposers. They break down materials in dead organisms and return the nutrients to the soil. The most popular kind of fungi is the mushroom. Molds, penicillium, and plenty of other microscopic things are fungi. Fungi play a vital role in the food chain as a decomposer, returning nutrients to the soil to restart the cycle.
*= see Living Things