Characteristics of Living Organisms
iGCSE Biology
Learning Objectives
Characteristics of Living Things
Life Processes
• If something is alive it will carry out all
of the seven life processes.
– Movement
– Respiration
– Sensitivity
– Growth
– Reproduction
– Excretion
– Nutrition
Characteristics of Living
Things
• M is for movement
• Movement is an action by an organism
or part of an organism causing a
change in position or place
Examples
– Animals move to find food, shelter or a
mate.
– Plants do not move in the same way as
animals but move towards sunlight.
Characteristics of Living
Things
• R is for reproduction
• Reproduction is a process that makes
more of the same kind of organism
Examples
– Animals lay eggs or have babies.
– Seeds from plants grow into new plants.
Characteristics of Living Things
• S is for sensitivity.
• Sensitivity is the ability to detect and
respond to changes in the internal or
external environment.
• The organisms detect or sense stimuli in the
in the internal or external environment and
to make appropriate responses
Examples
– Animals find their way using their sense
organs such as the eyes or skin.
– Plants don’t have sense organs but do
respond to gravity and light.
Characteristics of Living
Things
• G is for growth
• Growth is growth is the permanent
increase in size and dry mass.
– Animals stop growing when they reach
adult size.
– Plants grow throughout their lives.
Characteristics of Living
Things
• R is for respiration
• Respiration as the chemical reactions
in cells that break down nutrient
molecules and release energy for
metabolism
– Respiration is the release of energy from
food.
– This usually needs oxygen.
Characteristics of Living
Things
• Respiration is the most important
process. No organism is alive unless it
can release energy by respiration
Characteristics of Living Things
• E is for excretion
• Excretion as removal from of the waste
products of metabolism and substances
in excess of requirements
– All living things produce waste.
– Animals excrete through their lungs,
kidneys and skin.
– Plants shed their leaves in autumn
Characteristics of Living
Things
• N is for nutrition
• Nutrition as taking in of materials for
energy, growth and development
• Plants require light, carbon dioxide,
water and ions;
• Animals need organic compounds
and ions and usually need water
Characteristics of Living
Things
– All living things need food for energy,
growth and repair.
– Animals have to find their own food
and eat plants and other animals.
– Plants make their own food by the
process of photosynthesis.
Plenary
Question 1
Question 2
Question 3
Question 4
Question 5
Questions
Write down the name for the following definitions:
a) Taking in of nutrients which are organic substances and mineral ions for
energy and growth.
Nutrition
__________________________________________________________________
b) Chemical reaction that break down nutrient molecules in living cells to
release energy.
Respiration
__________________________________________________________________
c) Ability to detect or sense changes in the environment and make a
response.
Sensitivity
__________________________________________________________________
d) A permanent increase in size and dry mass by an increase in cell size or
number.
Growth
__________________________________________________________________
e) Removing toxic waste material produced by chemical reactions in the
organism.
Excretion
______________________________________________________________
Respiration
Sensitivity
nutrition
Excretion
Growth/reproduction