Biology
Mrs. Kempf
Vocabulary for Chapter 4
4-1
Weather – the day-to-day condition of the Earth’s atmosphere at a particular time and
place
Climate – the average, year-after-year conditions of temperature (how hot or cold) and
precipitation (how dry or moist) in a particular region
Greenhouse gases – Carbon dioxide (CO2), water vapor, methane, and several other
gases in our atmosphere
Greenhouse effect – Greenhouse gases in our atmosphere allow some sunlight to reach
the Earth but trap the infrared heat that is radiated back, so our Earth stays warm enough
during the night and winter, and cool enough during the day and summer to support life
Polar zone – indirect sunlight all year long (sun’s rays hit this area around the north and
south poles at a very low angle) so less heating, so cold most of the year. Dry
Temperate zone (or mid-latitudes)– angle of sun varies due to tilt of the Earth, which
cause seasons, so hot summers and cold winters. Moisture varies
Tropical zone (or tropics) – direct sunlight all year long (sun’s rays hit the area around
the equator at a high angle, close to 90 degrees), so more heating, so warm or hot most of
the year. Lots of precipitation (very moist)
Surface ocean currents – warm in the tropics, cool in the polar region. Caused by winds
Deep (subsurface) ocean currents – cold water sinks and flows towards equator where
it warms and rises. Transports heat in the biosphere
Oceans cause air masses over them to be moister than air over land.
Landmasses cause air masses over them to be drier than air over oceans.
Air at higher elevations (higher altitude, farther away from earth) is cooler.
4-2
Biotic factors – the biological influences on organisms with an ecosystem
Abiotic factors – Physical, or nonliving factors that shape ecosystem
Survival, growth, and productivity of an organism are determined by biotic and abiotic
factors.
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Biology
Mrs. Kempf
Habitat – the area where an organism lives, including both biotic and abiotic factors (like
its address)
Niche – the full range of physical and biological conditions in which an organism lives
and the way in which the organism uses those conditions (like its job)
Community Interactions – competition, predation, symbiosis can powerfully affect an
ecosystem
Resource – any necessity of life, such as water, nutrients, light, food, or space
Competitive Exclusion Principle – no two species can occupy the same niche in the
same habitat at the same time.
Predation – an interaction in which one organism captures and feeds on another
organism
Symbiosis – any relationship in which two species live closely together
Mutualism – A type of symbiosis where both species benefit. Ex., flowers and insects
Commensalism – a type of symbiosis where one member of the association benefits and
the other is neither helped nor harmed. Ex., barnacles
Parasitism – A type of symbiosis where one organism lives on or inside another
organism and harms it. Ex., tapeworms
Ecosystems are constantly changing in response to natural and human disturbances. As
an ecosystem changes, older inhabitants gradually die out and new organisms move in,
causing further changes in the community.
Ecological succession – Series of predictable changes that occur in a community over
time.
Primary succession – Succession that occurs on surfaces where no soil exists. Ex. After
volcanic eruptions
Pioneer species – the first species to populate the area in the process of primary
succession. Ex., lichens
Secondary succession – when a disturbance of some kind changes an existing
community without removing the soil. Ex., when land is cleared by farming or fire
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Biology
Mrs. Kempf
4-3
Biome – a complex of terrestrial communities that covers a large area and is
characterized by certain soil and climate conditions and particular assemblages of plants
and animals
Tolerance – the ability to survive and reproduce under conditions that differ from their
optimal conditions
Microclimate – The climate in a small area that differs from the climate around it. Ex.
mountains and urban areas
The world’s major biomes include tropical rain forest, tropical dry forest, tropical
savanna, desert, temperate grassland, temperate woodland and shrubland, temperate
forest, northwestern coniferous forest, boreal forest, and tundra. Each of these biomes is
defined by a unique set of abiotic factors – particulary climate – and a characteristic
assemblage of plants and animals.
Other land areas that do not fall neatly into the major biome categories are mountain
ranges and polar ice caps.
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Aquatic ecosystems are defined primarily by the depth, flow, temperature, and chemistry
of the overlying water.
Freshwater ecosystems can be divided into two main types: flowing water ecosystems
and standing water ecosystems.
Plankton – a general term for the tiny, free-floating or weakly swimming organisms that
live in both freshwater and saltwater environments.
Phytoplankton – single-celled algae that are supported by nutrients in the water and
form the base of many aquatic food webs.
Zooplankton – planktonic animals that feed on the phytoplankton
Wetland – an ecosystem in which water either covers the soil or is present at or near the
surface of the soil for at least part of the year.
Estuaries – wetlands formed where rivers meet the sea. They contain a mixture of fresh
water and salt water and are affected by the rise and fall of ocean tides.
Detritus – made up of tiny pieces of organic material that provide food for organisms at
the base of the estuary’s food web.
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Biology
Mrs. Kempf
Salt marshes – temperate zone estuaries dominated by salt-tolerant grasses above the
low-tide line, and by seagrasses under water.
Mangrove swamps – coastal wetlands that are widespread across tropical regions,
including southern Florida and Hawaii. The dominant plants are several species of salttolerant trees, collectively known as mangroves.
Photic zone – photosynthesis is limited to this well-lit upper layer of marine ecosystems
(oceans)
Aphotic zone – permanently dark zone below the photic zone. Chemosynthetic
autotrophs are th only producers that can survive in the aphotic zone.
In addition to the division between the photic and aphotic zones, marine biologists divide
the ocean into zones based on the depth and distance from shore: the intertidal zone, the
coastal ocean, and the deep ocean.
Zonation – is the prominent horizontal banding of organisms that live in a particular
habitat.
Coastal ocean – extends from the low-tide mark to the outer edge of the continental
shelf, which is the relatively shallow border that surrounds the continents.
Kelp forests – one of the most productive coastal ocean communities. Comprised of
giant brown alga that can grown as much as 50 centimeters per day.
Coral reefs – the warm, shallow water of tropical coastal oceans, among the most diverse
and productive environments on earth. Made of hard, calcium carbonate from the
skeletons of coral animals.
Open oceans – or oceanic zone, begins at the edge of the continental shelf and extends
outward. The largest marine zone. Characterized by high pressure, frigid temperatures,
and total darkness.
Benthic zone – The ocean floor that contains organisms that live attached to or near the
bottom, such as sea stars, anemones, and marine worms.
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