Energy flow in ecosystems

Question 1

What is the principal source of energy input to biological systems?

Answer 1

The Sun

Question 2

Define ecosystem

Answer 2

A unit containing all of the organisms and their environment, interacting together, in a given area,

Question 3

Define trophic levels

Answer 3

The position of an organism in a food chain or food web.

Question 4

Define decomposer

Answer 4

An organism that gets its energy from dead or waste organic matter

Question 5

Define herbivore

Answer 5

An animal that gets its energy by eating plants

Question 6

Define carnivore

Answer 6

An animal that gets its energy by eating other animals.

Question 7

Define producer

Answer 7

An organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis

Question 8

Define consumer

Answer 8

An organism that gets its energy by feeding on other organisms

Question 9

Define food chain

Answer 9

The flow of energy (food) from one organism to the next beginning with a producer (e.g.mahogany tree → caterpillar → song bird → hawk)

Question 10

Define food web

Answer 10

A network of interconnected food chains showing the energy flow through part of an ecosystem

Question 11

Descries the energy losses between trophic levels

Answer 11

• Energy is lost through the process of respiration
• Energy is used up for movement
• Warm blooded animals loses heat energy through urines and faeces

Question 12

Give examples of the Sun being the principle source

Answer 12

Photosynthetic plants and some bacteria trap light energy and convert into chemical energy

• Organism eat plants or animals to obtain energy
• This energy is passed from one organism to another in food chain

Question 13

Describe the carbon cycle

Answer 13

• Plants take carbon dioxide out of the air by photosynthesis - convert carbon dioxide into organic materials
• Animals and plants release CO2 into the air by respiration
• Decomposers break down the organic molecules by respiration - also release carbon dioxide
• Combustion of fossil fuels releases CO2 back into the air.

Question 14

Discuss the effects of the combustion of fossil fuels and the cutting down of forest affect the concentration of O2 and CO2 in the atmosphere

Answer 14

Photosynthesis takes CO2 out of the atmosphere and replaces it with oxygen
Respiration and combustion use up O2 from the atmosphere and replace with CO2
- Combustion increase the percentage of carbon dioxide
-The loss of trees reduce the amount of photosynthesis
Concentration of CO2 increase and oxygen decrease