Energy
Energy in an ecosystem originally comes from the __________.
What is the Sun?
It is released as heat and cannot be reused by organisms.
What is food?
Autotrophs make their own food by using __________.
Energy (sunlight or chemicals).
A food chain shows how __________ moves.
What is energy?
Biomass means the amount of __________ in a trophic level.
Living tissue.
Energy is lost at each trophic level as __________.
What is Heat?
An herbivore gets energy by eating __________.
What are plants?
Chemosynthesis uses energy from __________ instead of sunlight.
Chemical compounds (like hydrogen sulfide).
Phytoplankton are producers found in the __________.
Ocean.
Detritivores eat __________ matter.
Dead/decaying matter.
Only about _____% of energy is passed on to the next trophic level.
What is 10%?
Which level of an energy pyramid has the most energy available?
Producers (first trophic level).
Name one autotroph that is not a plant.
Bacteria
Place these in correct order: shark → phytoplankton → fish.
Phytoplankton → fish → shark.
Why is biomass greatest at the producer level?
Producers generate energy for all higher levels.
Explain why top predators get the least energy in an ecosystem.
They are farthest from the producers, and energy is lost as heat at every transfer.
Explain the difference between a primary and a secondary consumer.
Primary consumers eat producers; secondary consumers eat primary consumers.
Explain one similarity between photosynthesis and chemosynthesis.
Both produce energy-rich carbohydrates for organisms.
Why are food chains usually short (3–5 steps)?
Energy decreases at each level, so there's not enough to support many levels.
Explain how detritivores support nutrient cycling.
They break down dead material and return nutrients to the soil.
Why can energy not be recycled in an ecosystem?
It is released as heat and cannot be reused by organisms.
Why would a decrease in producers cause the entire food web to collapse?
Producers supply the base energy for all other trophic levels.
Explain one difference between ecosystems that rely on photosynthesis and those that rely on chemosynthesis.
Explain one difference between ecosystems that rely on photosynthesis and those that rely on chemosynthesis.
Explain why phytoplankton are considered the most important producers on Earth.
They produce most of the planet’s oxygen and serve as the base of marine food webs.
In an ecosystem, biomass decreases as you move up the pyramid. Explain why using the 10% rule.
Only 10% of energy moves up each level, so less energy means fewer organisms can be supported.