Food Chains and Webs: Which roles do plants and animals play in their environment?

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As junior scientists, we have investigated the role that plants and animals play in their environment through creating mini-ecosystems in terrariums. To start, we experimented to see how soil contains important nutrients left behind by decomposers like worms for plant growth. Then, we looked at how plants use energy from the sun to produce/make food through photosynthesis. Furthermore, we have observed how primary consumers like crickets eat plants, and secondary consumers like anoles eat the primary consumers. Decomposers like worms eat all the dead organic (once living) matter to break it down into soil.

Sun gives energy to plants and soil provides plants with nutrients. In the soil type experiment, we saw that regular soil holds more water and contains more nutrients than sand, and therefore helps plants grow better. With the light energy and nutrients from soil, plants (producers) produce food through photosynthesis, using a green substance (thing) called chlorophyll. Without light, a plant cannot produce food, as we saw in the light experiment. It will lose its green color because the chlorophyll dies, and the plant turns yellow and eventually dies too.

Cricket life cyle

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This is a diagram of photosynthesis, the process through which plants produce food and oxygen.

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The plant is then eaten by a primary consumer (such as a cricket), which is then eaten by a secondary consumer (such as an anole), which is then eaten by a tertiary consumer (such as an owl). When everything dies, it is decomposed into the soil by decomposers such as worms, mushrooms, and bacteria. Here is an example of a food chain.



Primary Consumer

Secondary Consumer

Tertiary Consumer

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Here is a different example of a food chain:

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Living things have many adaptations (special things that help them survive). For example, anoles can camouflage to protect themselves from predators. Owls have adaptations that make them better predators (hunters), such as sonar hearing to detect high frequency sound that small mammals make, even deep under snow.

Below is a video of an owl, hunting its prey.

A food web is a system of food chains that depend on each other. For example, the plants are eaten by the grasshopper, but also the rabbit and the deer. The grasshopper is eaten by the mouse, but also by the bird. Human beings do not just eat one thing, but many things.

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Below is a video illustrating the different food chains to which krill belong in the ocean. When one part of the food chain is broken, that affects other parts. One year the population of krill decreased near Alaska because the plankton they ate decreased. In turn, this caused a decrease in the salmon that depended on the krill for food.

An ecosystem is made up of the plants and animals that depend on each other to survive in an environment. Disruptions to an ecosystem can hurt organisms within the ecosystem. For example, in our terrariums, if the grass dies, the crickets have nothing to eat. If the crickets die, that means that the anole will have nothing to eat.

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An adaptation is something an organism (plant or animal) has or does that helps it survive.

For example, the thick-billed murre, which live on steep Irish cliffs, lay pear-shaped eggs that don't roll off as easily as oval eggs because the pear-shaped eggs are heavier on the bottom than the top.

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Videos showing examples of adaptations:

1. A tarantula has weak vision, but know when there is prey around because it feels vibrations in its hairs.

2. One important adaptation many lizards have to survive is camouflage.


1. Endangered Tamarin Monkeys in Brazilian Rainforest

2.Brain Pop video on Food Chains.

3. Video on monkeys in cities: Monkey Trouble in India

4. Cartoon video on ecosystems: Resident Weevil

5. Webpage on photosynthesis

6. Food chain video from nature

7. Owl Pellet Bone Chart

8. Another video of an owl hunting using its special hearing

9. Food Chains and Webs Unit Summary

10. Video of Venus Fly Trap

11. Video of Owl Hunting Vole Beneath the Snow

12. Food Chains Glossary

13. Video: Mole Cricket

14. Video: Tarantula Hunting a Cricket

15. Videos on Ecosystems

16. Video on Food Chains in a Pond

17. America's Crayfish in Troubled Waters

18. BBC Video on Speed of a Falcon

19. Leopard Gecko Eating Hornworm

20. Long-Tailed Grass Lizard Catches Crickets

21. Hornworm Life Cycle Video