Chapter 3

Question 1

Biogeochemical cycle

Answer 1

Process where elements, chemical compounds, and other forms of matter are passed from one organism or biosphere to another

Question 2

Nutrient

Answer 2

Chemical substance needed by organisms to sustain life

Question 3

Nitrogen fixation

Answer 3

Process of converting nitrogen gas into nitrogen compounds for plants to absorb and use

Question 4

Denitrification

Answer 4

Process where bacteria converts nitrates into nitrogen gas

Question 5

Limiting nutrient

Answer 5

Single essential nutrient limiting productivity in an ecosystem

Question 6

Biosphere

Answer 6

Part of Earth where life exists

Contains land, water, and air or atmosphere

Question 7

Species

Answer 7

Group of similar organisms that can breed and produce fertile offspring

Question 8

Population

Answer 8

Group of the same species living in the same area

Question 9

Community

Answer 9

Assembly of different populations living in a defined area

Question 10

Ecology

Answer 10

Scientific study of interactions among organisms and their environment

Question 11

Ecosystem

Answer 11

All of the organisms living in a place together with their nonliving environment

Question 12

Biome

Answer 12

Group of ecosystems sharing similar climates and organisms

Question 13

Biotic factor

Answer 13

Any living part of an environment that organisms interact with

Question 14

Abiotic factor

Answer 14

Physical, nonliving factors that shape an ecosystem

Question 15

Autotroph

Answer 15

Organism that is able to capture energy from sunlight and chemicals to produce its own food from inorganic compounds

AKA: producer

Question 16

Primary producer

Answer 16

First producer of energy-rich compounds to be used by other organisms

Question 17

Photosynthesis

Answer 17

Process used by plants and autotrophs that captures light energy to power chemical reactions and turn CO2 and H2O into O2 and energy rich carbohydrates such as sugars and starches

Question 18

Chemosynthesis

Answer 18

Process where chemical energy is used to produce carbohydrates

Question 19

Heterotroph

Answer 19

Organism that obtains food by consuming other living things

AKA: consumer

Question 20

Consumer

Answer 20

Organism that relies on other organisms for energy and food

AKA: heterotroph

Question 21

Carnivore

Answer 21

Organism that eats only animals to obtain energy

Question 22

Herbivore

Answer 22

Organism that eats only plants to obtain energy

Question 23

Scavenger

Answer 23

Animal that consumes carcasses of other animals

Question 24

Omnivore

Answer 24

Organism that eats both plants and animals to obtain energy

Question 25

Decomposer

Answer 25

Organism that breaks down and obtains energy from dead organic matter

Question 26

Detritivore

Answer 26

Animal that eats dead plants and animals and other dead matter

Question 27

Food chain

Answer 27

Series of steps in an ecosystem where organisms transfer energy by eating and being eaten

Question 28

Phytoplankton

Answer 28

Photosynthetic algae found near the ocean surface

Question 29

Food web

Answer 29

Network of interactions formed by feeding relationships between various organisms in an ecosystem

Question 30

Zooplankton

Answer 30

Small, free-floating animals that form plankton

Question 31

Trophic level

Answer 31

Each step in a food chain or web

Question 32

Ecological pyramid

Answer 32

Illustration of relative amounts of energy and matter contained within each trophic level in a given food chain

Question 33

Biomass

Answer 33

Total amount of living tissue within a given trophic level