Biology Chapter 3

Question 0

List the levels of ecological organization, beginning with the lowest.

Answer 0

Species
Population
Community
Ecosystem
Biome
Biosphere

Question 1

What is ecology?

Answer 1

The scientific study of interactions among and between organisms in their environment.

Question 2

True or false: A population consists of all organisms in the same species.

Answer 2

True

Question 3

What are the three basic approaches scientists use to conduct modern ecological research?

Answer 3

Observing
Experimenting
Modeling

Question 4

True or false: Ecological models of the environment are extremely unreliable, so they are shunned by ecologists.

Answer 4

False (they are very common and useful)

Question 5

What is the main energy source for organisms that do not access the sun’s light?

Answer 5

Inorganic chemical compounds

Question 6

What is the difference between an autotroph and a heterotroph?

Answer 6

Autotrophs produce their own food while heterotrophs do not.

Question 7

What are plant and animal remains and other dead matter collectively called?

Answer 7

Detritus

Question 8

What do all different heterotrophs consume?

Answer 8

Herbivore- Plants
Carnivore- Meat
Omnivore- Plants and animals
Detrivore- Dead matter (detritus)
Decomposer- Breaks down organic matter

Question 9

What is a food chain?

Answer 9

A series of steps where organisms eat each other and get eaten

Question 10

What is a trophic level?

Answer 10

A step in a food chain

Question 11

What kinds of organisms make up the first trophic level?

Answer 11

Producers

Question 12

What is an ecological pyramid?

Answer 12

A diagram that shows the relative amounts of energy contained in each trophic level of a food web or chain.

Question 13

True or false: When heterotrophs consume producers, they only receive about 10% of their energy.

Answer 13

True

Question 14

What is biomass?

Answer 14

The total amount of living tissue within a given trophic level.

Question 15

What does a biomass pyramid represent?

Answer 15

The amount of potential food available for each trophic level.

Question 16

What does a pyramid of numbers show?

Answer 16

The number of relative organisms at each trophic level.

Question 17

What are the four main elements in the atmosphere?

Answer 17

Oxygen, carbon, hydrogen, and nitrogen

Question 18

Matter moves through an ecosystem in _____________.

Answer 18

Biogeochemical cycle

Question 19

What are chemical substances needed in order to sustain life?

Answer 19

Nutrients

Question 20

What are the three main nutrient cycles that take place in the biosphere?

Answer 20

Carbon cycle, nitrogen cycle, and phosphorus cycle

Question 21

Why is nitrogen required by all organisms?

Answer 21

Nitrogen helps make amino acids.

Question 22

What is nitrogen fixation?

Answer 22

The process of converting nitrogen gas into ammonia

Question 23

What is the process of converting nitrogen into nitrogen gas called?

Answer 23

Denitrificaiton

Question 24

Why is phosphorus essential to living things?

Answer 24

It forms part of life-sustaining molecules.

Question 25

What is primary productivity in an ecosystem?

Answer 25

The rate in which organic matter is created by producers.

Question 26

When does a nutrient become limiting?

Answer 26

When it is scarce or cycles slowly.

Question 27

When do algal blooms occur?

Answer 27

When aquatic ecosystems get lots of nutrients.