unicellular organisms classified into the Kingdom Protista, and the Phylum Euglenophyta.
All euglena have chloroplasts and can make their own food by photosynthesis. They are not
completely autotrophic though,
euglena can also absorb food from their environment. Euglena usually live in quiet ponds or
puddles. Euglena move by a flagellum (plural ‚ flagella), which is a long whip-like
structure that acts like a little motor.
The flagellum is located on the anterior
(front) end, and rotates in such a way as to pull the cell through the water. Color and label the flagellum
black. It is attached at an inward pocket
called the reservoir. Color and label the
The Euglena is unique in that it is both
heterotrophic (must consume food)
and autotrophic (can make its own
food). Chloroplasts within the euglena trap sunlight that is used for
photosynthesis, and can be seen as several rod-like structures though out the
cell. Color and label the
chloroplasts green. Euglena also
have an eyespot at the anterior end
that detects light, it can be seen near the reservoir. This helps the euglena find bright areas to
gather sunlight to make their food. Color and label the eyespot red. Euglena can also gain nutrients by absorbing
them across their cell membrane, hence they become heterotrophic when light is
not available, and they cannot photosynthesize.
The euglena has a stiff pellicle
outside the cell membrane that helps it keep its shape, though the pellicle is
somewhat flexible and some euglena can be observed scrunching up and moving in
an inchworm type fashion. Color and label the pellicle blue.
In the center of the cell is the nucleus, which contains the cell's DNA
and controls the cell's activities. Color and label the nucleus purple. The nucleolus can be seen within the nucleus. Color
and label the nucleolus pink. The interior of the cell contains a
jelly-like fluid substance called cytoplasm. Color
and label the cytoplasm light
yellow. Toward the posterior of
the cell is a star-like structure, the contractile
vacuole. This organelle helps the
cell remove excess water, and
without it, the euglena could take in some much water due to osmosis that the
cell would explode. Color and label the contractile vacuole orange.