Download Biology Review Ecology 5.1

Biology Review
Ecology 5.1 & G.1
Kelsey Doucette
First, the easy stuff…..
Define it!!
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Species- a group of organisms that can interbreed and produce fertile
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offspring
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Habitat- the environment in which a species normally lives or the location of
a living organism.
Population- a group of organisms of the same species which live in the
same area at the same time.
Community- a group of populations living and interacting with each other in
an area.
Ecosystem- a community and its abiotic environment.
Autotroph- an organism capable of making their own organic molecules as a
food source.
Heterotroph- an organism that cannot make their own food from inorganic
matter
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Consumer- an organism that feeds on trophic levels below them.
Detritivores- organisms that eat non-living organic matter.
Saprotrophs- organisms that live in or on non-living organic matter,
secreting digestive enzymes into it and absorbing the products of its
digestion.
Trophic Level- an organism’s position in a food chain.
Dung beetles are detritivores.
Fungi are saprotrophs.
Food Chain vs. Food Web
A food chain looks something like this..
algae mosquito larvae dragonfly
larvae fish raccoon
whereas a food web looks like this..
So…which trophic level??
So, to tie up the loose ends..
• Light is the initial energy source for almost all
communities.
• The energy in a food chain travels from the lower trophic
level to the higher trophic level.
• Once light energy has been absorbed by producers, the
chemical energy obtained by photosynthesis is available
to the next trophic level. Energy is transferred from one
organism to the next when carbohydrates, lipids or
proteins are digested. The chemical energy obtained is
then used for cellular respiration.
• Energy transformations are never 100% efficient....but
why???
There are many reasons why not all of the energy
present in an organism can be used by the
organism in the next trophic level:
-Not all of the organism is swallowed as a food source.
-Not all the food swallowed can be absorbed (bones and
hair).
-Some organisms die before being eaten.
-Heat loss is immense due to cellular respiration.
• This is why in pyramids of energy, each level is always
smaller than the one before.
• In an ecosystem most energy is lost as heat and the
term ‘lost’ means that organisms cannot recycle heat
energy.
• However, decomposers in an ecosystem recycle
nutrients. The organisms that carry out the recycling of
these nutrients are saprotrophic bacteria and fungi.
And now, the Option G stuff…
• Factors that affect the distribution of plant species:
-Temperature: adaptations such as leaves that curl to resist
heat.
-Water: adaptations such as long roots to find water.
-Light: adaptations such as larger leaves in shady areas or
smaller leaves in high sun areas.
-Soil pH: plants are either acid-loving, basic-loving or
neutral-loving.
-Salinity: plants either withstand salt or not.
-Mineral Nutrients: mature dunes inland have thick layers of
nutrients while foredunes only contain a small amount of
nutrients.
• Factors that affect the distribution of animal species:
-Temperature: adaptations to high heat such as burrowing
in cool sand.
-Water: some animals depend on wetlands for their eggs
and as a food source.
-Breeding Sites: certain habitats that are protected from the
sun and the wind are necessary for certain animals to
breed.
-Food Supply: many animals are adapted to feed on
specific food and must live where that food supply is
available.
-Territory- animals must separate their territories so that
they do not overlap and affect each other.
Now, how to compare populations??
• In order to compare two populations, you must use a
method of random sampling.
• One way to do so is with the quadrat method. Can
anyone explain?
• Another way to do so is with the transect method. How
about explaining this one? (Remember this deals with
abiotic variables)
An organism’s role in the play of
life…
The Niche concept!!
• This says that every organism has a particular role in
that ecosystem.
• The area inhabited by any particular organism is its
spatial habitat.
• The feeding activities of an organism affect the
ecosystem by keeping other populations in check.
• The interactions of an organism with other species living
in its ecosystem include competition, herbivory,
predation, parsitism and mutualism.
• When a primary consumer feeds on a producer is known
as herbivory.
• When a consumer eats another consumer is known as
predation.
• When two species rely on the same limited resource is
known as competition.
• When two species living together benefit from the
relationship is known as mutualism.
• When an organism lives in or on a host is known as
parasitism.
Name that interaction!
1. Clownfish and sea anemones.
2. Rabbits eating marram grass.
3. Coyotes and red foxes both being predators to small
rodents and birds.
4. Leeches on humans.
5. The blue heron eating frogs.
6. Monarch butterfly larvae eat leaves of the milkweed
plant.
7. Fungi and algae.
8. The Canadian lynx eating arctic hares.
9. The natterjack toad and the common toad live in the
same habitat.
10. Plasmodium on humans.
G.F. Gause said whhhatt??
• No two species in a community can occupy the same
niche according to the principle of competitive exclusion.
• G.F. Gause’s experiment with two species of
Paramecium exemplified this principle. It showed that
when the two species, who are closely related, were
cultured together one species out competed the other.
So what do you call a niche with
and without competition?
• Fundamental: the potential mode of
existence, given the adaptations of the
species.
• Realized: the actual mode of existence,
which results from its adaptations and
competition with other species.
So how do you measure mass of
living plants and animals in an
ecosystem?
• The total mass of organic matter is the
biomass of an ecosystem.
• The method to do so is….? You tell me!