food chains

• What is the unit of measurement for energy in food chains?

  Joules (J)
• What percentage of energy is transferred from one trophic level to the next in a food chain?

  10%
• In the food chain grass → rabbit → fox, how much energy does the fox receive if the grass has 1000 units of energy?

  10 units
• Why are food webs considered more stable than individual food chains?

  Because there are alternative sources of food
• What is the role of grass in the food chain grass → rabbit → fox?

  Producer
• What is the role of the rabbit in the food chain grass → rabbit → fox?

  Primary consumer
• What is the role of the fox in the food chain grass → rabbit → fox?

  Secondary consumer
• What does a pyramid of numbers represent?

  The number of organisms at each trophic level
• Why might a pyramid of numbers be irregular?

  Because there are more parasites than hosts
• What does a pyramid of energy display?

  The energy present at each trophic level
• Why do bottom organisms in a pyramid of energy have more energy?

  Because energy is lost at each trophic level
• What are the main ways energy is lost in a food chain?

  Movement, heat, and undigested materials
• What are the key differences between a pyramid of numbers and a pyramid of energy?

  • Pyramid of numbers: Represents the number of organisms at each trophic level
  • Pyramid of energy: Represents the energy present at each trophic level
  • Pyramid of numbers can be irregular, while pyramid of energy is always upright
• What are the roles of organisms in a typical food chain?

  • Producer: Converts sunlight into energy (e.g., grass)
  • Primary consumer: Eats producers (e.g., rabbit)
  • Secondary consumer: Eats primary consumers (e.g., fox)
  • Tertiary consumer: Eats secondary consumers (e.g., wolf)
• What are the characteristics of a food web?

  • Made up of many interconnecting food chains
  • More stable than individual food chains
  • Provides alternative sources of food
• What are the main reasons for energy loss in a food chain?

  • Movement: Energy used for locomotion
  • Heat: Energy lost as heat during metabolic processes
  • Undigested materials: Energy lost in waste products
• In the food chain grass → grasshopper → rat → owl, what is the role of the grasshopper?

  Primary consumer
• In the food chain grass → grasshopper → rat → owl, what is the role of the rat?

  Secondary consumer
• In the food chain grass → grasshopper → rat → owl, what is the role of the owl?

  Tertiary consumer
• Why is the pyramid of energy always upright?

  Because energy is lost at each trophic level
• What is the significance of the 10% energy transfer rule in food chains?

  It explains why food chains are typically short
• Why might there be more caterpillars than trees in a pyramid of numbers?

  Because one tree can support many caterpillars
• Why might there be fewer rabbits than parasites in a pyramid of numbers?

  Because one rabbit can host many parasites
• What is the main reason for the loss of 90% of energy at each stage in a food chain?

  Energy is used for life processes and lost as heat
• What is the primary source of energy for producers in a food chain?

  Sunlight
• What is the role of decomposers in a food chain?

  They break down dead organisms and recycle nutrients
• Why are herbivores considered primary consumers?

  They eat producers (plants)
• Why are carnivores considered secondary or tertiary consumers?

  They eat other consumers
• What is the significance of the pyramid of energy in understanding ecosystems?

  It shows the flow of energy through different trophic levels
• What is the significance of the pyramid of numbers in understanding ecosystems?

  It shows the number of organisms at each trophic level
• Why is it important to have alternative sources of food in a food web?

  It increases the stability of the ecosystem