1. Bell ringer
Complete the revision questions Pt 1: Cell structure

2. Cell essays – good practice
Make sure for each organelle you state one of the MAIN functions
Be careful not to confuse Golgi apparatus and ER
The centrosome is involved in mitosis, not the centrioles.

3. Lesson objectives 1.1 e,f
outline key structural features of typical prokaryotic cells
Compare and contrast the structure of typical prokaryotic and eukaryotic cells
Outline key features of viruses

4. Cell Organisation: Prokaryote Cell Eukaryote Cell
Prokaryotes have a simple structure and probably the first life on Earth!
Eukaryotes probably evolved from prokaryote cells around 1000 million years ago!

5. Tasks: Prokaryotes and Viruses
Draw a diagram of a typical bacterium. Identify structure that are always present vs. additional structures
Make a table comparing eukaryotes and prokaryotes including the following aspects: size, cell wall, nucleus, genetic material, mitochondria, chloroplasts, ribosomes, endoplasmic reticulum, cytoskeleton, cilia and flagella, slime capsule
Draw a simple diagram of a virus (key words: protein coat and DNA/RNA)
Would you describe viruses as "living organisms"? Explain your answer. (Make sure to show arguments for both sides before coming to an conclusion!

6. made of cellulose/lignin in plants, made of chitin in fungi
Structure
Eukaryotic cell
Prokaryotic cell
Size
 40 µm
0.5 – 5 µm
Unicellular or multicellular
Mostly multicellular
Unicellular
Cell wall
made of cellulose/lignin in plants, made of chitin in fungi
Made of murein a peptidoglycan (almost always present)
Nucleus
 yes No
Genetic material
DNA in form of chromatin/chromosome s (associated with proteins) within nucleus
Naked circular DNA in the cytoplasm, sometimes plasmids are present
mitochondria no
chloroplasts
 in plant cells
 no
ribosomes
 yes (80s)
Yes (70s)
Endoplasmic reticulum
cytoskeleton
yes
Cilia and flagella
 in animal cells
Slime capsule
Most cells

7. Viral structure

8. Are viruses alive? Yes No Cells X Reproduce
Cannot reproduce by themselves
Use energy
Response to environment
Can interact with cells
Contact with cells is not active and only based on chemical makeup of virus and it’s environment
Universal genetic code
Evolution
Grow and develop
Homeostasis

9. Viruses:
Most viruses found in animal cells and those attacking bacteria (bacteriophages) have the nucleic acid DNA.
Cause a variety of infectious diseases in humans, animals and plants.
Extremely small and can only be seen with an electron microscope.
Other animal and plant viruses contain RNA.
Can be called ‘non cells’ as they have no cytoplasm, organelles and no chromosomes.
A widely studied virus is T2 phage, a bacteriophage, which infects the bacterium Escherichia coli (E. coli).
Exist as an inert ‘viron’ when outside a cell.
Take over a cell’s metabolism and multiply within the host cell.
Each virus particle has a core of nucleic acid surrounded by a protein coat called the capsid.

10. Test your understanding
Revision questions - viruses

11. Plickers

12. Understanding the mark scheme
Peer mark your homework

13. Kahoot