Topic 4.2 - energy flow

Question 1

Ecosystems source of energy

Answer 1

Energy in ecosystems start from autotrophs and their energy comes from the light energy supplied by the sun.

Question 2

Energy conversions in organisms: light

Answer 2

Light energy -> chemical energy (photosynthesis)

Question 3

Energy conversions in organisms: chemical

Answer 3

Chemical energy -> heat energy
Chemical energy -> electrical energy (nervous system)
Chemical energy -> kinetic energy (muscle contraction)

Question 4

Energy conversions in organisms: heat

Answer 4

Doesn’t exist so heat is lost in ecosystems.

Question 5

Trophic levels

Answer 5

The amount of levels are limited and the biomass of trophic levels reduce as you go up trophic levels as energy is lost between levels.

Question 6

Energy losses

Answer 6

Energy can be lost through many ways:
• Respiration
• Indigestible material lost through feces
• Not all material is consumed (ie bones)