Food Chains & Webs

10SCIE - Ecology

Finn LeSueur

2020

Akoranga 2 Mahi Tuatahi

  1. Write the date in your book
  2. Think about your breakfast this morning, what did you eat? Write it down.
  3. Where did what you ate, get its energy? What about the organism before that?

Ngā Whāinga Ako

  1. Put a series of organisms into a food chain and explain the flow of energy
  2. Classify living things as producers, herbivores, carnivores, omnivores or decomposers

Write ngā whāinga ako in your book

Food Chains / Raupapa Kame

  • We can give the energy relationship between many organisms as a food chain
  • Each step in the chain is called a trophic level
  • Energy flows from the bottom to the top
Source

Interpreting Food Chains

Source
  • The first organism on a chain is a producer who creates their own energy (usually through photosynthesis)
  • Recall: photosynthesis is the process of creating sugar and energy from sunlight!

Primary Consumers / Kaikame

  • Primary consumers gain their energy by eating producers
  • They are typically herbivores
    • Herbivores gain their energy by eating only plant matter
Source

Secondary.. Consumers

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  • Secondary and onwards consumers are typically omnivores or carnivores
  • Omnivores gain energy by eating both plant and animal matter
  • Carnivores gain energy by eating only animal matter

Why does the pyramid get smaller?

  • At each trophic level, not all energy is transferred to the next level
  • Energy is lost through heat to the surroundings
  • Energy is lost through decomposition via decomposers, to be used by producers!
Source

Ngohe: Ted-Ed

  1. Open Google Classroom and find the task on Feedback Loops
  2. Watch the video attached
  3. Answer the questions in the Think, Dig Deeper and Discuss sections

https://ed.ted.com/on/2h7WUzCk

Pātai: Food Chain Effects

Source
  • Humans go fishing and catch too many fish, and reduce the population by 75%.
  • What are the impacts of this on the food chain? Discuss with the person next to you and write in your book.

Whakatika

  • The decrease in fish population means that sharks will have less to eat. This means some sharks may not get enough food, and die. This will cause a decrease in their population.
  • A decrease in fish population means that barnacles will have fewer predators and be eaten less. This means their population will increase.
  • An increase in the population of barnacles will mean more phytoplankton are being eaten, perhaps causing a decrease in the phytoplankton population.

Ngohe: Clusters

  1. Cut out the different organisms
  2. Group them into their different categories
  3. Glue them into your book in clusters

Akoranga 3 Mahi Tuatahi

  1. Write the date in your book
  2. Cut up the mix and match squares
  3. Match and stick them into your book

Te Whāinga Ako

  1. Define a community and how it relates to both living things and the area that they live in

Write te whāinga ako in your book

Competition / Whakataetae

  • At each trophic level, organisms compete with other (same and different species) for various resources.
    • Food
    • Water
    • Mates
    • Light
    • Space
Source

Food Webs / Māwhaiwhai Kame

  • A food web is multiple interlinking food chains
  • It displays the energy flow between multiple different food chains
  • They better represent the real world than food chains
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Flow-On Effects

  • Changing the population of one trophic level can have a more complex impact on the food chain
  • E.g. An increase in heron could lead to a decrease in eel.
  • Pātai: In pairs, discuss and explain why this is true in your book.
Source

Pātai

  • Discuss and explain in your exercise book, the flow on effects that were to happen if a disease were to kill a large percentage of the zooplankton in the estuary.
  • What would happen if both the zooplankton and flounder died off due to a disease?
Source

Ngohe: Food Web Activity on Classroom

  • Open Google Classroom and find the Food Web Activity
  • Complete the two tasks on the document.

Mahi Kāinga: EP

  • Education Perfect Task on:
    1. Producers
    2. Impact of Humans on New Zealand Wildlife

When doing Education Perfect tasks, always take your time and makes notes on any new information in your exercise book!

Akoranga 4 Mahi Tuatahi

  1. Open the Food Web Activity on Google Classroom
  2. Complete the activity in the next 10 minutes and Hand In
  3. Open the Pond Organisms Tūhura/Investigation document