Chapter 55

Question 1

Ecosystem

Answer 1

The basic units of ecology, made up of individual communities and their abiotic environments

Question 2

earth’s largest ecosystem is the

Answer 2

biosphere

Question 3

Energy enters an ecosystem as

Answer 3

radiant energy (sunlight)

Question 4

___ is trapped and used by producers for photosynthesis

Answer 4

less than 1%

Question 5

as work is accomplished,

Answer 5

energy dissipates into the environment as heat

Question 6

Primary producers

Answer 6

capture the sun’s energy through photosynthesis and incorporate the chemicals they manufacture into their own biomass

Question 7

consumers

Answer 7

extract energy from organic molecules produced by other organisms

Question 8

Herbivores

Answer 8

consumers that eat plants

Question 9

Carnivores

Answer 9

eat herbivores or other animals

Question 10

Omnivores

Answer 10

eat a variety of organisms, both plant and animal

Question 11

Detritivores

Answer 11

eat detritus

Question 12

Decomposers

Answer 12

break down organic remains and release simple inorganic molecules used by producers

Question 13

trophic level

Answer 13

in a food web influences other trophic levels to which it is not directly linked

Question 14

biomass is reduced by an average of ___ at each trophic level

Answer 14

90%

Question 15

Pyramids of Biomass

Answer 15

shows the amount of living material at each trophic level, which indicates the amount of fixed energy at a particular time

Question 16

Energy pyramids always have

Answer 16

large bases and get progressively smaller through succeeding trophic levels

showing that most energy dissipates into the environment when there is a transition from one trophic level to the next

Question 17

Tropical rain forest

Answer 17

have the highest productivity

Question 18

the least productive terrestrial ecosystem are

Answer 18

tundra and desert

Question 19

wetlands connect ___ and ___ environments and are extremely productive

Answer 19

wetlands connect terrestrial and aquatic environments and are extremely productive

Question 20

The most productive aquatic ecosystems are

Answer 20

algal beds, coral reefs, and estuaries

Question 21

The Carbon Cycle

Answer 21

The global movement of carbon between the abiotic environment and organisms

Question 22

Major processes that move carbon from the abiotic environment into organisms include

Answer 22

photosynthesis and the productin of shells by marine organisms

Question 23

Carbon is returned to the environments by

Answer 23

cellular respiration, decomposition, and combustion of wood or fossil fuels

Question 24

Carbon is stored for long periods in

Answer 24

wood, fossil fuels, and marine sediments

Question 25

The Nitrogen Cycle Steps

Answer 25

1. Nitrogen fixation
2. Nitrification
3. Assimilation
4. Ammonification
5. Denitrification

Question 26

Earths atmosphere is ___% N2 which does not readily combine with other elements

Answer 26

78% N2

Question 27

Nitrogen fixation

Answer 27

Converts n2 Gas to ammonia

nitrogen fixing bacteria use nitrogenase to break up molecular nitrogen

Question 28

Rhizobium form

Answer 28

nodules on roots of legumes

Question 29

Nitrification

Answer 29

converts ammonia or ammonium to Nitrate (NO3-)

Question 30

assimilation

Answer 30

the incorporation of nitrogen compounds by plants or animals into their own proteins and nucleic acids

Question 31

Ammonification

Answer 31

converts organic nitrogen compounds into ammonia and ammonium

Question 32

ammonifying bacteria perform ammonification in both

Answer 32

the soil and aquatic environments

Question 33

Denitrification

Answer 33

The reduction of NO3- to N2

Question 34

Denitrifying bacteria are

Answer 34

anaerobic

Question 35

The hydrolytic Cycle

Answer 35

Water continuously moves from the ocean to the atmosphere, to land, and back to the ocean

Question 36

transpiration

Answer 36

loss of water vapor from land plants

Question 37

runoff

Answer 37

movement of surface water from land to the ocean

Question 38

watershed

Answer 38

the area of land drained by runoff

Question 39

Groundwater eventually supplies water to

Answer 39

soil, streams and rivers, plants, and the ocean

Question 40

___ and ___ are the two abiotic factors that affect organisms in ecosystems the most

Answer 40

water and temperature

Question 41

The sun makes life on Earth possible

Answer 41

1. Warms the earth
2. Primary determinant of climate
3. photosynthesis
4. most fuels represent solar energy captured by photosynthetic organisms

Question 42

Rays strike almost ___ near the equator

Answer 42

vertically

Question 43

near the poles, the suns’s rays strike ___ and are spread over a larger surface area

Answer 43

obliquely

Question 44

March 21 to September 22

Answer 44

Earths Northern Hemisphere tilts toward the sun

Higher concentration of sunlight, longer days

Question 45

September 22 to March 21

Answer 45

The Northern Hemisphere tilts away from the sun

Lower concentration of sunlight, shorter days

Question 46

Earth’s atmosphere

Answer 46

Nitrogen 78% and Oxygen 21% make up 99% of dry air

Question 47

Other gases in earth’s atmosphere

Answer 47

Argon, carbon dioxide, neon, and helium

Question 48

The atmosphere performs essential ecological functions

Answer 48

1. Supplies organisms with oxygen
2. CO2
3. Protects Earth’s surface from most of the sun’s UV radiation and X-rays, and from cosmic rays from space
4. Interacts with solar energy to create weather and climate

Question 49

Four Global Oceans

Answer 49

Pacific, Atlantic, Indian, and Arctic Oceans

Question 50

Ocean currents

Answer 50

Prevailing winds blowing over the ocean produce movements of surface ocean waters

Question 51

surface ocean currents and winds tend to move

Answer 51

in the same direction

Question 52

Wildfires have several effects on organisms:

Answer 52

1. Combustion frees minerals locked in dry organic matter
2. Fire removes plant cover and exposes soil, stimulating seed germination and encouraging shade-intolerant plants
3. Removing plant cover leaves soil more vulnerable to wind and water, increasing soil erosion