Ch.18 Ecology and the Biosphere

Question 1

ecology

Answer 1

The scientific study of the interactions between organisms and their environments.

Question 2

biotic factors

Answer 2

All of the organisms in the area and the living component of the environment.

Question 3

abiotic factors

Answer 3

The environment’s nonliving component and include chemical and physical factors, such as temperature, light, water, minerals and air.

Question 4

habitat

Answer 4

The specific environment an organism lives in and includes the biotic and abiotic factors of its surroundings.

Question 5

Ecology can be divided into 4 increasingly comprehensive levels.

Answer 5

1. Organismal ecology.
2. Population ecology.
3. Community ecology.
4. Ecosystem ecology.

Question 6

Tier I: organismal ecology

an organism is an individual living thing

Answer 6

Concerned with the evolutionary adaptations that enable organisms to meet the challenges posed by their abiotic environments.

Question 7

Tier II: population ecology

Answer 7

Concentrates mainly on factors that affect population density and growth.

Question 8

Tier III: community ecology

Answer 8

Focuses on how interactions between species affect a community’s structure and organisation.

Question 9

Tier IV: ecosystem ecology

Answer 9

Focuses on energy flow ans the cycling of chemicals among the various abiotic and biotic factors.

Question 10

population

Answer 10

A group of individuals of the same species living in a particular geographic area.

Question 11

communities

Answer 11

All the organisms that inhabit a particular area.

Question 12

ecosystems

Answer 12

All the abiotic factors and the community of species in a certain area.

Question 13

biosphere

Answer 13

The global ecosystem - the sum of all the planet’s ecosystems.

Question 14

chemoautotrophic

Answer 14

Bacteria that derive energy from the oxidation of inorganic chemicals (such as hydrogen sulphide in hydrothermal vents).

Question 15

acclimation

Answer 15

A gradual, reversible, physiological adjustment that occurs in response to an environmental change.

Birds and mammals can usually tolerate more adverse temps. than reptiles.

Question 16

biome

Answer 16

A major terrestrial or aquatic life zone, characterised by vegetation type in terrestrial biomes or the physical environment in aquatic biomes.

Question 17

aquatic biomes

Answer 17

Occupies over 75% of Earth’s surface; determined by their salinity and other physical factors.

• Freshwater biomes - salinity < 1%
• Marine biomes - salinity around 3%

Question 18

freshwater biomes

Answer 18

Less than 1% of Earth and contain 0.01% of its water; harbour around 6% of all known species.

Relies for drinking water, crop irrigation, sanitation, and industry.

2 groups:

1) Standing water - lakes and ponds
2) Flowing water - rivers and streams

Question 19

Lakes and Ponds: photic zone

Answer 19

Shallow water near shore and upper layer of water away from shore; light is available for photosynthesis.

Question 20

Lakes and Ponds: aphotic zone

Answer 20

Deeper water and has light levels too low to support photosynthesis.

Question 21

Lakes and Ponds: benthic realm

Answer 21

Bottom of all aquatic biomes. Made up of sands, and organic and inorganic sediments.

Occupied by algae, aquatic plants, worms, insect larvae, molluscs, and microorganisms.

Question 22

phytoplankton

Answer 22

Microscopic algae and cyanobacteria that drift near the surfaces of aquatic biomes;regulated by the nitrogen and phosphorus.

Question 23

rivers and streams

Answer 23

Near the source: cold water, low in nutrients, and clear

Downstream: warmer, murkier , wider, and slower

Question 24

wetland

Answer 24

Transitional biome between an aquatic ecosystem and a terrestrial one.

Covered in water either permanently or periodically; support the growth of aquatic plants; rich in species diversity.

Migrating waterfowl and other birds depends on wetlands “pit stops” for food and shelter.

Provide water storage, reduce flooding, and improves water quality (traps pollutants in their sediments).

Question 25

marine biomes: pelagic realm

Answer 25

All the open water of the oceans.

Seafloor is known as the benthic realm.

Question 26

zooplankton

Answer 26

Free-floating animals, including microscopic ones. (abundant in the pelagic photic zone)

Question 27

marine biomes: coral reef biome

Answer 27

Occurs in the photic zone of warm tropical waters.

-Built up slowly by successive generations of coral animals (cnidarians that secrete a hard external exoskeleton) and by multi-cellular algae encrusted with limestone.

• Support a huge variety of invertebrates and fishes.
• Imperils by ocean acidification and rising sea surface temperatures.

Question 28

intertidal zone

Answer 28

Where ocean meets land.

-Home to many sedentary organisms, such as sea stares, barnacles, and mussels, which attach to rocks to prevent getting washed away.

Question 29

estuaries

Answer 29

Transition area between a river and the ocean.

• Salinity ranges vastly.
• Enriched by nutrients from rivers, among the most productive areas on Earth.
• Crucial nesting and feeding areas for waterfowl.

Question 30

tropics

Answer 30

The region from the Tropic of Cancer to the Tropic of Capricorn.

Question 31

temperate zones

Answer 31

Latitudes between the tropics and the Arctic Circle and the Antarctic Circle.
-Milder climates than the tropics or the polar regions.

Question 32

Mountain affect climate in 2 major ways:

Answer 32

1) Air temperature drops as elevation increases.
2) Mountains can block the flow of cool, moist air from a coast and cause radically different climates on opposing side of a mountain range.

Question 33

Tropical forests

Answer 33

Occur in equatorial areas; temperature is warm year-round.

-The layered structure of tropical rain forests provide many different habitats; treetops provide closed canopies over layers of small trees and a shrub understory.

Question 34

savannas

Answer 34

Dominated by grasses ans scattered trees; warm year-round; experience rainfall of 30-50 cm w/ dramatic seasonal variation.

• Fire, cause by lightening or human activity is an important abiotic factor.
• Home to largest grazing mammals and their predators.
• Most dominant plant-eaters agree insects like ants and termites.

Question 35

deserts

Answer 35

Driest of all biomes; low and unpredictable rainfall, < 30cm; may be very hot or relatively cold.

• Vegetation include water-storing plants like cacti and deeply rooted shrubs.
• Inhabitants include various snakes, lizards, seed-eating insects; adapted to mechanisms that conserve water.

Question 36

chaparral

Answer 36

Results mainly from cool ocean currents circulating offshore and producing mild, rainy, winters and hot dry summers.

• Limited to small coastal areas. (California, Mediterranean Sea)
• Vegetation adapted to periodic fires caused by lightening. (Contain flammable chemicals)

Question 37

temperate grasslands

Answer 37

Similar to tropical savannas. but are mostly treeless, except along rivers or streams; found in regions of relatively cold winter temperatures.

• 25-75cm per year; frequent severe droughts and too low to support forest growth.
• Periodic fires and grazing by large mammals prevent invasion by woody plants.
• Many birds nest on the ground.

Question 38

temperate broadleaf forest

Answer 38

Occurs throughout midlatitudes where there is sufficient moisture to support the growth of large trees.

• 75-100cm
• Temperature varies seasonally, hot summers and cold winters.
• In Northern Hemisphere, dense strands of deciduous trees drop their leaves before winter.
• Invertebrates live in the soil and thick layer of leaf litter.
• Mammals enter hibernation and some birds migrate.
• Cut for limber or cleared for agriculture or development.

Question 39

coniferous forests

Answer 39

In the Northern Hemisphere:

• cone-bearing evergreen trees
• includes the northern coniferous forests, or taiga, the largest terrestrial biome on Earth

Question 40

temperate rain forests

Answer 40

Found along coastal North America from Alaska to Oregon and are also coniferous forests.

Question 41

tundra

Answer 41

Expansive areas of the Arctuc between the taiga ans polar ice; permafrost, cold, high winds, very little precipitation.
-small shrubs, grasses, mosses, and lichens

Question 42

permafrost

Answer 42

Permanently frozen subsoil.

Question 43

alpine tundra (tundra cont…)

Answer 43

Occurs in high mountain tops at all latitude due to high winds and cold temperatures. No permafrost.

Question 44

polar ice

Answer 44

Land at high latitudes north of the arctic tundra in the Northern Hemisphere and in Antarctica in the Southern Hemisphere.

• only small parts that is free of ice or snow
• mosses and lichens
• nematodes, mites, and wingless springtails

Sea ice provides feeding platforms for large animals (polar bears in N.H. or penguins in S.H., and seals).

Question 45

polar marine biome (polar ice cont…)

Answer 45

Food sustaining polar birds and mammals,
-penguins feed at sea (squids, krill and other fish)

Antarctic krill are an important food sources for various species (fish, seals, squids, seabirds, penguins, and filter-feeding whales) and they depend on sea ice for breeding and refuge from predators.