Transcript GHSGE Review

AHSGE Review
J. Pollock
Spring 2007
Ecology
Describe levels of organization
in the biosphere.
 The ecosystem is all living and nonliving things
in the environment.
 Within the ecosystem, there are food webs
(interrelated chains of organisms that depend on
each other for food).
 The aspects of an animal’s lifestyle are referred
to as niche.
 The habitat is the physical surroundings in which
an organism lives.
Describe levels of organization
in the biosphere.
 The biosphere is the part of the earth where
life exists. It is composed of air, land, and
water.
 Large regions that are identifiable by the
types of plants and animals living there are
biomes.
How does energy flow through the
trophic levels of the ecosystem?
 Food webs are interrelated cahins of organisms
that depend on each other for food.
 Producers are the green plants that make their
own food.
 Consumers are the animals that rely on other
organisms for food.
 Scavengers feed on dead organisms.
 Decomposers are organisms that break down
dead organic matter.
Consumers
 Consumers can be primary, secondary, or tertiary.
 Primary consumers are herbivores, or plants
eaters.
 Secondary consumers are carnivores, or flesh
eaters.
 Tertiary consumers are omnivores, which eat
both plants and animals.
 With each increasing level of the food web,
energy is lost when it is consumed.
Food Web
What are biotic factors?
 Biotic factors are living things.
 Plants
 Animals
 Parasitism
 Disease
 predation
What are abiotic factors?
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Abiotic factors are nonliving things.
Light intensity
Temperature range
Type of soil or rock
pH level
Water availability
Dissolved gases
Level of pollutant
Compare autotrophs and
heterotrophs.
 Autotrophs
 Heterotrophs
– Obtains energy from
– Cannot make own
sunlight or chemicals
– Undergo
photosynthesis
food
– Undergo cellular
respiration
What is the niche of
decomposers?
 Decomposers break down dead organic
matter.
 They produce the raw materials used for
photosynthesis.
 They prevent the buildup of dead matter
and insure that nutrients are available for
producers.
What is the ten percent law, and how does it
relate to energy flow through tropic levels?
 Only a small amount of energy is available
for transfer from one trophic level to the
next.
 Most of the energy is lost to the
surroundings as waste heat.
 According to the ten percent law, only
about 10% of the energy in a trophic level
is transferred to the next trophic level.
What are biomes?
 Biomes are regions of the earth that are
identified by the types of plants and
animals that live there.
 There are 8 biomes.
What are the biomes of Earth
and their characteristics?
BIOME
REGIONS
FLORA
FAUNA
CHARACTERISTICS
Polar
North and south
poles
Moss and lichen
Polar bears, penguins
Permafrost
Tundra
Arctic/Antarctic
regions
Grass and
wildflowers
Reindeer, caribou
Thin soil, permafrost
Taiga
Northern forests
Stunted conifers
Wolves, rabbits
Long,cold winters
Deciduous forest
NE/mid-eastern US,
W. Europe
Deciduous trees
Deer, birds, small
animals
Mod. Precipitation,
warm summers, cold
winters
Grasslands
Mid-western US,
Eurasia, Africa
Grasses
Prairie dogs, ferrets,
snakes
Hot summers, cold
winters, rainfall
unpredictable
Desert
W. US, N. and SW
Africa
Cacti, succulents
Jackrabbits, lizards,
rats
Arid, extreme daily
temperatures
Tropical rainforest
South America
Diverse plants
Monkeys, leopards
High rainfall and
temperatures
Temperate rainforest
NW US
Giant conifers
Bear, deer, birds
Moist soil, high
rainfall, moderate
temperatures
What are limiting factors in an
ecosystem?
 A limiting factor is one that controls a
process, such as organism growth or
species population size or distribution.
 They can biotic or abiotic.
 Food
 Shelter
 Water
 predation
What is the water cycle?
 The water cycle is Earth’s system of recycling
water.
 About 70% of Earth’s surface is covered with
water.
 In the water cycle, water evaporates from oceans,
lakes, and rivers and rises into the atmosphere.
The water condenses to form droplets in clouds.
The droplets become heavy, and water falls back
to Earth as precipitation. Runoff collects back
into oceans, lakes, and rivers, and the process is
repeated.
Water Cycle
What is the carbon cycle?
 The carbon cycle is a model that describes
how carbon molecules move between the
living and nonliving world.
 Producers remove carbon dioxide from the air
during photosynthesis. They use
photosynthesis to produce energy-rich
molecules. This energy is released during
cellular respiration. Cellular respiration
releases carbon dioxide.
Carbon Cycle
What is the oxygen cycle?
 The oxygen cycle describes the movement
of oxygen within the atmosphere, the
biosphere, and the lithosphere.
 It is driven by photosynthesis.
 It works closely with the carbon cycle.
Oxygen Cycle
What is the nitrogen cycle?
 The nitrogen cycle is a model describing how
nitrogen moves from the atmosphere to the soil,
to living organisms, and then back to the
atmosphere.
 Nitrogen is essential to creation of proteins,
which are required by the cells of all organisms.
 Plants and animals cannot directly absorb
nitrogen from the soil or atmosphere, so nitrogenfixing bacteria are necessary for the process.
Nitrogen Cycle
What events affect the
equilibrium of ecosystems?
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Weather
Global warming
Introduction of non-native species
Strip mining
Agriculture
Burning fossil fuels
Acid rain
Ozone depletion
Construction
Waste disposal
How do humans affect the
equilibrium of ecosystems?
 Humans consume large amounts of natural
resources, destroying much of the environment
and natural habitats.
 We also produce ever-increasing amounts of
waste.
 We mine fossil fuels and minerals, damaging the
environment in the process.
 The greenhouse effect is being magnified by our
use of fossil fuels and acid rain is being created.
What is ecological succession?
 Ecological succession is the change in
dominant species in an area.
 A pioneer community is a plant species that
colonizes an area. It is a hardy species, and it
makes the habitat hospitable for other
organisms.
 Different species become dominant until a
climax community is reached.
 A climax community is the final stage of
ecological succession. There are many types of
plants, and it is very stable. It changes little.