Food chains and predator-prey cycles

• What should you be able to do by the end of this video?

  Use food chains to represent feeding relationships
• How do the numbers of predators and prey change over time?

  They change in cycles
• What biotic factor affects organisms mentioned in the video?

  A source of food
• What do scientists call the first organism in a food chain?

  Producer
• What is the role of producers in food chains?

  They synthesize complex molecules
• What molecule do green plants make through photosynthesis?

  Glucose
• What is biomass in the context of food chains?

  Complex molecules passed down the food chain
• Who are the primary consumers in the food chains discussed?

  Rabbits and caterpillars
• What do we call animals that eat primary consumers?

  Secondary consumers
• In the food chain with four stages, who is the tertiary consumer?

  Bird of prey
• What is a predator?

  An animal that kills and eats others
• In the first food chain, who is the prey?

  Rabbit
• What happens to the populations of predator and prey over time?

  They rise and fall in cycles
• What might cause changes in predator-prey cycles?

  A drought or a new predator
• What are the key components of a food chain?

  • Producers (e.g., green plants)
  • Primary consumers (e.g., rabbits, caterpillars)
  • Secondary consumers (e.g., small birds)
  • Tertiary consumers (e.g., birds of prey)
  • Predators and prey relationships
• Describe the predator-prey population cycle.

  1. Rabbit population increases due to food availability.
  2. Fox population increases as more rabbits are available.
  3. Rabbit population decreases due to increased predation.
  4. Fox population decreases due to fewer rabbits.
  5. Rabbit population increases again, restarting the cycle.