Living organisms have certain life processes in common. There are seven things that they need to do to count as being alive. the phrase MRS GREN is one way to remember them. These letters stand for movement, respiration sentivety growth reproduction excretion and nutrition.
It can be easy to tell if something is living or not. A teddy bear might look like a bear but it can not do the same thing it needs to be able to do to count as being alive all it can do is sit down and do nothing.
On the other hand a car can move. It gets energy from petrol (like nutrition and respiration) it might have a car alarm so it has senses.
Movement is one of the conditions of a living organism. Sometimes it is not that obvious. An example of this is plants such as an apple tree.
Respiration, or being able to breathe, is the next condition. Some living things breathe oxygen in the air using lungs whilst others use lungs to breathe in water, e.g. fish.
Sensitivity is all about being able to detect changes in the environment around the living organism. Examples of this include whiskers on cats and antennae on insects.
The G in MRSGREN stands for growth and all living things do this even if it is really slow. One of the slowest growing things is a coral reef like in Australia.
All living things are capable of reproduction and different species produce different numbers of offspring. Frogs lay a lot of eggs but humans usually have less than five babies.
Another thing that living things need to do is get rid of waste materials and this prosess is called excretion. This comes in different forms such as CO2 from breathing and urine in pee.
Nutrition is about obtaining and consuming food. It is the final letter in the mnemonic MRSGREN. This means that all living things have to eat or they will die. For example, I need to eat a lot of potatoes!
In conclusion, it is well know that the diversity of life on Earth is massive. You have to do things to stay alive or you will face death.
