Amoeba (genus)
There are many species in this genus. They are very difficult to tell apart.
Nikon Microscopy U
Amoeba (genus)
There are many species in this genus. They are very difficult to tell apart.
Nikon Microscopy U
Amoebas, like all
protists, are single-celled organisms. Cells
are the building blocks for all life forms. "Single-celled"
means that amoebas have only one cell for their entire body.
A human body has more cells than you can count. The inside of an amoeba is a jelly-like fluid called cytoplasm. Bits of food and other materials float around in the protoplasm. Amoebas are so tiny that
you need a microscope to see them. They live in water,
including lakes, ponds, streams, rivers, and puddles. Some
can even live in the bodies of animals. The most important part
of an amoeba might be the pseudopod (pronounce it
"sudopod"). The psuedopod is used to
help the amoeba move, and also to eat. It is a part of the
amoeba's body that it can stretch out and pull itself with.
Or, to eat, the amoeba stretches out the pseudopod,
surrounds a piece of food, and pulls it into the rest of the
amoeba's body. Amoebas reproduce (make
more amoebas) by a process called binary fission. This means
that one amoeba can split in half and make two identical new
amoebas. Amoebas eat
algae,
bacteria, other protozoans, and tiny particles of dead plant
or animal matter. They spend most of their
time attached to the bottom or to plants. Sometimes they
float freely in the water. They do this as a "swarm." All
the amoebas of the same species will unattach from the
bottom or plants and float around until they land in a new
place and re-attach. Animals that eat amoeba
include plankton
feeders, such as mussels and water fleas. Copyright, James
Etrarts
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Relationships in Nature:
Bacteria
Relationship to Humans:
Amoebas are helpful when they control algae in ponds, lakes, and streams. They also provide small animals with food. Amoebas are a problem when they live in unhealthy areas, such as places with raw sewage. They can sometimes make people ill when they get inside their bodies. Dysentary is an example of illness caused by amoebas.