Cells summary

1. HOW CELLS WERE DISCOVERED The microscope was invented about 300 years ago. It is an instrument we use to see the cells.

Scientist started studying living things under microscopes and realize that all animals and plants are made up of many tiny parts called cells.

2. WHAT ARE CELLS? Cells are like tiny sacks of liquid. Cells are living things. They carry out the life processes of nutrition, reproduction and sensitivity.

They differ in shape, size and tasks.

3. PARTS OF CELLS. Cells have 3 main parts: Membrane: is a covering which surrounds the cell and separates it from the outside.

Nucleus: is the part which controls the functions of the cell Cytoplasm: is the liquid between the nucleus and the membrane.

It contains lots of organelles that carry out different functions.

4. ANIMAL AND PLANT CELLS. Animal cells: they can be different shapes. Their shapes are very irregular.

Plant cells: are usually bigger and have a regular shape. Have a hard cell wall around the membrane. They have special organelles called chloroplasts to carry out photosynthesis.

5. UNICELLULAR AND MULTICELLULAR LIVING THINGS. All living things are made up of cells.

Animals and plants are formed by a large number of cells → multicellular.

Other living things are made up of a single cell → unicellular.