1. Lesson 1: Cells and Infection
Chapter 1
Lesson 1: Cells and Infection
4th Grade Science

2. What are Cells? Cell Organism The smallest unit of living matter.
Any living thing that can carry out its life on its own.

3. Cells to Organisms Tissue Organ Organ systems
A group of similar cells that work together at the same job.
Organ
A group of tissues working together to do a certain job.
Organ systems
A group of organs that work together to do a certain job.
Organelle > Cell > Tissue > Organ > Organ System > Organism

6. What causes infection?
Virus – Small things that take over cells and force them to make copies of it (The Flu)
Bacteria – Small living things that cause infections (Food Poisoning)
Fungus – Infection caused by fungus (Athlete’s Foot)
Parasite – A living thing that invades another (Tape Worm)

7. Bacteria is everywhere
There are over a million bacteria in one cm3 of water
Millions and millions of bacteria live on your body without doing any harm.