Chapter 7

Question 1

biosphere

Answer 1

the sum total of all of Earth’s ecosystems

Question 2

ecosystem

Answer 2

all of the organisms in a given area plus the physical environment in which they interact

Question 3

habitat

Answer 3

the physical environment in which individuals of a particular species can be found.

Question 4

species

Answer 4

a group of plants or animals that have a high degree of similarity and can generally only interbreed among themselves

Question 5

niche

Answer 5

the role a species plays in its community, including how it gets its energy and nutrients, what habitat requirements it has, and what other species and parts of the ecosystem it interacts with.

Question 6

energy flow

Answer 6

the one-way passage of energy through an ecosystem

Question 7

nutrient cycles

Answer 7

movement of life’s essential chemicals of nutrients through an ecosystem (aka biogeochemical cycles)

Question 8

biomass

Answer 8

the sum of all organic material - plant and animal matter - that make up an ecosystem

Question 9

biome

Answer 9

one of many distinctive types of ecosystems determined by climate and identified by the predominant vegetation and organisms that have adapted to live there.

Question 10

limiting factor

Answer 10

the critical resource whose supply determines the population size of a given species in a given biome.

Question 11

range of tolerance

Answer 11

the range, within upper and lower limits, of a limiting factor that allows a species to survive and reproduce.

Question 12

biotic

Answer 12

the living (organic) components of an ecosystem, such as the plants and animals and their waste (dead leaves, feces).

Question 13

abiotic

Answer 13

the nonliving components of an ecosystem, such as rainfall and mineral composition of the soil.

Question 14

reservoirs (or sinks)

Answer 14

abiotic or biotic component of the environment that serves as a storage place for cycling nutrients.

Question 15

producer

Answer 15

an organism that converts solar energy to chemical energy via photosynthesis.

Question 16

consumer

Answer 16

an organism that obtains energy and nutrients by feeding on another organism.

Question 17

cellular respiration

Answer 17

the process in which all organisms break down sugar to release its energy, using oxygen and giving off CO2 as a waste product.

Question 18

carbon cycle

Answer 18

movement of carbon through biotic and abiotic parts of an ecosystem. Carbon cycles via photosynthesis and cellular respiration as well as in and our of other reservoirs such as the oceans and soil. It is also released by human actions such as fossil fuel burning.

Question 19

nitrogen cycle

Answer 19

continuous series of natural processes by which nitrogen passes from the air to the soil, to organisms, and then returns back to the air or soil through decomposition or denitrification.

Question 20

nitrogen fixation

Answer 20

conversion of atmosphere nitrogen into a biologically usable form, carried out by bacteria found in soil or via lightning.

Question 21

phosphorous cycle

Answer 21

series of natural processes by which the nutrient phosphorous moves from rock to soil or water, to living organisms, and back to the soil.