Food chains

• What is the main focus of today's video?

  Energy passing through an ecosystem
• What does a food chain illustrate?

  What gets eaten by what in an ecosystem
• How does a food chain differ from a food web?

  A food chain shows one interaction chain
• What is the starting point of all food chains?

  A producer, like a green plant
• What does "photosynthetic" mean?

  Organisms produce glucose using sunlight
• What is biomass in the context of plants?

  Biological molecules incorporated into plants
• Who are the primary consumers in a food chain?

  Organisms that eat producers
• What is the role of secondary consumers?

  They feed on primary consumers
• What does "tertiary" refer to in a food chain?

  Third level of consumers
• What happens to energy as it moves up the food chain?

  Most energy gets lost at each level
• If there are 1,000 joules in grass, how much energy reaches mice?

  About 100 joules
• How much energy might an owl receive from the food chain?

  About 20 joules
• What do the arrows in a food chain represent?

  The flow of energy up the chain
• What is a predator-prey cycle?

  Population variations of predators and prey
• How do predator and prey populations interact over time?

  They cycle up and down together
• What does it mean when predator populations lag behind prey populations?

  Predator population peaks after prey population
• What happens when the owl population is low?

  The mouse population increases significantly
• What occurs when there are many mice available?

  The owl population starts to increase
• What happens when the owl population becomes too high?

  The mouse population declines due to predation
• Why do populations cycle rather than reach equilibrium?

  It takes time for populations to change
• What is the main takeaway from the video on food chains?

  Understanding energy flow and predator-prey cycles