GCSE Biology Year 1 Week 1 - Cells
- Sallyann Clark
- Sep 12
- 4 min read
Updated: Sep 29
“Imagine you could shrink down to the size of a speck of dust and travel inside your own body. What would you see first?”
Introduction
This week you will be introduced to the building blocks of life: cells. You’ll learn the difference between the two main types of cells — eukaryotic cells (animal and plant cells, which contain a nucleus and specialised organelles) and prokaryotic cells (bacteria, which are smaller and simpler, with DNA free in the cytoplasm). You’ll explore the structures that cells share, as well as the unique features found only in plants or bacteria, and begin to understand how these tiny units carry out the essential processes that keep living things alive. By the end of the week, you should be able to draw, label, and describe the functions of key cell parts, and explain how eukaryotic and prokaryotic cells are both similar and different.
What Are Cells? Eukaryotes and Prokaryotes
🔍 What am I learning today?
I can describe the structure of eukaryotic and prokaryotic cells.
I can explain the functions of the main cell organelles.
I can identify similarities and differences between animal, plant, and bacterial cells.
(This is core content for all boards, all tiers.)
🧠 What should I already know?
By now, you should already have a basic idea that:
All living things are made of cells.
Plant and animal cells share some parts but also have differences.
If you need to refresh your memory, watch Science Break: Structure of Cells.
📘 Learning
1. What is a cell?
Cells are the smallest building blocks of life.
Everything alive is made of them – from a tiny bacterium to a giant oak tree.
There are two main types of cell:
Eukaryotic cells (you-kary-oh-tic) → animal and plant cells.
Prokaryotic cells (pro-cary-oh-tic) → bacterial cells.
Think of it like this:
A eukaryotic cell is like a house with separate rooms (organelles) for different jobs.
A prokaryotic cell is like a studio apartment – still works fine, but everything is in one space!
2. Eukaryotic Cells
These are found in animals and plants. They are usually larger (10–100 µm).
Main parts:
Nucleus – the control centre, stores DNA.
Cytoplasm – jelly where reactions happen.
Cell membrane – skin controlling what enters/leaves.
Mitochondria – release energy by respiration.
Ribosomes – make proteins.
Example of an animal cell. Example of a plant cell.
🌿 Plant cells have extra parts:
Cell wall – strong wall of cellulose for support.
Chloroplasts – contain chlorophyll for photosynthesis.
Permanent vacuole – filled with cell sap for structure.
3. Prokaryotic Cells (Bacteria)
Smaller (0.1–5 µm), and simpler – no nucleus! DNA floats in the cytoplasm. Key features:
Cell wall (not cellulose) for support.
Cell membrane – controls movement.
Cytoplasm – chemical reactions.
Plasmids – small extra loops of DNA.
Work through the presentation.
4. Comparing Eukaryotes and Prokaryotes
Feature | Eukaryote (Animal/Plant) | Prokaryote (Bacteria) |
DNA | DNA is present inside the nucleus. | Smaller (0.1–5 µm) Nucleus is absent (DNA free) |
Organelles | Many (mitochondria, ribosomes, etc.) | Few (ribosomes only) |
Reproduction | Many (mitochondria, ribosomes, etc.) | Few (ribosomes only) |
Average Size | Larger (10–100 µm) | Smaller (0.1–5 µm) |
Surrounding | Cell membrane. Cell wall only in plants and fungi | Cell membrane and cell wall. |
Here is a poster you can stick in your journal to help you remember the differences between eukaryotic and prokaryotic cells.
Complete at least two of the tasks below.
Card Games
Print out the cards and play a number of different games with them - snap (when you match a name with a function or a picture). Once you get two, you can claim the third as it appears. Who can get the most sets? Or a memory game where you turn all the cards face down and turn three over each turn. Can you find all the sets?
Cell as a City Map
Draw a cell as if it were a city.
Nucleus = City Hall, Mitochondria = Power Stations, Ribosomes = Factories, Cell Membrane = Security Gates, etc.
Add bacterial features like plasmids = “extra tool sheds.”
3D Model Building
Use craft materials (plasticine, Lego, sweets, or cardboard) to build a plant cell, an animal cell, and a bacterial cell.
Tour Guide Script
Write a short script as if you’re a tour guide inside a cell.
Example: “To your left is the nucleus – our control centre…”
Comic Strip Story
Create a simple comic strip showing what happens if one organelle goes “on strike.”
Example: Ribosomes stop working → no proteins → cell collapses.
Draw
Draw and label all three cells - animal, bacteria and plant.
Conclusion
This week you explored the two main types of cells: eukaryotic cells, such as plant and animal cells, which have a nucleus and specialised organelles, and prokaryotic cells, such as bacteria, which are smaller and simpler. You compared their similarities and differences, and learned the functions of key parts like the nucleus, mitochondria, chloroplasts, and plasmids. You should now be confident in drawing and labelling cells, and explaining how their structures help them carry out life processes.
🔮 Next week, we’ll look at how microscopes allow us to see these tiny cells in more detail, and how to use the magnification formula to measure their true size.
