Chapter 3

Question 1

Troposphere

Answer 1

extends only about 17 kilometers (11 miles) above sea level

Question 2

Greenhouse gasses

Answer 2

The remaining 1% of the air includes water vapor, carbon dioxide, and methane ; absorb and release
energy that warms the lower atmosphere

Question 3

Stratosphere

Answer 3

The next layer, stretching 17–50 kilometers (11–31

miles) above the earth’s surface

Question 4

Hydrosphere

Answer 4

consists of all of the water on or near the earth’s surface

Question 5

Geosphere

Answer 5

consists of the earth’s intensely hot

core, a thick mantle composed mostly of rock, and a thin outer crust

Question 6

Atmosphere

Answer 6

a thin spherical envelope of gases surrounding the earth’s surface

Question 7

Biosphere

Answer 7

consists of the parts of the atmosphere,

hydrosphere, and geosphere where life is found

Question 8

natural greenhouse effect

Answer 8

The vibrating gaseous molecules then have higher kinetic energy, which helps to warm the lower atmosphere and the earth’s surface

Question 9

Ecology

Answer 9

the science that focuses on how organisms interact with one another and with their nonliving environment of matter and energy

Question 10

Organism

Answer 10

An individual living being

Question 11

Populations

Answer 11

group of individuals of the same species living in a

particular place

Question 12

Community

Answer 12

Populations of different species living in a particular

place, and potentially interacting with each other

Question 13

Ecosystems

Answer 13

community of different species interacting with one
another and with their nonliving environment of
matter and energy

Question 14

Tropic level

Answer 14

Feeding level

Question 15

Producers or Autotrophs

Answer 15

make the nutrients they need from compounds

and energy obtained from their environment

Question 16

Photosynthesis

Answer 16

plants typically capture about 1% of the solar energy that falls on their leaves and use it in combination with carbon dioxide and water to form organic molecules, including energy-rich carbohydrates (such as glucose, C6 H12 O6), which store the chemical energy they need

Question 17

Chemosynthesis

Answer 17

few producers, mostly specialized bacteria, can convert simple inorganic compounds from their environment into more complex nutrient compounds without using sunlight

Question 18

Consumers or heterotrophs

Answer 18

that cannot produce the nutrients they need through photosynthesis or other processes

Question 19

Primary consumers or herbivores

Answer 19

are animals that eat mostly green plants

Question 20

Carnivores or secondary consumers

Answer 20

Animals that eat meat

Question 21

tertiary (or higher-level) consumers

Answer 21

that feed on the flesh of other carnivores

Question 22

Omnivores

Answer 22

such as pigs, rats, and humans eat plants and other animals

Question 23

Decomposers

Answer 23

are consumers that, in the process of obtaining their own nutrients, release nutrients from the wastes or remains of plants and animals and then
return those nutrients to the soil, water, and air for
reuse by producers

Question 24

detritus feeders or detritivores

Answer 24

feed on the wastes or dead bodies of other organisms

Question 25

Aerobic respiration

Answer 25

which uses oxygen to convert glucose back into carbon dioxide and water

Question 26

anaerobic respiration or fermentation

Answer 26

Some decomposers get the energy they need by

breaking down glucose (or other organic compounds) in the absence of oxygen

Question 27

Food chain

Answer 27

A sequence of organisms, each of which serves as a source of food or energy for the next

Question 28

Food web

Answer 28

form a complex network of interconnected food chains

Question 29

Biomass

Answer 29

the dry weight of all organic matter contained in its organisms

Question 30

Pyramid of energy loss

Answer 30

illustrates this energy loss for a simple food chain, assuming a 90% energy loss with each transfer.

Question 31

Gross primary productivity (GPP)

Answer 31

is the rate at which an ecosystem’s producers (usually plants) convert solar energy into chemical energy in the form of biomass found in their tissues

Question 32

Net primary productivity (NPP)

Answer 32

the rate at which producers use photosynthesis to produce and store chemical
energy minus the rate at which they use some of this stored chemical energy through aerobic respiration

Question 33

biogeochemical cycles or nutrient cycles

Answer 33

The elements and compounds that make up nutrients move continually through air, water, soil, rock, and living organisms within ecosystems, as well as in the biosphere in cycles

Question 34

hydrologic cycle or water cycle

Answer 34

collects, purifies, and distributes the earth’s fixed supply of water

Question 35

Carbon cycle

Answer 35

Various compounds of carbon circulate through the biosphere, the atmosphere, and parts of the
hydrosphere

Question 36

Phosphors cycle

Answer 36

Compounds of phosphorous (P) circulate through water, the earth’s crust, and living organisms

Question 37

Sulfur cycle

Answer 37

Sulfur circulates through the biosphere