Download Interactions Chapter 4

Interactions
Ecology
• Study of organisms and how they interact with
each other and the environment
• Abiotic
Biotic
Limiting Factors
• Can be abiotic or biotic, have significant
impact on organisms’ ability to survive
Examples of Limiting Factors
A. Snakes and lizards live where it is warmer
B. Monarch butterflies require milkweed plants
as food source for caterpillars
C. Fish and amount of DO in water-trout need
more than bass, which need more than
catfish
D. Plants and availability of sunlight or nutrients
in soil
Hierarchy of Organization
• Atoms  Molecules  Organelles  Cells 
Tissue  Organs  Organ Systems 
*Organism  Populations  Communities 
Ecosystems  Biosphere
• What is the biosphere?
Habitat vs. Niche
• Habitat-
• Niche-
Competitive Exclusion Principle
• No two species can occupy the same niche. If
they do, competition between the two will be
intense and one species will outcompete the
other
• This can lead to:
Natural Selection and Evolution
• “survival of the fittest”
• More successful organisms survive and
produce more offspring
4 Premises for Evolution
1. More offspring are produced than can
survive (ex. Rabbits, apple seeds)
2. Resources are limited (as population
increases, resources decrease)
3. Within a population, there is variation (DNA)
4. Organisms that adapt better or have better
traits are ones that survive and reproduce
(populations are smallest unit that can
evolve)
Example of Natural Selection
• Industrial Revolution in England
• Peppered Moths (2 Forms- Light and Dark)
Organism Interactions
Relationship
Species 1
1. Predation
Predator +
2. Competition
3. Parasitism
Parisite +
4. Commensal+
ism
5. Mutualism
+
Species 2
Prey Host –
o
+
2 Types of Competition
• Intraspecific
• Interspecific
* Winner is better adapted and thus more likely
to pass genes on to next generation
Roles of Organisms in Ecosystems
1. Producers- convert inorganic molecules into
organic molecules through ___________
Ex. Plants, ferns, mosses, algae
Roles of Organisms in Ecosystems
2. Consumers- consume organic matter for
energy and organic molecules necessary to
grow
Types of Consumers
A.
B.
C.
D.
E.
Herbivore
Carnivore
Omnivore
Scavenger
Parasite
Roles of Organisms in Ecosystems
3. Decomposer- returns organic molecules into
inorganic material; completes the recycling of
atoms
Ex. Fungi, bacteria, some insects and worms
Energy Flow Through Ecosystems
• All energy for life on Earth comes from the ___
Trophic Levels
• Less individuals each time you move up a
trophic level. Why?