These are bounded opportunities, not learner attainment. Partial and blocked source requirements remain so.

• partial: Understand polar food chains — in the Antarctic, phytoplankton are eaten by krill, krill are eaten by fish and penguins, and penguins are eaten by leopard seals and orcas; in the Arctic, algae under ice feeds zooplankton, which feeds fish, which feeds seals, which feeds polar bears — and that tiny organisms like krill and plankton are the foundation of all polar life

  Bounded objective: Build food chains with arrows from food to eater. Selected links only; canonical all polar life/collapse wording is overbroad and retained only as source, not taught as an absolute.

• partial: Construct an Antarctic food chain: phytoplankton → krill → penguin → leopard seal or orca

  Antarctic chain constructed from feeding links.

• partial: Construct an Arctic food chain: algae → zooplankton → fish → seal → polar bear

  Arctic chain built with supplied sequence facts.

• partial: Explain why krill and plankton are critical — without them, the entire food chain collapses

  Producer/krill loss reasoning qualified by alternative prey, not universal collapse.

• partial: Can {{name}} explain a polar food chain — starting from tiny plankton, through krill and fish, up to seals and polar bears or orcas — and explain why the tiny creatures at the bottom are so important?

  Try offers new-supplied-links-application for the bounded objective; it does not establish every part of the source assessment. Selected links only; canonical all polar life/collapse wording is overbroad and retained only as source, not taught as an absolute.

• Selected links only; canonical all polar life/collapse wording is overbroad and retained only as source, not taught as an absolute.