Communities and Ecosystems

Question 1

What abiotic factors do organisms need to adapt to?

Answer 1

– energy sources,
– temperature,
– the presence of water,
– inorganic nutrients, and
– other aquatic and terrestrial factors

Question 2

Pelagic Realm

Answer 2

All open water

Question 3

Benthic realm

Answer 3

Sea floor

Question 4

Aphotic zone

Answer 4

insufficient light for
photosynthesis

Question 5

Photic zone

Answer 5

where photosynthesis by phytoplankton and multicellular algae can occur.

Question 6

Zooplankton

Answer 6

are abundant in the pelagic photic zone.

Question 7

Coral reefs

Answer 7

Occur in the Photic zone

Question 8

Intertidal zone

Answer 8

are where the ocean meets the land and the shore is pounded by waves during high tide
and exposed to the sun and drying winds during low tide.

Question 9

Estuaries

Answer 9

are productive areas where a freshwater stream or river merges with the ocean.

Question 10

Wetlands

Answer 10

are transitional between aquatic and terrestrial ecosystems.

Question 11

What 2 categories do freshwater fall into?

Answer 11

1. Standing water biomes (lakes and ponds)
2. Flowing water biomes (rivers and streams)

Question 12

Does warm or cold air contain more moisture?

Answer 12

Warm

Question 13

Features of tropical forests

Answer 13

occur in equatorial areas,
– experience warm temperatures and days that are 11–12 hours long year-round, and
– have variable rainfall.

Question 14

Brackish water

Answer 14

Water that contains salinity levels between that of the ocean and that of freshwater. ie. Salt marshes

Question 15

Features of Savannas

Answer 15

– are warm year-round,
– have 30–50 cm annual rainfall,
– experience dramatic seasonal variation,
– are dominated by grasses and scattered trees, and
– have insects as the dominant herbivores.

Question 16

Features of deserts

Answer 16

are the driest of all terrestrial biomes.
– They typically have low and unpredictable rainfall.
– The cycles of growth and reproduction in the desert are
keyed to rainfall.
– Deserts can be very hot or very cold.

Question 17

Desertification

Answer 17

the conversion of semi-arid regions to
desert, is a significant environmental problem.

Question 18

Features of chaparral

Answer 18

characterized by dense, spiny shrubs
with tough, evergreen leaves.
– mild, rainy winters,
– hot, dry summers, and
– vegetation adapted to periodic fires. Firestorms that
race through the densely populated canyons of
Southern California can be devastating.

Question 19

Features of temperate grassland/prairies

Answer 19

are mostly treeless, except along rivers or streams,
– are found in regions of relatively cold winter
temperatures,
– experience precipitation of about 25–75 cm per year,
with periodic droughts, and
– in North America have historically been grazed by large
bison and pronghorn.

Question 20

Features of temperate forests

Answer 20

• Temperate broadleaf forests
  – grow where there is sufficient moisture to support the
  growth of large trees,
  – experience wide-ranging temperatures, and
  – have high annual precipitation (75–150 cm).
• These forests typically have a growing season of five to six
  months and a distinct annual rhythm.
• The canopy of a temperate broadleaf forest is more open
  than that of a tropical rain forest, and the trees are not as
  tall or as diverse.

Question 21

Features of coniferous forests/taiga

Answer 21

the largest
terrestrial biome on Earth. The taiga is characterized by
– long, cold winters and
– short, wet summers.

Question 22

Features of tundra

Answer 22

covers expansive areas of the Arctic between
the taiga and the permanently frozen polar ice.
* The treeless arctic tundra
– is characterized by permafrost, continuously frozen
subsoil, and
– may receive as little precipitation as some deserts.

Question 23

Features of Polar Ice

Answer 23

covers
– land north of the tundra,
– much of the Arctic Ocean, and – the continent of Antarctica.
• Temperatures are extremely cold year-round and precipitation is very low.
• The terrestrial polar biome is closely interconnected with the neighboring marine biome.

Question 24

Ecology

Answer 24

is the scientific study of the interactions of organisms and the environment.

Question 25

Organisms can potentially be affected by many different variables, grouped into two major types.

Answer 25

1. Bioticfactors
2. Abioticfactors

Question 26

1. Bioticfactors

Answer 26

include all of the organisms in an area, the living component of the environment.

Question 27

2. Abioticfactors

Answer 27

are the environment’s nonliving component, the physical and chemical factors.

Question 28

An organism’s habitat includes?

Answer 28

the biotic and abiotic factors present in its surroundings.

Question 29

To be successful, organisms must be adapted to the abiotic factors present in their environments.
• Major factors include:

Answer 29

– energy sources,
– temperature,
– the presence of water,
– inorganic nutrients, and
– other aquatic and terrestrial factors.

Question 30

Ecologists study interactions at several levels:

Answer 30

– organism
– population
– community
– ecosystem

Question 31

Humans rely upon natural ecosystems to:

Answer 31

– supply fresh water and some foods,
– recycle nutrients,
– decompose wastes, and
– regulate climate and air quality.

Question 32

• Wetlands

Answer 32

– buffer coastal populations against tidal waves and hurricanes,
– reduce the impact of flooding rivers, and
– filter pollutants.

Question 33

Natural vegetation helps to…

Answer 33

– retain fertile soil and
– prevent landslides and mudslides.

Question 34

Community Includes All the Organisms Inhabiting a Particular Area

Answer 34

• In the hierarchy of life, a population is a group of interacting individuals of a particular species.
• The next step up is a biological community, an assemblage of all the populations of organisms living close enough together for potential interaction.

Question 35

ecosystem consists of….

Answer 35

– all the organisms in a community and
– the abiotic environment with which the organisms interact.

Question 36

In an ecosystem:

Answer 36

– energy flow moves through the components of an
ecosystem and
– chemical cycling is the transfer of matter within the
ecosystem.

Question 37

Ecosystems are supplied with a continual influx of energy from the sun and Earth’s interior. Except?

Answer 37

for meteorites, there are no extraterrestrial sources of chemical elements.

Question 38

Biogeochemical cycles include

Answer 38

– biotic components

– abiotic components

– abiotic reservoirs

Question 39

– biotic components

Answer 39

§ Organisms, anything living

Question 40

– abiotic components

Answer 40

§ Rock, sand, water, minerals, wind

Question 41

– abiotic reservoirs

Answer 41

§ where chemicals accumulate or are stockpiled outside of living organisms.

Question 42

True or false, The Carbon Cycle Depends on Photosynthesis and Respiration?

Answer 42

• Carbon
– is the major ingredient of all organic molecules,
– has an atmospheric reservoir,
– cycles globally, and
– resides in plant and animal biomass, fossil fuels, soils,
sedimentary rocks, and as dissolved carbon.

Question 43

The Nitrogen Cycle Depends on
Bacteria, true or false?

Answer 43

• Nitrogen is
– an ingredient of proteins and nucleic acids,
– essential to the structure and functioning of all
organisms, and
– a crucial and often limiting plant nutrient.

Question 44

• Nitrogen has two abiotic reservoirs

Answer 44

1.the atmosphere, of which about 80% is nitrogen gas, and
2. soil.

Question 45

Nitrogen fixation

Answer 45

converts N2 to compounds of nitrogen that can be used by plants.
Various bacteria in soil (and root nodules of some plants) convert gaseous N2 to compounds that plants can use, such as ammonium (NH4+) and nitrate (NO3−).

Question 46

Every group of organisms plays a role in a given ecosystem, true or false?

Answer 46

True

Question 47

Biodiversity includes:

Answer 47

1. ecosystem diversity,
2. species diversity,and
3. genetic diversity.

Question 48

Keystone species
• organism that helps define an entire ecosystem.

Answer 48

• Without its keystone species, the ecosystem would be
dramatically different or cease to exist altogether.

Question 49

Most biodiversity loss is traced to four major threats:

Answer 49

– Habitat loss
– Introduced species
– Overharvesting
– Global climate chang

Question 50

Introduced species

Answer 50

are those that humans move from native locations to new geographic regions, either intentionally or by accident

Question 51

Overharvesting

Answer 51

is harvesting of organisms at rates exceeding the ability of their populations to rebound

Question 52

Conservation biology

Answer 52

is a goal-driven science that seeks to understand and counter the rapid loss of biodiversity

Question 53

Bioremediation

Answer 53

is the use of organisms—mainly prokaryotes, fungi, or plants—to detoxify polluted ecosystems

Question 54

Biological augmentation

Answer 54

uses organisms to add essential materials to a degraded ecosystem