Basic Ecological Relationships: Chains, Webs and Pyramids

Ultimately, all of the energy in most food chains or food webs comes from
1. the oceans
2. the producers
3. the sun
4. the carnivores
Organisms that obtain energy directly from photosynthesis are known as
1. autotrophs
2. heterotrophs
3. primary consumers
4. herbivores
Organisms that can feed on autotrophs as well as on heterotrophs are known as
1. primary consumers
2. carnivores
3. herbivores
4. omnivores
5. producers
An organism that feeds only on heterotrophs is a(n)
1. primary consumer
2. carnivore
3. omnivore
4. herbivore
5. autotroph
An organism whose removal from an ecosystem may cause the collapse of that ecosystem is known as a(n)
1. keystone species
2. dominant predator
3. herbivore
4. tertiary consumer
Missing from this food chain are
1. heterotrophs
2. producers
3. consumers
4. carnivores
Wastes and dead organisms from this food chain will be fed upon by
1. autotrophs
2. decomposers
3. herbivores
4. tertiary consumers
Of the organisms depicted above, the one that would likely be found in the smallest number within the ecosystem is the
1. freshwater shrimp
2. bleak
3. perch
4. northern pike
5. osprey
According to the 10% rule, compared to the osprey, the perch has
1. 10x more energy available
2. 100x more energy available
3. 20x more energy available
4. 1/10 the energy available
5. 1/100 the energy available
Food webs differ from food chains in that they
1. show the actual movement of energy within the ecosystem
2. show the distribution of biomass within an ecosystem
3. show more of the available feeding relationships in an ecosystem
4. identify the keystone species within an ecosystem
The producer in this food web is the
1. phytoplankton
2. polar bear
3. capelin
4. herbiverous zooplankton
The most efficient transfer of energy to the artic cod occurs when it feeds on
1. herbivorous zooplankton
2. carnivorous zooplankton
3. harbour seals
4. harp seals
Missing from this food web are
1. primary consumers
2. carnivores
3. producers
4. decomposers
Which of the following has only ONE food source depicted in this web?
1. polar bear
2. harp seal
3. artic char
4. ringed seal
5. killer whale
In a healthy ecosystem, trophic level "A" will be composed of
1. producers
2. heterotrophs
3. autotrophs
4. carnivores
5. herbivores
On the African savanna, large herbivores such as elephant and giraffe would be found in
1. Trophic level A
2. Trophic level B
3. Trophic level C
4. Trophic level D
Based on the diagram, the greatest amount of energy (and biomass) in a healthy ecosystem will be found in the
1. producers
2. primary consumers
3. secondary consumers
4. tertiary consumers
There is about 100x more energy stored in trophic level A than in
1. trophic level B
2. trophic level C
3. trophic level D
4. trophic levels B, C and D combined
Assume that a human can choose from any of the three organisms above as a source of nutrition. Which of the food sources provides the most efficient transfer of energy from the sun to us?
1. Eat the corn!
2. Eat the steer!
3. Eat the wolf!
The food chain above shows
1. one producer, one autotroph, and one decomposer
2. one autotroph and two heterotrophs
3. one heterotroph and two autotrophs
4. one producer and two omnivores