Biology: Energy Flow in Ecosystems

Question 1

State that the Sun is the principal source of energy input to biological systems.

Answer 1

The Sun is the principal source of energy input to biological systems.

Question 2

Food Chain

Answer 2

the flow of energy (food) from one organism to the next, beginning with a producer

Question 3

Food Web

Answer 3

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

Question 4

Producer

Answer 4

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

Question 5

Consumer

Answer 5

An organism that gets its energy by feeding on other organisms

Question 6

Herbivore

Answer 6

An animal that gets its energy by eating plants

Question 7

Carnivore

Answer 7

An animal that gets its energy by eating other animals.

Question 8

Describe the carbon cycle.

Answer 8

The carbon cycle is the process in which carbon travels from the atmosphere into organisms and the Earth and then back into the atmosphere. Plants take carbon dioxide from the air and use it to make food. Animals then eat the food and carbon is stored in their bodies or released as CO2 through respiration.

Question 9

Describe energy losses between trophic levels.

Answer 9

Energy is lost through the levels of the food chain through not consuming all of the animal, urine and heat loss.

Question 10

Decomposer

Answer 10

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

Question 11

Ecosystem

Answer 11

Unit containing all of the organisms and their environment, interacting together, in a given area, e.g. decomposing log or a lake

Question 12

Trophic Level

Answer 12

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

Question 13

Explain why food chains usually have fewer than five trophic levels.

Answer 13

Due to energy loss, the top of the food chain with more than five trophic levels does not gain a lot of energy.

Question 14

Discuss the effects of the combustion of fossil fuels and the cutting down of forests on the oxygen and carbon dioxide concentrations in the atmosphere.

Answer 14

Combustion of fuels results in carbon dioxide and nitrous oxides being released into the atmosphere. These contribute to overall global warming. Deforestation increases the amount of carbon dioxide in the atmosphere; this is because there are no more trees to use carbon dioxide for photosynthesis.