Biology · KS3 Y9 · Ecosystems

Bioaccumulation

BioaccumulationFree5:56Heddy Score 3 of 7, below the standard
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What you need to know

  • DDT persisted in food chains and harmed birds of prey.
  • A toxin causes this when the body cannot break it down or excrete it.
  • Each consumer eats many organisms from the level below, so the toxin becomes more concentrated towards the top.
  • Mercury in aquatic food chains shows the same pattern.

In this clip

Runs 5:56, from 0:08 to 6:04 of the full video.

Heddy Score3/7, Below the standard
See the seven stars
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

1.06M views · 5.9K likes · Amoeba Sisters 2.98M subscribers

As reported by YouTube on 2026-11-03. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

The DDT story shows why a persistent toxin ends up highest in the top predators.

Amoeba Sisters on YouTubechecked 2026-10-20

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