What you need to know

Reflections and Exam tips

Cells and living things

A living thing is not just one mass of solid (or liquid).

Living things are called organisms. Organisms are made of tiny subunits called cells (boxes). A cell is the basic buliding block of all living things.

There are 2 big groups of living things: Plants and animals, each group is made up of its own kind of cells. So there are Plant cells and Animal cells. Since plants and animals are different, plant and animal cells will also be different.

An animal cell

A plant cell

There are also other living things such as bacteria and amoeba. These have their own kind of cell.

Bacteria

Bacteria are the simplest living organisms, so their cells are not advanced- This means that they have fewer structures in them

The most important feature of bacteria is that they do not have a nucleus- Their DNA (genetic material) lies naked in the cytoplasm. They also have a cell wall like plant cells but it is made of a different chemical (not cellulose as in plant cells)

Amoeba

Amoeba are single celled organisms which are similar to animal cells. Unlike animals, each amoeba cell is capable of doing all the life processes.

Diagram of Amoeba

Euglena

Euglena is an interesting biological specimen as we do not know whether to say it is a plant or an animal.

Euglena:

• Contains chloroplasts, so it photosynthesises like a plant
• Has a cell wall
• It can move on its own

So is it a plant or an animal?

Picture of Euglena

For a start: make sure you can name parts of each cell.

To secure, you need to explain the job of each part of the cell

To advance, make sure you can compare all these cells.

Look carefully at the diagrams of plant and animal cells. Write down a list of their differences.