The Bare Basics

• All organisms are made up of units called cells.
• There units are surrounded by a cell membrane that controls what enters and leaves.
• The Nucleus is the control centre of the cell.
• Plant cells contain chloroplast that make food by photosynthesis.

This diagram shows a type of animal cell.

Most cells are specialised for the job they perform. For example the diagram above illustrates a sperm cell, the job of this cell is to join with, or fertilise the oveum, to help it do this the tail enables it to swim towards it.

Living organisms are different to non living material because they carry out seven vital processes, these are often called characteristics of living organisms. The ability to respond to changes occurring around them is called sensitivity.
Excretion is the ability to remove waste products that ave been produced by the organism and the release of energy from food molecules is called respiration.
Animal and Plant Cells
Although plants and animals have many things in common, there are four main differences:

• Plant cells have a strong cell wall made of cellulose, animal cells do not.
• Plant cells have a large permanent vacuole containing cell sap, vacuoles in animal cells are small and temporary.
• Plant cells may contain chloroplasts contailing chlorophyll for photosynthesis. Animal cells never contain chloroplasts.
• Animal cells store energy as granules of glycogen but plants store starch.

Plant and animal cells have many smaller structures int he cytoplasm. These can be seen by using an electron microscope.