Energy Basics
What is the main source of energy in most ecosystems?
A) The Sun
B) Decomposers
C) Plants
D) Water
A) The Sun ✅
A cow eating grass is an example of a…
A) Herbivore
B) Carnivore
C) Omnivore
D) Detritivore
A) Herbivore ✅
What does a food chain show?
A) Energy flow through one path
B) Habitat size
C) Predator populations
D) Nutrient cycling
A) Energy flow through one path ✅
Which process removes CO₂ from the atmosphere?
A) Photosynthesis
B) Respiration
C) Combustion
D) Decomposition
A) Photosynthesis ✅
What is evaporation?
A) Liquid water changing into vapor
B) Groundwater moving into rivers
C) Water vapor turning to liquid
D) Vapor turning into precipitation
A) Liquid water changing into vapor ✅
Producers…
A) Eat other organisms
B) Store energy as fossils
C) Make their own food
D) Break down dead matter
C) Make their own food ✅
What do herbivores eat?
A) Meat
B) Plants
C) Dead matter
D) Both plants and animals
B) Plants ✅
In a food chain, arrows point…
A) In the direction of energy flow
B) Toward the sun
C) Toward the energy source
D) Randomly
A) In the direction of energy flow ✅
Which process adds CO₂ back into the atmosphere?
A) Photosynthesis
B) Transpiration
C) Respiration
D) Nitrogen fixation
C) Respiration ✅
Plants releasing water vapor is called…
A) Respiration
B) Condensation
C) Transpiration
D) Evaporation
C) Transpiration ✅
Why do we say energy “flows” instead of “cycles” in an ecosystem?
A) Energy is created and destroyed
B) Energy is reused over and over
C) Energy moves in one direction and decreases
D) Energy increases as it moves
C) Energy moves in one direction and decreases ✅
What is an omnivore?
A) Eats plants and animals
B) Breaks down dead matter
C) Eats animals only
D) Eats plants only
A) Eats plants and animals ✅
Which shows more complexity?
A) Predator-prey models
B) Food chains
C) Food webs
D) Energy pyramids
C) Food webs ✅
Burning fossil fuels releases CO₂. This is called…
A) Combustion
B) Photosynthesis
C) Condensation
D) Transpiration
A) Combustion ✅
What happens during condensation?
A) Rain falling from clouds
B) Water freezing
C) Water vapor → liquid, forming clouds
D) Liquid water → vapor
C) Water vapor → liquid, forming clouds ✅
What percentage of energy is passed on at each trophic level?
A) 25%
B) 50%
C) 5%
D) 10%
D) 10% ✅
How are producers and consumers different?
A) Producers make food, consumers eat food
B) Producers eat food, consumers make food
C) Producers recycle energy, consumers recycle matter
D) Producers and consumers are the same
A) Producers make food, consumers eat food ✅
Can an organism belong to more than one food chain?
A) Only producers can
B) Only decomposers can
C) Yes, because food webs are interconnected
D) No
C) Yes, because food webs are interconnected ✅
How are the carbon and oxygen cycles connected?
A) They are separate
B) They both add nitrogen to the soil
C) They only occur in oceans
D) Plants use CO₂ and release O₂; animals use O₂ and release CO₂
D) Plants use CO₂ and release O₂; animals use O₂ and release CO₂ ✅
Why is nitrogen important?
A) Builds proteins in living things
B) Creates oxygen
C) Cleans water
D) Makes sunlight
A) Builds proteins in living things ✅
What does an energy pyramid show?
A) Nutrients in each ecosystem
B) Population sizes at each level
C) Energy available at each level
D) The number of predators
C) Energy available at each level ✅
What do detritivores and decomposers do?
A) Eat only meat
B) Compete for energy
C) Break down dead matter and recycle nutrients
D) Store energy for plants
C) Break down dead matter and recycle nutrients ✅
Why do scientists prefer food webs to food chains?
A) They look nicer
B) They exclude decomposers
C) They focus only on carnivores
D) They show multiple energy pathways
D) They show multiple energy pathways ✅
Why is carbon called the “building block of life”?
A) All living things are made of it
B) It is rare in nature
C) It stores sunlight
D) It creates water
A) All living things are made of it ✅
What is nitrogen fixation?
A) Turning oxygen into CO₂
B) Storing carbon underground
C) Changing N₂ into usable compounds
D) Breaking down proteins
C) Changing N₂ into usable compounds ✅