Video Transcript
Which of the following best
describes Euglena? (A) Green, moves by changing body
shape, able to engulf microorganisms. (B) Jellylike, moves using a
flagellum, able to engulf microorganisms. (C) Green, moves using a flagellum,
able to engulf microorganisms. (D) Green, moves using a flagellum,
unable to engulf microorganisms. Or (E) jellylike, moves using a
flagellum, unable to engulf microorganisms.
Euglena is a unicellular, or
single-celled, organism. It is an especially interesting
organism as in spite of being single celled, it is able to photosynthesize much like
a plant would. Remember, photosynthesis is the
process by which some organisms are able to use light energy and simple inorganic
molecules to produce their own food in the form of sugars.
Euglena cells can carry out
photosynthesis thanks to organelles they contain called chloroplasts. The photosynthetic pigments within
these chloroplasts, such as chlorophyll, often make Euglena cells appear
green in color. This means that we can narrow our
answer choices down to (A), (C), or (D).
Most species of Euglena are
also able to obtain nutrition by engulfing food particles and even smaller
microorganisms. This means that they have a backup
method of obtaining nutrients if light levels are low. With this information, we can
eliminate answer choice (D), which suggests that Euglena cells are unable to
engulf microorganisms.
Euglena cells have several
adaptations that allow them to access light efficiently to maximize the amount of
food they make through photosynthesis. For example, Euglena cells
are able to move fairly quickly using whiplike tails called flagella. A single flagella is called a
flagellum. They allow the Euglena cell
to quickly move in the direction of light when they sense it, maximizing the
efficiency of photosynthesis. This means that we have found the
correct answer to this question.
The answer choice that provides the
best description of Euglena is (C): green, moves using a flagellum, able to
engulf microorganisms.
