Lesson 2
How Do Living Things Get Energy?
• Photosynthesis is the process by which plants
(including algae) use sunlight to make sugar from
carbon dioxide and water.
– Producers (which include some single-celled
organisms) carry out this process
• Photosynthesis releases oxygen that other
animals (fish, snails, etc.) use to breathe.
– Respiration – the process of taking in oxygen and
releasing carbon dioxide to get energy
Sunlight + water + CO2
sugar + oxygen
Photosynthesis
Photosynthesis/Respiration Cycle
How Do Living Things Get Energy?
• Consumers - organisms that feed on other
organisms for energy.
– Animals, including fish and crickets
• Scavengers – animals that feed on the bodies
of dead organisms.
– Including isopods and snails
• Decomposers – an organism that helps to
break down and decay dead organisms and
the wastes of living organisms.
Plants & Animals
in our Ecocolumn
• Aquarium
– Duckweed – multiplies rapidly, but can cut off light from
other water plants
– Elodea – easy to grow and can survive in poor conditions,
but can clog waterways/crowd other plants
– Algae – comes in all sizes (microscopic to gigantic) and
many colors
– Mosquito Fish – strong; survive in wide range of temps;
don’t mind change; eat elodea and mosquito larvae
(immature mosquitos); live-bearers (fry born alive and
fully formed)
– Snail – a gastropod, soft body protected by shell, “foot”
that releases film of mucus to help it move; sees poorly,
cannot hear; reproduce by laying eggs; a scavenger
• Terrarium
Plants & Animals
in our Ecocolumn
– Isopod – name means “equal legs”; close relative
of the lobster, crab, shrimp; has an exoskeleton
which it molts (sheds) in order to grow; a
scavenger
– Cricket – long antennae help them feel, taste,
smell, detect humidity and temperature; male’s
wings are used for chirping; have two spines used
to sense vibrations in the air and ground; females
lay eggs