Activity 2: For You To Do
Teaching Suggestions and Sample Answers
Part A: A Food Chain
1. a) A green plant is eaten by a grasshopper, which is eaten by a frog,
which is eaten by a snake, which is eaten by a hawk.
b) and c) green plant–grasshopper–frog–snake–hawk.
d) The producer is the green plant.
e) The consumers are the grasshopper, frog, snake, and hawk.
f) The grasshopper is a herbivore.
g) The frog, snake, and hawk are carnivores.
h) The decomposers are missing from the food chain.
Part B: A Food Web
1. Provide each student with a name tag and an organism card. See Blackline Master Ecology 2.2: Organism Cards. Alternatively, you may wish students to generate their own organism cards. If time permits, you may wish to develop organism cards that include pictures of the organism.
3. Yarn also works well in this activity.
4. a) The string will begin to form a web.
5. a) There will be slight “loosening” of the web.
b) Ask the students to focus on what happens to the other organisms in the circle. Pay attention to the organisms that will now not be eaten as well as those that were going to eat the eliminated organism. Ask students to also consider
if eliminating an organism affects organisms that are not directly linked.
Students should note that eliminating one organism affects all the organisms
in a food web. However, in a food web with a large number of organisms,
there are alternative pathways possible.
6. You may wish to demonstrate this type of food web by using, for example,
a tundra food web. Producers could include flowering plants, grasses, sedges, willows, and lichens. First-order consumers could include musk ox and lemmings. Second-order consumers could include snowy owls and Arctic fox, both of which feed on lemmings.
a) The web could completely collapse if an organism is removed.
b) The greater the biodiversity of an ecosystem, the less the impact of removing one organism.
|