Download Notes - Organisms and their relationships revision

Unit 5 - Ecology
Relationships and Environmental
Factors
Overview
• Every living organism
depends on nonliving
factors found in its
environment and on other
organisms living in the
same environment for
survival.
• Ecology is the study of
relationships among living
organisms and the
interaction the organisms
have with their environment
• Biosphere – the portion of
Earth that supports life (bio
means life, sphere is
something round)
Abiotic vs. Biotic Factors
• Biotic factors – the living
factors in an organisms
environment
– Ex – plants, animals,
bacteria
• Abiotic factors – nonliving
factors in an organisms
environment
– Example – temperature,
air, water, light, soil, pH
• Organisms are adapted to
surviving in their particular
natural environment; if they
move to another location
with different biotic or
abiotic factors, they might
die if they cannot adjust
quickly
Quick Check for Understanding
• As a class, make a list of at least 5 biotic,
and 5 abiotic factors in your environment
that are necessary for your survival
Examples
Levels of Organization
•
•
To study relationships within the
biosphere, ecologists have organized it
into smaller pieces.
The levels are:
1. Organism (a single individual –
one fish, for example)
2. Population (when organisms of a
single species share the same
geographic location at the same
time)
3. Biological community (a group
of populations that interact and
occupy the same space at the
same time)
4. Ecosystem (a biological
community plus all of the abiotic
factors that affect it)
ex – trees plus water and soil
1. Biome (a large group of
ecosystems that share the same
climate and have similar
communities)
Ex – marine or desert biomes
1. biosphere (all the biomes on
Earth combined)
Check for understanding
• Choose an organism – any organism you
are interested in
• Describe the levels of organization of that
organism
• Share your answer with your partner –
random people will be chosen to share
their answer
Limiting Factors
•
Limiting factors – any biotic or
abiotic factor that restricts the
numbers, reproduction, or
distribution of organisms
– Ex – abiotic factors include
sunlight (for plants), climate,
water, nutrients, and space; biotic
factors would include other plants
and animals
•
When a resource like food, water,
or living space becomes scarce,
that factor is what controls the size
of a population.
– example: snakes feed on mice.
The mice eat grain crops. When
the grain crops are plentiful, the
snake population will increase.
When the crops have a bad year
and dry up, there are fewer mice,
and therefore fewer snakes.
Carrying capacity…
• The largest population
that the environment can
support over a long
period of time.
• When a population grows
larger than its carrying
capacity, the limiting
factors in the environment
cause the population to
shrink
Quick Check for Understanding
• As a class, list some abiotic factors that
limit plant growth (think about your
gardens)
• As a class, list some biotic factors that limit
plant growth
• Discuss: how is water a liming factor in
certain ecosystems?
Ecosystem Interactions
• The interactions between
organisms are important in an
ecosystem (remember, an
ecosystem is a group of
organisms interacting and
living together and the abiotic
factors in their environment)
• Habitats – an area where an
organism lives
• Niche – the role or position
that an organism has in its
environment (how it gets its
food, shelter, and reproduces)
Quick Check for Understanding
• Give 2 examples of a habitat, and an
organisms niche within that habitat
• Share your answer with your neighbor
• Random answers will be selected to share
with the class
Community Interactions
•
•
•
•
Organisms that live together in a
community constantly interact – these
interactions (and the abiotic factors)
shape an ecosystem
Interactions include competition for
basic needs like food, shelter, and
reproduction
Competition – occurs when more
than one organism uses a resource at
the same time
– Ex – during a drought, water will
be scarce for many organisms.
The strong organisms compete
with the weak for survival; some
may die, some may move to
another location. If water is
plentiful, competition won’t be as
fierce. Plants compete for
sunlight, animals compete for food
or the chance to mate or a place
to live
Predation – when one organisms eats
another organism (the predator eats
the prey)
– Ex – ladybug eating an aphid
Types of Relationships
•
Symbiotic relationships – a close
relationship between two or more
species
•
There are 3 different kinds:
•
mutualism – when both organisms
benefit from each other
– Ex – hummingbird and flower; one
gets food, the other gets
pollinated
Commensalism – one organism
benefits and the other is neither
helped nor harmed
– Ex – shark and remora fish; sea
anemones and clownfish
Parasitism – one organism benefits
and the other is harmed
– Ex – ticks, fleas, tapeworms,
heartworms
*parasites usually don’t want to kill the
hose, because that’s its home and
source of food – but it will weaken it
and make it very ill (and eventually kill
the host)
•
•
•
Lets Vote
The desert region would be considered
a(n)?
A. Ecosystem
B. Biosphere
C. Biome
D. Organism
Lets Vote
A garden in your backyard would be best
classified as an?
A. Population
B. Ecosystem
C. Biome
D. Biosphere
Lets Vote
Bacteria living in your small intestine help
break down food for nutrient absorption.
This is a perfect example of?
A. Parasitism
B. Mutualism
C. Commensalism
D. Ihavenoideaism
Lets Vote
Contact with human feces (poop) can lead
to a hookworm infection in the small
intestine. If untreated this condition can be
fatal. This is an example of?
A. Competition
B. Mutualism
C. Parasitism
D. Fatalism