CELLS

1. All living things are made of cells which are either unicellular eg bacteria and yeast or multicellular organisms.

2. Microscopes are used to study cells, light microscopes can magnify about 1500 times and an electron microscope magnifies 40,000 to 500,000 times.

Animal cellsComplex organisms like you are made up of many different kinds of cells.

Nucleus controls what the cell does.

Contains the DNA (with genes )

Cytoplasm is where all the chemical reactions take place.

Cell membrane holds the cell together and controls what goes in and out of the cell.

Plant cellPlant cells are very special as they can trap sunlight and store the energy as “plant food”

Nucleus controls what the cell does. Contains the DNA

Cytoplasm is where all the chemical reactions take place.

Cell membrane holds the cell together and controls what goes in and out of the cell

Chloroplasts containing chlorophyll for photosynthesis

Vacuole containing cell sap, a solution of sugar and salts.

Cell wall made of cellulose, gives support for the cell

Comparing animal cell and plant cells

Both cells have:-

A nucleus

Cytoplasm

Cell membrane

But only plant cells have:-

A cell wall

A vacuole

Chloroplasts

Remember there are lots of different kinds of animal and plant cells but all of them have the above features

CELLS AND ORGANISMS

• 1. Structures within a cell are called organelles.

• There is division of labour between cells.

• Similar cells are grouped to form tissues.

• An organ contains tissues working together.

• An organ system contains organs working together.

CellsTissues

Organs

Systems

Organisms

Example

1. Organelles make up nerve cells ( neurons) , which make up nervous tissues, which make up the organs brain and spinal cord, which make up nervous system.

Nerve cellNervous tissue

Organ- BrainNervous system