INTERACTION OF LIVING
THINGS AND CYCLES IN
NATURE.
Chapter 2 and 3 review
Two main part of an environment


Biotic Factors: all the living organisms that live and
interact with one another.
Abiotic Factors: all the non-living elements of an
environment.
Biotic factors
Abiotic Factors
The five levels of environmental
organization.





Organism: one organism of one species.
Population: two or more organisms of the same
species.
Community: different populations of organisms
living together.
Ecosystem: a community of organisms and the
abiotic factors.
Biosphere: the part of Earth where life exists
Arrange the following pictures in the
correct sequence.





A._____________
B._____________
C._____________
D._____________
E._____________
Three
One
Four
Two
Five
Links in a food chain

A food chain shows the pathway of energy transfer
as a result of how organisms’ eating patterns.
Sun

The ultimate source of energy for all living things.
Consumers



Consumers can be level one (primary) or level two
(secondary) consumers.
Level one consumers can be herbivores which mean
they only eat plants, or omnivores which means they
plants and animals.
Level two consumers can be omnivores or carnivores
which eat only meat.
Level one consumers
Level two consumers
Scavanger

Scavengers are consumers that eat the left overs of
other consumers.
Decomposers

Decomposers break down dead organisms and
return nutrients to the soil.
Food Web

A food web shows the feeding relationships
between lots of different organisms in an
ecosystem.
Can you answer these questions?
1. Name the living things in the food web that
are producers. ______________________
______________________________________
______________________________________
2. Name the living things in the food web that
are consumers. ____________________
______________________________________
______________________________________
3. Which living things does the snake eat?
______________________________________
4. Which living things does the hawk eat?
______________________________________
5. What is eaten by the rabbit?
______________________________________
6.What is the owl classified as?
______________________________________
Energy Pyramid



An energy pyramid shows an ecosystems loss of
energy as it passes from one organism to the next.
An ecosystem must have more producers than
consumers or it will collapse.
An ecosystem must have more level one consumers
than level two consumers are it will collapse.
What does an energy pyramid look
like?
Limiting Factors
The growth of a population is controlled by limiting
factors.
Limiting factors are resources that are necessary for
life.
Limiting factors are food, water, space. Amount of
sunlight, temperature and other natural resources.
Carrying capacity and competition

Carrying capacity is the largest population an
ecosystem can support. Limiting factors control the
carrying capacity of all ecosystems.
Competition

Competition is when two or more individuals or
populations complete for the limiting factors that
are available in a particular ecosystem.
Predators

Predators are organisms that all or part of another
organism. Predators are hunters.
Prey

Prey are organisms that are killed and eaten by
other organisms.
What are adaptations?
Adaptations allow predators to catch their prey, but
also allow prey to escape predators.
 Some adaptations are:
Camouflage; speed; staying in herds; defense
chemicals; quills; talons.

Mutualism

Mutualism is a symbiotic relationship in which both
organisms benefit.
Commensalism

Commensalism is a relationship where one organism
benefits and the other is not affected.
Parasitism

Parasitism is a relationship in which one organism
benefits and other is harmed.
Water cycle
The water cycle is the movement of water between
oceans, atmosphere, land and living things.
 The main parts are:
Evaporation
Condensation
Precipitation
Run-off

Water Cycle
Carbon Cycle


The carbon cycle is the exchange of carbon
between the environment and living things.
Photosynthesis is the basis of the carbon cycle.
Nitrogen Cycle

The nitrogen cycle is the movement of nitrogen
between the environment and living things.