We can place all things into three groups:
Used to Be alive
eg wood, fossil, paper
Living things are able to do several things a non-living thing may not be able to do like move, grow, reproduce and feed .
There are seven processes that are carried out by all species of animals and plants.
These can be remembered by thinking of the word MRS NERG
(You may have learnt it as MRS GREN). Look at the first letter of each life process.
What it means
|Movement||Going from one place to another.Animals usually move their whole body from one place to another.Leaves turn towards the light. Roots grow down into the soil.|
|Reproduction||Producing new plants or animals.Animals have babies.New plants grow from seeds.|
|Sensitivity||How things react and respond to what is happening around them eg plants
turning and moving towards the light oryour mouth watering when you smell something good to eat.
|Nutrition||Taking in food. Food is needed to supply energyGreen plants can make their own food using sunlight, carbon dioxide and water.
Animals eat plants or other animals.
|Excretion||Getting rid of waste substances.eg Plants and animals excrete (get rid of) carbon dioxide.|
|Respiration||Releasing energy from sugar or starch. See Respiration
Plants and animals turn food into energy
We need energy for many things including movement, growth and warmth
|Growth||Getting bigger. Seedlings grow into bigger plants.babies grow into adults|
Respiration is a chemical reaction that provides all life with energy
sugar + oxygen → carbon dioxide + water + energy
All living organisms, animals and plants, carry out respiration
Normal (aerobic) respiration requires oxygen and glucose (a kind of sugar)
The sugar reacts with the oxygen releasing energy.
Carbon dioxide and water which are released as waste products
Respiration is the exact reverse of photosynthesis.
Respiration and photosynthesis are both chemical reactions and have similar equations.
Learn them both carefully but DO NOT MUDDLE THEM UP.
See “Words and facts often muddled“