Chapter 14: Energy Flow in Ecosystems

Question 1

population

Answer 1

all the organisms of a particular species found in an ecosystem

Question 2

community

Answer 2

all the different species living in an ecosystem

Question 3

habitat

Answer 3

place within an ecosystem where specific organisms live

Question 4

ecosystem

Answer 4

a self-supporting system of organisms interacting with each other and their physical environment

Question 5

quadrat

Answer 5

a square frame used for sampling organisms

Question 6

How do you use a quadrat?

Answer 6

Lay out a tape measure to mark out a sampling field.
Use a random number generator to get some coordinates
Count the number of organisms present in the quadrat
Repeat with different coordinates
Calculate the mean and use it to estimate the entire population size

Question 7

trophic level

Answer 7

stage in a food chain

Question 8

producer

Answer 8

organism that can make its own food, first trophic level

Question 9

primary consumer

Answer 9

organism that obtains energy by feeding on producers, second trophic level

Question 10

secondary consumer

Answer 10

organism that obtains energy by feeding on primary consumer, third trophic level

Question 11

tertiary consumer

Answer 11

organism that obtains energy by feeding on secondary consumer, fourth trophic level

Question 12

decomposers

Answer 12

organism that breaks down organic material

Question 13

food chain

Answer 13

shows simple feeding relationships in ecosystem, direction of arrows shows energy transfer

Question 14

food web

Answer 14

shows complex feeding relationships within an ecosystem, direction of arrows shows energy transfer

Question 15

pyramids of numbers

Answer 15

represents the number of organisms in each trophic level in a food chain, may be smaller on bottom as irrespective of mass

Question 16

pyramids of biomass

Answer 16

represents the total mass of the organisms in each trophic level, looks like Egyptian pyramid

Question 17

pyramids of energy transfer

Answer 17

shows the energy transferred through each trophic level in a food chain

Question 18

How is energy transferred along food chains?

Answer 18

Food chains show the direction of energy, and transfer between the trophic levels. Energy is transferred as chemical energy. Chemical energy is stored as new biomass.

Question 19

Why is only 10% of energy transferred along trophic levels?

Answer 19

Between each trophic level in a food chain, not all energy is converted into new biomass. Much of the energy is lost, as not all is eaten, not all is digested, but instead excreted, some used for respiration, movement and controlling body temperature.

Question 20

Why do they use pest control in farms?

Answer 20

Pests are organisms that reduce the yield of crop planets and farm animals. Controlling them leads to a higher crop yield, and more profit.

Question 21

What are the advantages of using pesticides?

Answer 21

They are effective, and allow a higher crop yield.

Question 22

What are the disadvantages of using pesticides?

Answer 22

Using pesticides can lead to pesticide resistance, environmental damage and bioaccumulation.

Question 23

bioaccumulation

Answer 23

pesticides stored in fatty tissue

Question 24

What is biological pest control?

Answer 24

Using natural ways to get rid of pests

Question 25

What are the advantages of biological pest control?

Answer 25

The natural balance in the ecosystem is undisturbed. The predators do not allow the pests to come back, and it does not affect the population of other species.

Question 26

What are the disadvantages of biological pest control?

Answer 26

It is less effective, as pests are still able to reduce crop yield.

Question 27

fish farming

Answer 27

the raising of fish commercially in tanks or enclosures, usually for food

Question 28

How is water quality maintained in fish farming?

Answer 28

Water quality can be carefully monitored by temperature and oxygenation, and cleaned out by circulating water.

Question 29

What happens if water quality is not maintained?

Answer 29

Pollution of water with fish faeces and food pellets can lead to eutrophication, leading to fish death. To keep oxygen level constant

Question 30

How is intraspecific competition reduced?

Answer 30

No overcrowding by increasing cage size. Separate sizes or different age groups.

Question 31

How is interspecific competition reduced?

Answer 31

One species of fish per cage by using different cages. Stop other fish entering the cage by the size of mesh.

Question 32

How is disease spreading and removal of waste products avoided?

Answer 32

The water is circulated so that it is constantly of a good quality.

Question 33

How do fish farmers feed their fish and why?

Answer 33

They feed them small amounts of food at regular intervals at regular intervals so that less is wasted, and to prevent oxygen depletion via eutrophication.

Question 34

What are some advantages of fish farming?

Answer 34

Selective breeding programmes can be used to improve the quality of fish for characteristics like fast growth. They are protected against predators and parasites. It allows them to meet the shortfall of fish.

Question 35

What are some disadvantages of fish farming?

Answer 35

Habitat destruction by flooding or building. Attracts predators. Farm waste, chemicals, disease and parasites are released into the surrounding water, harming other marine life.

Question 36

How can a fish farmer help to increase the yield of fish?

Answer 36

Control predation by covering ponds with nets. Control disease by use of antibiotics. Control water quality by filtering out nitrogenous waste.