#20-Energy Flow And Food Webs

Question 1

What are tropic levels?

Answer 1

Describe the feeding positions of groups of organisms in ecosystem

Question 2

What are detivores?

Answer 2

Consumes feces and dead organisms

Question 3

What is allochthonous?

Answer 3

External energy inputs coming outside of the system and going into the system

Question 4

What is autochthonous?

Answer 4

Energy produced from within a system

Question 5

Energy _____ with every tropic level

Answer 5

Decreases

Question 6

What is a trophic pyramid?

Answer 6

Portrays the relative amounts of energy or biomass of each trophic level

Question 7

Are the pyramids in terrestrial and aquatic system ps the same?

Answer 7

Aquatic pyramid is inverted

- inverted pyramids occur when productivity is the lowest

Question 8

Do land herbivores consume more or less autotroph biomass than aquatic herbivores?

Answer 8

Yes

Question 9

What is herbivor production limited by?

Answer 9

By the food available

Question 10

3 reasons why herbivores don’t consume more biomass?

Answer 10

1. Constrained by predators
2. Autotrophs have defences against herbivory
3. Phytoplankton is more nutritious for herbivores then terrestrial plants

Question 11

What is trophic efficiency ?

Answer 11

Amount of energy at one level divided by the amount of energy at the trophic level immediately below it

Question 12

What is consumption efficiency?

Answer 12

Proportion of available energy that is consumed

Question 13

What is assimilation efficiency?

Answer 13

Proportion of ingested food that is assimilated

Question 14

What is production efficiency?

Answer 14

Proportion of assimilated food that goes into new consumer biomass

Question 15

Where does consumption efficiency the greatest?

Answer 15

Aquatic ecosystems

Higher carnivores

Question 16

What is assimilation efficiency determined by?

Answer 16

Food quality
Physiology of consumer
- more likely in carnivores

Question 17

Who digests food more efficiently?

Answer 17

Endothermic

- higher assimilation efficiency

Question 18

Where do endothermic allocate most of their energy to do?

Answer 18

To heat production

- less room for growth and reproduction

Question 19

What happens to the surface area to volume ratio as body size increases?

Answer 19

The ratio decreases

Question 20

What is bottom up control?

Answer 20

Resources that limit NPP determine energy flow through an ecosystem

Question 21

What is top down control?

Answer 21

Energy flows as governed by predator consumption rates at the highest trophic level. Which influence multiple trophic level below them

Question 22

How can the troop levels change?

Answer 22

By addition or loss of a top predator or s predator in the middle of the chain

Question 23

What are 3 factors that can control the number of trophic areas?

Answer 23

1. Amount of energy entering via primary production
2. Frequencies of disturbance
3. Ecosystem size
   - larger populations = more species diversity

Question 24

What are food webs?

Answer 24

Conceptual model of the trophic interactions of organisms in an ecosystem
-more species = more complex web

Question 25

Bioaccumulation

Answer 25

Can stay in the environment for a very long time

-in the tissues of organisms

Question 26

Biomagnification

Answer 26

Transferred up and can increase concentration a they are consumed

Question 27

What are ecological roles ?

Answer 27

Organisms are determined by their tropic interactions

- what they eat and what eats them