IGCSE Coordinated Science: Characteristics Living Organisms

IGCSE Coordinated Science: Characteristics of Living
Organisms

Characteristics of Living Organisms

Functions of living things: MRS GREN
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.

1. Movement
The majority of organisms have the ability to move their entire body, including plants, which can move their stems toward sunlight and their roots toward healthy soil.

2. Respiration
This is the breakdown of food inside a living organism and IT IS VITAL for survival. There are 2 types of respiration
● Aerobic Respiration which involves O2 & glucose breaking down to form CO2 water & energy.

● Anaerobic Respiration which is the incomplete breakdown of food. Happens when there is not enough oxygen. Equation, Glucose & O2 (not enough) to form CO2 and Lactic Acid or Alcohol (depending on the organism) & a little ENERGY.

3. Sensitivity
It is the ability to detect and respond to a stimulus.

4. Growth
It is the permanent increase in size and quantity of cells using materials absorbed from the
environment.

5. Reproduction
It is forming new individuals of the same species either sexual (2 parents) or asexual (1
parent)

6. Excretion
It is removal of harmful products of metabolism. Egestion is the removal of undigested products which haven’t entered the cell.

7. Nutrition
It is the intake of food material from the environment.
● Autotrophic nutrition: Organisms that make their own food such as plants.
● Heterotrophic nutrition: Organisms that need readymade food including herbivores, carnivores & omnivores.