Chapter 13 - Principles in Ecology

Question 1

What is ecology? 13.1

Answer 1

The study of interactions among organisms (plants and animals) and their environment
Eco comes from Greek word “oikos” – house
-logy comes from “logos” – study of
Ecology means “study of the house” as coined by Ernst Haeckel

Question 2

What are the levels of organization in ecology in order? 13.1

Answer 2

Organism 
Population 
Community
Ecosystem 
Biome

Question 3

Organism 13.1

Answer 3

Individual living thing

ex. lion

Question 4

Population 13.1

Answer 4

group of same species that live in one area

ex. pride of lions

Question 5

Community 13.1

Answer 5

Collection of interacting populations

ex. Lions, antelope, zebras, elephants, grasses, etc.

Question 6

Ecosystem 13.1

Answer 6

Interactions of biotic and abiotic factors in an area

Question 7

What are biotic vs. abiotic factors? 13.2

Answer 7

Biotic factors—living or once living things (ex. Animals, plants, microorganisms, etc…)
Abiotic factors—nonliving things (ex. Sunlight, temperature, soil, etc…)

Question 8

Biome 13.1

Answer 8

Regional or global community of organisms which is usually characterized by the climate conditions and plant communities that thrive there

Question 9

What are keystone species? 13.2

Answer 9

One that has an unusually large effect on its ecosystem. (ex. Beaver) (ex. Killing too many deer during hunting season)

Question 10

Autotrophs vs. Heterotrops 13.3

Answer 10

Autotrophs—“self feeder”

Heterotrophs—“different feeder”

Question 11

Producers 13.3

Answer 11

Obtain energy from the sun or chemicals and convert it to a useable form of energy

Question 12

Consumers 13.3

Answer 12

Get their energy by eating other living or once-living organisms (like autotrophs and/or other heterotrophs)

Question 13

What are the 5 types of consumers? 13.4

Answer 13

Herbivores—obtain energy from eating plants
Omnivores—obtain energy from eating plants and animals
Carnivores—obtain energy from eating animals
Detritivores—obtain energy from eating detritus or dead organic material (ex. Earthworm)
Decomposers—obtain energy from breaking down organic matter (dead) into simpler molecules that can be more easily absorbed by decomposers and by other organisms

Question 14

Food Chain 13.4

Answer 14

A linear sequence that links species by their feeding relationships
Example: autotroph→heterotroph→decomposer
*Heat energy is lost in each step

Question 15

Trophic Levels 13.4

Answer 15

Levels of nourishment in a food chain
1st trophic level  producer (base)
2nd trophic level  primary (1’) consumer (herbivore), first order
3rd trophic level  secondary (2’) consumer (omnivore/carnivore), second order
4th trophic level  tertiary (3’) consumer (omnivore/ mostly carnivore), third order (top level)

Energy flows through an ecosystem in ONE direction

Question 16

Food Web 13.4

Answer 16

Links all the food chains in an ecosystem

Question 17

In an ecological pyramid, how much energy is transferred to the next trophic level? 13.4

Answer 17

10%

Question 18

Types of pyramids 13.4

Answer 18

An energy pyramid compares energy used by producers, primary consumers, and other trophic levels (in units of kilocalories, kcal) see figure 13.17 on page 418
A biomass pyramid provides a picture of the mass of producers needed to support primary consumers, the mass of primary consumers required to support secondary consumers, and so on.
A pyramid of numbers shows the numbers of individual organisms at each trophic level in an ecosystem.
Biomass pyramids and pyramids of numbers may occur in an inverted, or upside down formation.

Question 19

Hydrologic Cycle 13.5

Answer 19

Circular pathway of water on earth from the atmosphere, to the surface, below ground, and back

Question 20

What draws water back to earth? 13.5

Answer 20

Gravity

Question 21

What determines which plants grow where? 13.5

Answer 21

Amount of precipitation received by an area

Question 22

How much water enters the hydrologic cycle? 13.5

Answer 22

80%

Question 23

Biochemical Cycle 13.5

Answer 23

Movement of a particular chemical through the biological and geological, or living or nonliving, parts of an ecosystem