Download Interactions of Living Things Power Point

Interactions of
Living Things
7th Grade Science
PART 1
2
Biotic vs. Abiotic
-Biotic – all LIVING parts of environment.
-ex: tree, fly, people
-Abiotic – all NONLIVING parts of environment.
-ex: water, soil, sunlight, temp.
3
Levels of Environmental Organization
1.
2.
3.
4.
5.
Organism
Population – all same species that live in area
Community – all species that live in area
Ecosystem – community plus abiotic factors
Biosphere – all ecosystems, anywhere life
exists
4
5
Salt Marsh – page 6
-What are some biotic factors in this marsh?
*cordgrass
*jellyfish
*egret
*heron
*algae
*marsh crab
-What are some abiotic factors?
*water
*sunlight
*soil
*temperature
6
PART 2
LIVING THINGS NEED ENERGY
7
Players in the Energy Game
-Producers – use sunlight to make food
-ex: plants, algae
-Consumers – eat other organisms
-herbivore – eats only plants
-omnivore – eats both plants & animals
-carnivore – eats only animals
-scavenger – eats dead plants & animals
8
-Decomposers – get energy by breaking down
dead organisms
-ex: bacteria & fungi
-called nature’s recyclers
9
Food Chains
-Diagram that
shows energy
flow from one
organism to
another
-Why are these
rare in nature?
10
Food Webs
-More realistic than chains
-Interconnected chains show feeding
relationships in ecosystem
-Arrows – is eaten by
11
12
Energy Pyramids
-diagram that shows loss of energy as it passes
through food chains
Amount of
energy
decreases
as you
move up
the levels
Amount of
toxins
increase
as you
move up
the levels
13
PART 3
TYPES OF INTERACTIONS
14
Limiting Factors
-Scarce resource that limits size population can
grow
-ex: food becomes a limiting factor when
population outgrows amount of food
available
15
Carrying Capacity
-Largest population an environment can support
at any given time
-When a population grows larger than carrying
capacity, limiting factors cause individuals to die
or leave
16
Competition
-2 or more individuals or
populations trying to use
the same resource.
17
Predators vs. Prey
-Predator – organism that eats the prey
-wide variety of methods & abilities for
getting food
A cheetah’s speed gives it an
advantage over other predators
competing for the same prey
18
Prey Adaptations
-Prey have methods to keep from being eaten:
1. stay in groups
2. camouflage
3. defense (poison, chemical, physical)
4. burrowing
19
Stay in groups or Herds
20
Camouflage
21
Defense
22
Warning Coloration
23
Symbiosis
-Close, long-term association between
members of 2 or more species
-classified as one of the following:
1. mutualism
2. commensalism
3. parasitism
24
Mutualism
-Both organisms benefit from the interaction.
-ex: you & e.coli in your stomach!!!
25
Commensalism
-One organism benefits, the other is
unaffected.
-ex: sharks & remoras
26
Parasitism
-One organism benefits, the other is harmed.
-organism that benefits - parasite
-organism harmed - host
-ex:
Caterpillar &
Wasp eggs
27