1. Interactions of Living Things
Chapter 12
Interactions of Living Things

2. Section 1 : Everything Is Connected
Studying the Web of Life
Ecology – the study of the interactions between organisms and their environment
The environment consists of two parts:
1) Biotic – is the part of the environment where all organisms live and interact with one another
2) Abiotic – is the part of the environment that includes physical factors like; water, soil, light, and temperature, which affects how an organism lives

3. Organization in the Environment
The environment can be arranged into the following 5 levels (smallest to biggest):
1) Organism
2) Population
Population – a group of organisms of the same species living in the same area
3) Community
Community – all the populations of different species that live in a certain area
4) Ecosystem
Ecosystem –is the community of organisms and their non living environment (abiotic)
5) Biosphere
Biosphere – the part of the Earth where life exists.
It extends from the deepest parts of the ocean to the upper atmosphere

4. Chapter Quiz 1
1) _____________ is the the study of the interactions between organisms and their environment
2) ____________ is the part of the environment where all of the organisms live and interact
3) ___________ is a group of individuals of the same species living in the same area
4) ___________ is the part of the Earth where life exists, from the deepest parts of the ocean to the upper atmosphere
B) ___________ is a organism that only eats plants

5. Section 2 – Living Things Need Energy
The Energy Connection
Organisms can be divided into 3 groups based on how they obtain energy;
PRODUCERS – are organisms that use sunlight directly to make food
this process is called Photosynthesis
Producers include plants, algae, and some bacteria

6. There are several kinds:
2) CONSUMERS – are organisms that eat producers and other organisms to obtain their energy.
There are several kinds:
a) Herbivores – consumers that only eat plants
b) Carnivores – consumers that only eat animals
c) Omnivores – consumers that eat both plants and animals
d) Scavengers – consumers who eat dead animals
3) Decomposers – are organisms that get their energy by breaking down the remains of dead organisms

7. Food Chains & Food Webs
Food Chains – are representations of how energy is transferred from one organism to another
Because an organism rarely eats one type of food, food chains rarely occur in nature
Food Webs – are representations of the many possible energy pathways to organism.
Energy moves from one organism to the next in a one way direction
Any energy not immediately used by the organism is stored in it’s tissues
Only the energy stored in tissues can be used by the next organism

8. Energy Pyramids
Energy Pyramid – represents the loss of energy between each level of the food chain
Energy pyramids have large bases and narrow tops. This represents that the amount of available energy is greater at the bottom and reduced as you go up
Most organisms use the energy they consume and store very little

10. Habitat and Niche
Habitat – is the environment in which an organism lives
Niche – is an organisms way of life within an ecosystem
It includes an organisms habitat, food sources, predators, and its competitors
Abiotic factors (sunlight, soil, etc) are also included in a niche

11. Chapter 12 – Quiz 2
1) ____________ are organisms that use sunlight to make their food.
2) ____________ are organisms that eat other organisms to obtain their energy
3) ___________ are organisms that get their energy by breaking down the remains of dead organisms
4) ___________ is the environment in which an organism lives.
5) ___________ is the way an organism lives in its environment.
B) ___________ is the name of the organism that is eaten by another organism

12. Section 3 – Types of Interactions
Interactions with the Environment
Limiting Factor – is when one or more resource that an organism needs, becomes scare
Resources include; food, water, living space, etc.
Any single resource can become a limiting factor
Carrying Capacity – is the largest population that an environment can support

13. Interactions Among Organisms
Populations contain interacting individuals of the same species, while communities contain interacting populations of several species
Scientists have described 4 ways that species and individuals affect each other
1) Competition – when two or more individuals or populations try to use the same limited resource
Because resources are limited when one individual uses it there is less available for the other individuals

14. Predator Adaptions Prey Adaptations
2) Predator and Prey
Prey – is the organism that gets eaten
Predator - the organism that eats the prey
Predator Adaptions
In order to survive predators must be able to catch their prey
Predators must have adaptions that benefit (speed. Camouflage, poisons, etc)
Prey Adaptations
Prey have adaptations themselves to help keep them from being eaten

15. 3) Symbiosis
Symbiosis – is a close, long-long term association between two or more species
There are three types of symbiotic relationships:
A) Mutualism
Mutualism - is a symbiotic relationship where both organisms benefit
B) Commensalism
Commensalism – is a symbiotic relationship where one organism benefits and other remains unaffected
C) Parasitism
Parasitism – is a symbiotic relationship where one organism benefits and the other is harmed .

16. Coevolution
Coevolution – is a long-term change that takes place in two species because of their close interactions with one another.

17. Chapter 12 Quiz 3
1) ___________ is when one or more resource becomes scarce
2) ___________ is the largest population that an environment can support
3) ___________ is an organism that eats another organism
4) ___________ is a close long-term association between two or more species
5)___________ is a long-term change that takes place between two species because their close interactions with one another
B) (3 points) – List the five levels of environmental organization from smallest to largest