CELLS All living things are made of cells which are either unicellular eg bacteria and yeast or multicellular organisms. Microscopes are used to study cells, light microscopes can magnify about 1500 times and an electron microscope magnifies 40,000 to 500,000 times.

Nucleus controls what the cell does. Animal cells Complex organisms like you are made up of many different kinds of cells. Cell membrane holds the cell together and controls what goes in and out of the cell. Nucleus controls what the cell does. Contains the DNA (with genes ) Cytoplasm is where all the chemical reactions take place.

Plant cell Nucleus controls what the cell does. Contains the DNA Plant cells are very special as they can trap sunlight and store the energy as “plant food” Plant cell Cell wall made of cellulose, gives support for the cell Vacuole containing cell sap, a solution of sugar and salts. Nucleus controls what the cell does. Contains the DNA Cell membrane holds the cell together and controls what goes in and out of the cell Chloroplasts containing chlorophyll for photosynthesis Cytoplasm is where all the chemical reactions take place.

A cell wall A vacuole Comparing animal cell and plant cells But only plant cells have:- Both cells have:- A nucleus A cell wall Cytoplasm A vacuole Cell membrane 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.

Cells Tissues Organs Organisms Systems

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.

Organ- Brain Nervous system Nervous tissue Nerve cell