• What is the difference between weather
three main zones are the polar, tropical, and
climate: the far northern and southern
regions of Earth
zone: surrounds the equator
zone: the wide area in between
the polar and tropical zones
The Greenhouse Effect
• Greenhouse gasses such
as carbon dioxide trap
heat in the Earth’s
4.2 Niches and Community
Organism has a habitat and
habitat is the general place in
which an organism lives.
niche describes not only the
place an organisms lives, but the
range of physical and biological
conditions in which it lives and
The Competitive Exclusion
• If two species attempt to
occupy the same niche, one
species will be better suited
to obtain limited resources
and will eventually exclude
What would happen if two of these warbler species tried to occupy the same niche
at the same time?
or more species living together
in a close, long-term association.
– the host is harmed
and the parasite benefits
eventually die as
its organs are
by wasp larvae.
Organism is harmed
larvae feed on
their host and
– benefits both
Clownfish and sea anemone
– one species
benefits, and the other is neither
harmed nor helped
Barnacles on a blue whale
new land is created, or a habitat is
destroyed by disaster a new habitat will be
is a regular progression of species
succession occurs where life has not
A new volcanic island
succession occurs where there has been
A forest that has been burned
are described in terms of abiotic and biotic
biomes produce lush
abundant precipitation all year
Source: World Meteorological Organization
biomes are where the primary
plant life is grass.
grasslands are dry and warm
during the summer; most precipitation
falls as snow.
Tropical grasslands (savanna) are warm through the
year, with definite dry and rainy seasons.
biomes are characterized by a very
very low amount of precipitation
four types: hot, semi-arid, coastal, and cold
forest biomes include
deciduous forests and rain forests.
Temperate deciduous forests have hot summers and cold winters.
Deciduous trees are the dominant plant species.
taiga biome is located in cooler
long winters and short summers
small amount of precipitation
tundra biome is found in the far
northern latitudes with long winters.
winter lasts 10 months
4.5 Aquatic Ecosystems
• Nearly ¾ of Earth’s surface is covered
• Aquatic organisms are affected
primarily by water depth, temperature,
flow, and amount of dissolved
• Freshwater ecosystems include moving
and standing water (wetlands, lakes and
ponds, and rivers and streams).
are dynamic environments
where rivers flow into the ocean.
of fresh water with salt water
as spawning and nursery grounds
for many fish and shellfish
Estuaries are highly productive ecosystems.
provide a protected refuge for many
are primarily threatened by land
Affected by tides
Coral reefs and kelp forests
90% of ocean
Photic and Aphotic zones