Year8 science lesson on cells

1. © Department for Education, the Government of South Australia, Learning at home, 2022
Year 8
Lesson 9 – cells
Science

2. © Department for Education, the Government of South Australia, Learning at home, 2022
Handy tips for this lesson
View the lesson in slide show mode to use the buttons:
• Use the arrows in the top right corner to go to the next or previous
slide.
• Click the home button to go back to the first slide.
• Some slides have audio. Click on the speaker button to listen.
• Some slides may be interactive. Click the button for extra elements.

3. © Department for Education, the Government of South Australia, Learning at home, 2022
Learning intention
To understand the difference between a unicellular and a multicellular
organism and to describe the basic structures and functions of euglena,
amoeba and paramecium.

4. © Department for Education, the Government of South Australia, Learning at home, 2022
You will need
• A pen and paper.
• A digital device.

5. © Department for Education, the Government of South Australia, Learning at home, 2022
Lesson 7: challenge answers
All organisms are made up of cells.
A unicellular organism is sometimes called a single celled organism.
This means the organism is made up of only one cell. They are microscopic
and cannot be seen with the naked eye. They are mostly aquatic, primitive
and simplest of all the animals.
Organisms that are made up of many cells are known as multicellular
organisms.

6. © Department for Education, the Government of South Australia, Learning at home, 2022
Unicellular organisms
View the unicellular organisms (single-celled organisms) video to
answer the questions on the next slide about the structure and
function of euglena, amoeba and paramecium.
Return to the PowerPoint at the end of the video.

7. © Department for Education, the Government of South Australia, Learning at home, 2022
Questions on unicellular organisms
1. What characteristics do these single-cell organisms share with
multicellular organisms such as insects, birds, chickens and
humans?
2. What do euglena, amoeba and paramecium have in common? How
do they differ from one another?
3. What are 4 ways in which protists ‘function as an entity all to
themselves’?

8. © Department for Education, the Government of South Australia, Learning at home, 2022
Copy and complete the following sentences:
a) Amoeba eat by using the …………………..method.
b) Paramecium eat by sweeping…………………………. to their special mouthparts.
c) Euglena eat by using a mix of ……………………………and………………………………..
d) Amoeba move by shaping themselves into …………………………to……………….
e) Paramecium move about with ……………………called…………….
f) Euglena move by using whip-like……… called ……………………………
g) Amoeba, paramecium, and euglena all excrete waste by using organelles known as
………………
Unicellular organisms

9. © Department for Education, the Government of South Australia, Learning at home, 2022
Review
View this short video to check your answers on
protists.
Return to the PowerPoint at the end of the video.
Source: Biology Figure B23 by CNX OpenStax, https://commons.wikimedia.org/wiki/
File:Figure_B23_02_02.jpg [CC BY 4.0] <https://creativecommons.org/licenses/by/4.0>,
via Wikimedia Commons
Source: Protists/UNC-TV Science on YouTube (Sci NC, 2022)
For your safety, watch this video in the slideshow without accessing YouTube.

10. © Department for Education, the Government of South Australia, Learning at home, 2022
Amoeba
Amoeba are mostly present in ponds, slow-
moving rivers and lakes. They do not have any
definite shape.
Amoeba have pseudopodia that are finger-like
projections that aid in locomotion or movement.
A pseudopodia is also called a false foot.
Source: Amoeba proteus with many pseudopodia by SmallRex,
https://commons.wikimedia.org/wiki/File:Amoeba_proteus_with_many_pseudopodia.jpg
[CC BY-SA 4.0] <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

11. © Department for Education, the Government of South Australia, Learning at home, 2022
Paramecium
Paramecium live in aquatic habitats.
They are typically an oblong organism that
is covered with hairy structures called
the cilia. Paramecium locomotes with the
help of these short hair-like structures.
Source: Paramecium bursaria by Marco Spiller,
//www.flickr.com/photos/marcospiller/7985636788/in/photolist-daEtAU-9EkfcL-hBoMMd-
hfwn4f-haPK4U-9KjrYW-87Ae2P-7TyGLm [CC BY-NC-SA 2.0]
https://creativecommons.org/licenses/by-nc-sa/2.0/

12. © Department for Education, the Government of South Australia, Learning at home, 2022
Euglena
Euglena are present in freshwater
and saltwater. They have both animal
and plant characteristics.
Euglena move using a whip-like tail
called a flagellum. Euglena produce food
in the chloroplasts through the process
of photosynthesis.
Source: Euglena gracilis by Naturalismus,
https://www.flickr.com/photos/naturalismus/4297301229/ [CC BY-SA 2.0]
https://creativecommons.org/licenses/by-sa/2.0/

13. © Department for Education, the Government of South Australia, Learning at home, 2022
Answers – unicellular organism questions
1. What characteristics do these single-cell organisms share with
multicellular organisms such as insects, birds, chickens and humans?
They all have a nucleus in their cells.
2. What do euglena, amoeba and paramecium have in common? How do
they differ from one another?
They move differently: euglena by a flagellum, amoeba by pseudopodia
and paramecium by cilia. Euglena can photosynthesise. Amoeba and
paramecium both take in food.

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Answers – unicellular organism questions
3. What are 4 ways in which protists ‘function as an entity all to
themselves’?
They all can eat, reproduce, move and excrete.

15. © Department for Education, the Government of South Australia, Learning at home, 2022
Answers – unicellular organisms sentence task
a) Amoeba eat by using the surround and digest method.
b) Paramecium eat by sweeping food to their special mouthparts.
c) Euglena eat by using a mix of photosynthesis and surround and digest
method.
d) Paramecium move about with little hairs beating called cilia.
e) Euglena move by using whip-like structures called flagellum.
f) Amoeba, paramecium, and euglena all excrete waste by using organelles
known as vacuoles.

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Challenge
Describe the impact of amoeba on the human body.
How would you get infected by amoeba?

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Key terms
Protists: are single celled organisms that have a distinct nucleus.

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