Download Ecosystems intro worksheet - answers

Intro to Ecosystems
1. Define the following terms:
Species: group of organisms that can interbreed to produce fertile offspring.
Habitat: A place where an organism lives
Population: All the members of the same species within the same habitat
Community: All the different populations within the same habitat
Ecosystem: The community and the habitat together
Ecology: study of relationships between living organisms and their environment
Niche: where, when and how an organism lives
Biodiversity: amount of biological diversity per unit area (species/habitat/genetic)
Trophic level: a feeding stage/level in a food chain
2. Complete the tree below with definitions and examples of each type of feeding strategy.
Distinguish between the feeding strategies at each level of the diagram.
Autotrophy – organisms that produce their OWN food
Photo (light) – photosynthesis - plants/phytoplankton/algae
Heterotrophy – organisms which get energy from other organisms
Consumers – ingest organic matter (killed/recently)
Decomposers – detritivores (ingests non living organic matter) and Saprotrophs – digests non living matter by
enzyme secretion (fungi/bacteria)
3. Food chains represent the flow of energy and nutrients in a series of feeding relationships.
Give one example of a marine food chain (min. 4 organisms)
Phytoplankton
Krill
Cod
Seal
Give one example of a terrestrial food chain (min. 4 organisms)
Iris
Caterpillar
Great tit
Sparrowhawk
Give one other example of a food chain (min. 4 organisms)
Phytoplankton
Shrimp
Bream
Osprey
4. Describe what is meant by a food web.
Food webs show all of the feeding relationships in an ecosystem (all the food chains interlinked)
5. The food web below shows some coral reef feeding relationships;
Identify species in the following trophic levels:
i.
Producers – phytoplankton/algae
ii.
Primary consumers – sea-whip/parrotfish/turtles/marine invertebrates
iii.
Secondary consumers – reef sharks/snappers/groupers
6.
Use the diagram of the marine food web below to answer the following questions.
Which of these best describes the role of the krill in this food web?
A.
B.
C.
D.
decomposer
primary consumer
producer
secondary consumer
Which of these best describes the role of the leopard seal in this food web?
A.
B.
C.
D.
tertiary consumer
primary consumer
producer
decomposer
Which of these best describes the role of the phytoplankton in this food web?
A.
B.
A.
B.
tertiary consumer
primary consumer
producer
secondary consumer
7. Constructing a Food Web
How is energy passed from organism to organism in an ecosystem? A food chain
shows a single path for energy flow in an ecosystem. The overlapping
relationships between food chains are shown in a food web. Food webs can be
very complicated which makes ecological relationships very difficult to trace all
the energy pathways between organisms.
Ecologists have studied a low elevation meadow ecosystem and determined the
dietary habits of several organisms in the community. Use the relationships
below to construct a food web.
Identify the herbivores, carnivores, omnivores, and detritivores (decomposers) in the food web.
Identify whether the organism is an autotroph or a heterotroph.
INFORMATION
 Red foxes feed on raccoons, crayfishes, grasshoppers, red clover, meadow voles, and gray
squirrels.
 Red clover is eaten by grasshoppers, muskrats, red foxes, and meadow voles.
 Meadow voles, gray squirrels, and raccoons all eat parts of the white oak tree.
 Crayfishes feed on green algae and detritus, and they are eaten by muskrats and red foxes.
 Raccoons feed on muskrats, meadow voles, gray squirrels, and white oak trees.
Draw your food web in this space: