Download Section 2.1 Summary – pages 35

Sharing the World
• What affects the
environment also
affects you.
• Understanding
what affects the
environment is
important because
it is where you live.
What is ecology?
• The branch of biology that
developed from natural history is
called ecology.
• Ecology is the study of interactions
that take place between organisms
and their environment.
The nonliving environment: Abiotic
factors
• The nonliving parts of an organism’s
environment are the abiotic factors.
• Examples of abiotic factors include air
currents, temperature, moisture, light, and
soil.
The nonliving environment: Abiotic
factors
Food production
(mg of glucose/hr)
• This graph shows how the plant’s glucose
(food) production is affected by temperature.
Food Production in Salt Bush
15
10
5
10
20
30
Temperature (°C)
40
50
The living environment: Biotic factors
• A key consideration of ecology is that living
organisms affect other living organisms.
• All the living organisms that inhabit an
environment are called biotic factors.
• All organisms depend on others directly or
indirectly for food, shelter, reproduction or
protection.
Organism
• An individual living thing that is made of cells,
uses energy, reproduces, responds, grows,
and develops.
• A population is a group of organisms, all of the
same species, which interbreed and live in the
same area at the same time.
• A biological community is made up of
interacting populations in a certain area at a
certain time.
Ecosystem
• Populations of plants and animals that interact with each other in
a given area and with the abiotic components of that area.
The Biosphere
• The biosphere is the
portion of Earth that
supports living
things.
• It extends from high
in the atmosphere to
the bottom of the
oceans.
Biotic and abiotic factors form
ecosystems
Table 2.1 Examples of Ecosystems
Aquatic
Other Sites for
Terrestrial
Ecosystems
Ecosystems
Ecosystems
Human body
Freshwater
• Forest
• Skin
• Old farm field • Pond
• Intestine
• Lake
• Meadow
• Mouth
•
Stream
• Yard
Buildings
• Estuary
• Mold in walls,
• Garden plot
floors, or basement
Salt water
• Empty lot
(marine)
• Ventilation systems
• Compost heap • Ocean
•Bathrooms
Food
• Estuary
• Volcano site
• Any moldy food
• Aquarium
• Rotting log
• Refrigerator
• Terrestial
ecosystems
are those
located on
land.
•Aquatic
ecosystems
occur in both
fresh- and
saltwater forms.
Organisms in Ecosystems
• A habitat
is the
place
where an
organism
lives out
its life.
Organisms in Ecosystems
• Habitats can change, and even disappear.
Habitats can change due to both natural and
human causes.
Niche
• Although several species may share a habitat,
the food, shelter, and other essential
resources of that habitat are often used in
different ways.
• A niche is the role or position a
species has in its environment—
how it meets its specific needs for
food and shelter, how and where it
survives, and where it reproduces in
its environment.
Niche
• A species’ niche, therefore, includes all its
interactions with the biotic and abiotic parts of
its habitat.
• It is thought that two species can’t exist for
long in the same community if their niches are
the same.
HABITAT
OR
NICHE ???
P. means Parmecium which is
a one-celled protist that lives
in ponds and other
freshwater bodies of water.
Graphs showing competition between two species of Paramecium. Since
each population alone prospers (FIRST two graphs), when they are in a
competition situation one species will win, the other will lose (THIS graph).
Images from Purves et al., Life: The Science of Biology, 4th Edition, by
Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission..
•It is thought that two
species can’t exist for
long in the same
community if their niches
are the same. One will
compete better than the
other and survive.
Symbiosis
• The relationship in which there is a
close and permanent association
between organisms of different
species is called symbiosis.
• Symbiosis means living together. Three kinds
of symbiosis are recognized: mutualism,
commensalism, and parasitism.
• A symbiotic
relationship
in which both
species
benefit is
called
mutualism.
• Commensalism is
a symbiotic
relationship in
which one
species benefits
and the other
species is neither
harmed nor
benefited.
Parasitism
• Some interactions are harmful to one species,
yet beneficial to another.
• A symbiotic relationship in which a
member of one species derives
benefit at the expense of another
species (the host) is called
parasitism.
Parasitism
• Parasites have evolved in such a way that
they harm, but usually do not kill the host
species.
Are these two playing? If not, then
what type relationship is this ??? Is it
a relationship???