Topic Eleven (1.11): Unicellular organisms

Topics Icon.png Objectives

By the end of this topic you should be able to:

  • describe what a unicellular organism is
  • describe the structure of an amoeba
  • describe the structure of a euglena
  • know the characteristics of living organisms.

Introduction Icon.png Introduction

You are made of trillions of cells, but there are lots of organisms that are only a single cell. Do you know any? There may be as many bacterial cells living on and in you as there are human cells in your body. Don't worry though! They are meant to be there and lots of them have important jobs to help you survive. Isn't Biology amazing?

Interact Icon.png Working through your coursebook

  • Read pages 34–35 of your coursebook. 
  • Use the information to explain the differences between an amoeba and a euglena. Focus on the chloroplasts and the flagellum and their uses. 

COMPLETE – Unicellular Organism Summary Worksheet  Download COMPLETE – Unicellular Organism Summary Worksheet 

  • Living organisms can be said to have features that characterise them as living organisms: 

READ - MRS GREN (Basic Biology) Links to an external site. 

  • Complete the worksheet below. Draw a living organism, or make one up, then describe how it does each of the seven life processes. Use MRS GREN to help you: 

COMPLETE - Life Processes Worksheet (twinkl) [Not available on sample course]

 Review Icon.png Review

Answer the Summary Questions on page 34 of your coursebook, using the information on pages 33-34. If you have time answer the end-of-chapter questions on page 37. For most questions, it is not necessary to answer in full sentences. 

Download and keep this poster, which brings all of the information from this module together. You can use it to help you complete your assignment or in the future to revise your knowledge. 

DOWNLOAD & KEEP - B1 Cells Knowledge Organiser [Not available on sample course]

There is also a glossary for the first Biology chapter:

DOWNLOAD & KEEP - B1 Chapter 1 Glossary [Not available on sample course]

Bridge Icon.png Support activity for this topic

Watch the video below to learn about a different type of diffusion: the diffusion of water.  

This will help you in your practical task. What do you think would happen if you placed a raisin into a cup of syrup for 24 hours? Would it increase or decrease in mass? What would happen if you left a raisin in pure water for 24 hours? Would it increase or decrease in mass? 

Stretch Icon.png Extension activities for this topic

If you'd like an extra challenge:

COMPLETE -  A Day in the Life Extension Activity Download COMPLETE -  A Day in the Life Extension Activity

Download Icon.png Check your answers

CHECK – Unicellular Organism Summary Worksheet – Mark Scheme Download CHECK – Unicellular Organism Summary Worksheet – Mark Scheme 

CHECK - Student Book Answers B1 Chapter 1 (Kerboodle) [Not available on sample course]

Experiments Icon.png Practical

Osmosis is a type of diffusion, so this is a good time to complete Practical 1: Osmosis Download Practical 1: Osmosis from Assignment 01. Any questions you answer or results you note down before you download your assignment can be checked and copied across to your assignment. Remember all you have learnt from Topics 1.0 to 1.5 when planning and carrying out your investigation. Also, download and read the Tips for Investigations Download Tips for Investigations PowerPoint before you start. This first practical has been structured quite clearly for you - as you progress through the course, you’ll have more and more autonomy over your experiment. By the end of Year 9, you’ll hopefully be planning and carrying out your own assessed practicals! Your completed practical questions form part of this module's assignment.