chapter 3

Question 1

biosphere

Answer 1

consists of all life (living and nonliving)

Question 2

ecology

Answer 2

study of interactions among organisms and between their physical environment

Question 3

biotic factor

Answer 3

any living part of the environment with which an organism might interact

Question 4

abiotic factor

Answer 4

any nonliving part of the environment

Question 5

ecological methods

Answer 5

observation, experimentation, modeling

Question 6

autotrophs

Answer 6

use solar or chemical energy to produce food by assembling inorganic compounds into complex organic molecules

Question 7

primary producers

Answer 7

first producers of energy rich compounds that are later used by other organisms (make their own food)

Question 8

photosynthesis

Answer 8

captures light energy and uses it to power chemical reactions that convert carbon dioxide and water into oxygen and energy carbohydrates such as sugars and starches.

Question 9

chemosynthesis

Answer 9

chemical energy is used to produce carbohydrates

Question 10

heterotrophs

Answer 10

must acquire energy from other organisms- by ingesting them

Question 11

consumers

Answer 11

organisms that rely on other organisms for energy and nutrients

Question 12

carnivores

Answer 12

kill and eat other animals

Question 13

scavengers

Answer 13

animals that consume the carcasses of other animals

Question 14

decomposers

Answer 14

feed by chemically breaking down organic matter

Question 15

herbivores

Answer 15

plant eating

Question 16

omnivores

Answer 16

eats plant and animals

Question 17

detritivores

Answer 17

digest decomposers that live on, and in detritus particles

Question 18

food chain

Answer 18

series of steps in which organisms transfer energy by eating and being eaten

Question 19

phytoplankton

Answer 19

floating algae

Question 20

food web

Answer 20

network of feeding interactions

Question 21

zooplankton

Answer 21

diverse group of small swimming animals

Question 22

trophic level

Answer 22

each step in a food web

Question 23

ecological pyramid

Answer 23

show the relative amount of energy or matter contained within trophic level in a food chain/web

Question 24

biomass

Answer 24

the total amount of living tissue within a given trophic level

Question 25

biogeochemical cycles

Answer 25

closed loops that elements pass through from one organism to another among parts of the biosphere

Question 26

nutrients

Answer 26

the chemical substances that an organism needs to sustain life

Question 27

nitrogen fixation

Answer 27

the process in which bacteria convert nitrogen gas into ammonia

Question 28

denitrification

Answer 28

bacteria obtains energy by converting nitrates into nitrogen gas through this process

Question 29

limiting nutrient

Answer 29

the nutrient whose supply limits productivity