Section 15.3- Nutritional Relationships in an Ecosystem

Question 1

the welfare of an ecosystem depends on

Answer 1

1. flow of energy
2. recycling of nutrients

Question 2

organisms that make their own food using an inorganic energy source

Answer 2

autotrophs

Question 3

obtain energy from sunlight

Answer 3

photoautotrophs

Question 4

autotrophs that obtin energy from chemical substances rather than sunlight

Answer 4

chemoautotrophs

Question 5

all other organisms that aren’t autotrophs are

Answer 5

heterotrophs (consumers)

Question 6

consumer that feed on plants

Answer 6

herbivores

Question 7

consumers that feed on other animals

Answer 7

carnivores

Question 8

consumers that feed on both plants and animals

Answer 8

omnivores

Question 9

bacteria and fungi that feed on detritus by secreting enzymes that break it down into simpler molecules

Answer 9

decomposers

Question 10

feed on detritus but cannot actually convert the detritus into a soil component

Answer 10

detritivores

Question 11

a classification that describes its feeding relationship to other organisms in its ecosystem

Answer 11

trophic level

Question 12

represent the first trophic level, being the producers

Answer 12

plants

Question 13

represent the second trophic level

Answer 13

herbivores

Question 14

represent the third trophic level

Answer 14

carnivores

Question 15

in a fourth trophic level, there is a carnivore at the top of the food chain called the

Answer 15

top carnivore

Question 16

model used by ecologists to show the nutritional relationships among organisms in an ecosystem

Answer 16

food chain

Question 17

living things are classified into trophic levels by their

Answer 17

position in the food chain

Question 18

because herbivores eat plants directly, they are called

Answer 18

primary consumers

Question 19

animals that eat herbivores are

Answer 19

secondary consumers

Question 20

the function or occupation of a living thing is its

Answer 20

niche

Question 21

not all of the ________________ that reaches the earth’s surface enters the food chain

Answer 21

solar energy

Question 22

the amount of energy available at the end of the food chain is only a

Answer 22

small percentage of the energy available in the producer

Question 23

one helpful way to represent information about an ecosystem is to construct a

Answer 23

pyramid diagram

Question 24

three types of pyramid diagrams ecologists use to illustrate the transfer of energy and distribution or organisms at different trophic levels is an ecosystem

Answer 24

energy pyramid
biomass pyramid
number pyramid

Question 25

pyramid diagram that shows the energy transferred from on trophic level to the next

producers form base and consumers form successive levels

Answer 25

energy pyramid

Question 26

pyramid diagram that represents the total mass of living matter per unit area at each trophic level

Answer 26

biomass level

Question 27

some biomass pyramids are exceptions because they are

Answer 27

inverted (smallest biomass on bottom)

Question 28

pyramid diagram that represents the number fo organisms at each trophic level and shows that population size usually decreases at each higher trophic level

Answer 28

number pyramid

Question 29

those that eat secondary consumers

Answer 29

tertiary consumers

Question 30

only __________ of energy at one trophic level is used by next trophic level

Answer 30

10%

Question 31

total mass of living matter per unit area

Answer 31

biomass