Transcript Unit 11 NOTES - Cobb Learning

Relationships, Biomes &
Population Growth
Unit 11
Relationships
What is Ecology?
Ecology: Scientific study of interactions
among organisms and between organisms
and their environment.
What are the levels of organization?
To understand relationships within the biosphere, ecologists ask
questions about events and organisms that range in complexity from a
single organism to the entire biosphere.
What are the levels of organization?
Species: Group of similar
organisms that can breed and
reproduce fertile offspring.
One
Zebra
What are the levels of organization?
Populations: Group of individuals
of the same species that live in
the same area.
Herd of zebra
What are the levels of organization?
Communities: Assemblage of
different populations that live
together in a defined area.
Herd of
animals on
the Serengeti
What are the levels of organization?
Ecosystem: A biological
community and all of the
abiotic factors that affect it.
What are the levels of organization?
Biome: Group of ecosystems that have the
same climate and similar dominate
communities.
Rainforest
Desert
What are the levels of organization?
Biosphere: Part of Earth in which life
exists including land, water, and air or
atmosphere.
What are ecosystems composed of?
• Ecosystems are influenced by biological and physical factors.
• The biological influences on organisms within an ecosystem are
called biotic factors.
• Includes; all biological creatures which an organism may interact
or, it’s community. Mushrooms, birds, trees, bacteria
What are ecosystems composed of?
• Physical, or non-living factors that shape ecosystems are
called abiotic factors.
• Includes; the climate like—temperature, precipitation,
humidity, wind, nutrient type, soil type, sunlight etc.
What is an ecosystem composed of?
Mountain,
clouds, water &
rocks
Non-Living ONLY
Abiotic Factors
Biotic Factors
Living ONLY
Trees, bird, grass,
rabbit, & moose
ECOSYSTEM
Living & Non-Living
Together
What is a habitat?
Habitat: An area where organisms live
Provides:
* Food
* Water
* Space
* Shelter
What is a niche?
• Is the organisms occupation...Its job...What it does.
• A niche is the full range of physical and biological
conditions in which an organism lives and the way in which
the organism uses those conditions.
What is symbiosis and what are the different types?
• Any relationship in which two species live closely
together is called symbiosis or “living together”
• Examples: mutualism, commensalism, parasitism
What is symbiosis and what are the different types?
Mutualism: Both species benefit.
(Ex.: Bee and flower & Cleaner fish/other fish)
Mutualism Video
What is symbiosis and what are the different types?
Commensalism: One member benefits and the other
is neither helped nor harmed.
(Example: bird nest in a tree, barnacle on a whale)
What is symbiosis and what are the different types?
Parasitism: One organism lives on or inside another
organism and harms it.
• A host is the organism in which a parasite obtains
its nutritional needs.
The cuckoo bird
is a parasite!
Parasite Example
Cuckoo Egg!
The cuckoo lays eggs in
other species of bird’s
nests. It hatches first and
pushes out the other bird’s
eggs. Then the mother bird
raises the cuckoo rather
than her own babies!
Parasite Example
• This is a tapeworm. If
your dog/cat ingests a
flea, and the flea has a
tapeworm egg in it, this
is born in the animals
intestinal tract and feeds
off of the animals food.
What is the difference between weather & climate?
Weather is the day to day
condition of Earth’s atmosphere
at a particular time and place.
Climate refers to the average year
after year conditions of
temperature and precipitation in
a particular region.
What is a climatogram?
A Climatogram is a diagram that summarizes
a region’s climate, including temperature
and precipitation.
The Major Biomes
• The major biomes are defined by a unique set of abiotic factors
• Each has a characteristic ecological community and each is
defined by its climate (temperature & precipitation)
• It has nothing to do with countries!
Types of Biomes
Tropical Rainforest
Hot, wet biome with yearround humidity
Contains Earth’s MOST
diverse species of plants and
animals
Tundra
A biome that is treeless with a layer of permanently
frozen soil below the surface called permafrost
* Very little
precipitation!
Taiga/Boreal Forest
* South of the tundra
* Lacks permafrost layer
* Summers are warmer and
longer than the tundra.
Temperate Grassland
* Mostly grasses and very few trees
* Fertile soil
* Many grazing animals like buffalo & horses
* Also called prairies in the US
Temperate Grasslands
* These grasses contain oils that make them flammable
* Grass fires help the biome’s grasses grow healthier
after the fire
Tropical Savanna
Grasses with scattered trees
Desert
* Annual rate of evaporation exceeds the rate of precipitation
* Very little rain
* Can have a little variety of animals
Populations
What affects a population?
1. Predation
- Predators: as the number of prey increase, the number of
predators will too
2. Disease
-
Outbreaks occurs when population density is high
Disease is transmitted easier
3. Parasites
-
Similar to disease, when population density
is high, parasites are
transmitted easier
4. Competition
- Individuals compete for:
Food, water, shelter, & space
What is Population Growth Rate?
• Population Growth Rate: Explains how fast a given
population grows
– If death rates decrease and births increase, the
population with increase OR decrease?
• Emigration: Used to describe the number of
individuals who move away from a population.
• Immigration: Used to describe the number of
individuals who move into a population.
Types of Growth
Predator/Prey Model:
As the number of lynx increase, the number of hare also increase.
As then number of hare decrease, the number of lynx decrease.
Population Limiting Factors
• Density-dependent
– Deaths occur more quickly in a crowded
population
– Ex: resources, predation, disease
• Density-independent
– A certain proportion dies regardless of
population density
– Ex: severe weather, natural disaster
Types of Growth
Exponential Growth Model:
Bacteria in a Petri dish
• Food is placed into a Petri dish, and bacteria is introduced to the food.
• The first 2 hours is the “lag phase”, followed with exponential growth.
• During the 2nd hour, bacteria begin to reproduce because there is
plenty of food available.
• The bacteria will grow exponentially until there is no more food, and then
they will all die.
Often referred to as
“J-Shaped Growth”
Lag Phase
Exponential
Growth
Video
Rate of Reproduction Video
Types of Growth
Logistic Growth Model:
• Notice the S-shape in this graph…
the population levels off (stabilizes)
• Carrying Capacity: The maximum number of
individuals in a species that an environment can
support for a long period of time.
Carrying Capacity Video
The End