Group information sheet
Is Euglena a plant or an animal?
The Euglena is unique because it is sort of like a plant and also like an animal. It
is pear shaped. It has a whippy tail called a flagellum that allows it to move
through the water.
The Euglena is different than other protozoan because it has chlorophyll in it, the
substance that plants contain to make their own food. The Euglena is then able
to make its own food like a plant when it is in the sunlight. When it is in darkness,
however, it can get food like an animal. It takes in tiny plants and animals much
like the amoeba and paramecium.
The Euglena has a bright red eyespot which is sensitive to light and helps the
euglena find light.
The Euglena reproduces by fission, splitting lengthwise in two. The flagellum
goes with one part and the other part grows a new flagellum.
When it is too hot or cold for a Euglena, it forms a protective casing called a cyst
around its body that protects it until conditions outside the cyst become better.
Group information sheet
Is Euglena a plant or an animal?
The Structure and Function of Euglena
A typical euglenoid has a pair of flagella, or thread-like structures used in
swimming, at the front end. It also executes a kind of crawling movement by
changing the shape of its body. An eyespot enables it to move towards or away
from light. Most euglenoids contain several chloroplasts, which gives them a
greenish colour and enables them to photosynthesise. Some euglenoids feed by
taking up dissolved substances, and a few can ingest larger materials such as
other euglenoids. They reproduce by binary fission, or dividing in two, and there
is little evidence of sexual reproduction.
Pupil task sheet
Is Euglena a plant or an animal?
 Read the passage and follow the instructions to complete the diagram.
Euglena are 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
twirls in such a way as to pull the cell through the water.
It is attached at an inward pocket called the reservoir.
Colour the reservoir grey and the flagellum black.
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 throughout the cell.
Colour 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.
Colour 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 photosynthesise.
The Euglena has a stiff pellicle outside the cell
membrane that helps it keep its shape, though the
pellicle is somewhat flexible.
Colour the pellicle blue.
In the center of the cell is the nucleus, which contains
the cell's DNA and controls the cell's activities. The
nucleolus can be seen within the nucleus.
Colour the nucleus purple, and the nucleolus pink.
The interior of the cell contains a jelly-like fluid
substance called cytoplasm.
Colour 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.
Colour the contractile vacuole orange.
Group information sheet
Instructions to learners
1. Read the passage above and complete the diagram.
2. Each learner places each evidence card in the column in which they think the
statement belongs.
3. In pairs, you must give reasons for putting the evidence cards in one column
over another column.
4. In groups of four, you must argue whether the Euglena is a plant, an animal,
both or neither. A claim is only valid if there is evidence for it.
5. During the plenary session, groups must report on their discussions and
indicate the outcome of their group’s exploration. They must use the
evidence cards to substantiate (synthesise evidence) their claims.
6. Each individual must submit an account of his/her claim and counter-claim
with evidence and counter-arguments.
You may wish to consider the following questions to help you begin to decide
whether Euglena is a plant or an animal:
1.
2.
3.
4.
5.
6.
7.
8.
9.
1.
2.
Are Euglena unicellular or multicellular?
What Kingdom do Euglena belong to? What Phylum?
What organelle carries out photosynthesis?
On which end is the flagellum located?
Define autotrophic.
Define heterotrophic.
Describe the two ways in which the Euglena get their nutrients.
What is the eyespot used for?
What is the function of the nucleus?
What is the function of the contractile vacuole?
What would happen if the cell did not have this organelle
Group information sheet
Euglena Evidence Cards
Euglena has two outer layers.
Euglena contains chloroplasts.
Euglena has a nucleus.
Euglena is a single cell.
Euglena can absorb food
from its surroundings.
Euglena confused early scientists.
Euglena is normally green.
Euglena can make its own food.
Chloroplasts enable a cell
to photosynthesise.
The nucleus contains DNA and
controls the cell activities.
Euglena swims through water.
A vacuole controls the amount of liquid
in a cell.
Euglena has a vacuole.
Euglena is light sensitive.
Euglena contains cytoplasm.
Euglena can change its shape.
Euglena live in ponds and puddles.
Euglena is temperature sensitive.
Euglena has a pair of flagella
used in swimming at the front end.
There are more than two
classification groups.
Group information sheet
Complete the following worksheet
EUGLENA
Plant?
Evidence that
suggests Euglena
is a plant cell
Evidence that
suggests Euglena
is an animal cell
Animal?
Evidence that
suggests Euglena
is a plant or
animal cell
Evidence that
suggests Euglena
is neither a plant
cell nor an animal
cell
In pairs
Euglena is a ……………………….
because …………………………………………………………………………………..
………………………………………………………………………………………………
………………………………………………………………………………………………
In my Group
Euglena is a ……………………….
because …………………………………………………………………………………..
………………………………………………………………………………………………
………………………………………………………………………………………………
Pupil task sheet
Is Euglena a plant or an animal?
________________
Name
This task will assess your ability to think scientifically in drawing a conclusion.
1. Having considered the arguments, do you think Euglena is a plant or animal?
________________________________________________________________
2. Explain below how you came to your decision. Identify the evidence you used
and explain why it may have been difficult to decide, both for and against.
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Level achieved:  Developing
( Consolidating
To achieve a higher level you could:
( Secure
Pupil assessment
sheet
Writing across learning
Criteria
Excellent Good Satisfactory Needs
improvement
Almost all of my spelling is correct.
I can use a range of punctuation
accurately.
I can use paragraphs confidently and
accurately.
I can organise ideas appropriately and
logically.
I can use a range of linking words e.g.
furthermore, moreover, whereas, and
similarly etc.
I can use nouns, pronouns and tenses
accurately and consistently.
Thinking scientifically – drawing conclusions
Success criteria to demonstrate your ability to think scientifically in drawing a
conclusion as to whether Euglena is a plant or an animal.
You may have:
Developing
Made a claim or a counter-claim but not presented evidence to
support your argument.
Developing
Made a claim(s) with supporting evidence but not presented
any evidence against your claim.
Consolidating Made a claim and counter-claim with evidence but without any
counter-argument.
Secure
Written a detailed account with claims and counter-claims with
evidence but without any counter-argument (evidence against).
Secure plus
An account with claims and counterclaims supported with
evidence and with counter-arguments.