Organisms, Behaviour and Health Year 7: life processes MRS GREN Organisms, Behaviour and Health Year 7: life processes

7A Signs of life - Life on Mars? TEACHER’S NOTES To be used as a starting point for classroom discussion

A simple way of sorting everything on our planet 7A Signs of life - Life on Mars? Serious efforts to discover life on other planets have been going on for many years. If extra-terrestrial beings really were discovered how would scientists decide if they were alive? A simple way of sorting everything on our planet is to divide it into 2 groups – living things and non-living things. But can you tell the difference?

7A Signs of life - Staying alive

There are seven essential life processes. 7A Signs of life – The meaning of life There are seven essential life processes.   To remember these processes meet our little blue woman MRS. GREN… What do all the letters in her name stand for?

Living things need energy to carry out the 7A Signs of life - The meaning of life M = MOVEMENT Living things are able to move about. Animals move from place to place. Plants move by responding to light. R = RESPIRATION Living things need energy to carry out the functions that keep them alive. Respiration is the process by which food is turned into energy. S = SENSITIVITY Living things notice and react to changes in their surroundings. They can respond to light, heat, sound, taste, sight or touch.

Living things grow, increasing in size and complexity. 7A Signs of life - The meaning of life G = GROWTH Living things grow, increasing in size and complexity. R = REPRODUCTION Living things produce offspring. Reproduction continues the survival of each species. E = EXCRETION Living things have to get rid of unwanted waste products. N = NUTRITION Living things need to take in food so that respiration can occur. Nutrients in food help to build, maintain and repair the organism.

But how do living things do all of these? 7A Signs of life - The meaning of life All living things carry out the seven essential life processes. M R S G E N = Movement = Respiration = Sensitivity = Growth = Reproduction = Excretion = Nutrition But how do living things do all of these?