chapter 3

Question 1

what is the main energy source for life on Earth?

Answer 1

sun

Question 2

how much of the sunlight that reaches Earth’s surface is used by living things?

Answer 2

< 1%

Question 3

what is a source of energy used by organisms that don’t get energy from the sun?

Answer 3

energy stored in inorganic chemical compounds

Question 4

what are autotrophs/producers?

Answer 4

plants, some algae, and certain bacteria that can capture energy from sunlight/chemicals and use it to produce food

Question 5

how do autotrophs/producers work?

Answer 5

using energy from the environment, they fuel the assembly of inorganic compounds into complex organic molecules that combine to produce living tissue

Question 6

describe photosynthesis

Answer 6

autotrophs use sunlight to power chemical reactions that convert CO2; H2O into O; glucose/starches

Question 7

what is the main autotroph on land?

Answer 7

plants

Question 8

what is the main autotroph in freshwater ecosystems?

Answer 8

algae

Question 9

what is the main autotroph in wet land?

Answer 9

photosynthetic bacteria

Question 10

what is chemosynthesis?

Answer 10

when organisms rely on energy within bonds of an inorganic molecule to produce carbohydrates

Question 11

who performs chemosynthesis?

Answer 11

bacteria

Question 12

what is the difference between photosynthesis and chemosynthesis?

Answer 12

they use different types of energy

photosynthesis uses light energy and chemosynthesis uses chemical energy

Question 13

what are heterotrophs/consumers?

Answer 13

organisms that rely on others for their food and energy

Question 14

what are the different types of heterotrophs?

Answer 14

herbivores; carnivores; omnivores; detritivores; decomposers

Question 15

what are detritivores?

Answer 15

feed on dead matter called detritus (converted by a decomposer)

Question 16

what are some examples of detritivores?

Answer 16

mites, earthworms, snails, crabs

Question 17

what happens to an animals energy when it is eaten?

Answer 17

energy flows into the organism it was eaten by

Question 18

describe how energy flows through an ecosystem

Answer 18

from sun/inorganic compounds to autotrophs to heterotrophs

Question 19

what is a food chain?

Answer 19

steps in which organisms transfer energy by being eaten

Question 20

what do decomposers turn dead plant matter into?

Answer 20

detritus

Question 21

what is a trophic level?

Answer 21

a step in a food chain or web (producer being zeroth)

Question 22

what is an ecological pyramid?

Answer 22

energy:
diagram that shows amounts of original sunlight/chemical energy contained with each trophic level in a food chain; about 10% is transferred to next level (because most is used doing daily activities)

biomass:
simple diagram of most mass to least mass (bottom to top respectively)

numbers:
amount of individuals in a species