Video summary

CER (Claim, Evidence, Reasoning) in Biology

Main summary

Key takeaways

Educational

Main ideas and concepts / lessons

  • Shift from feeling “not good at” to focusing on your strengths

    • The speaker notes they aren’t skilled at activities like cooking, organizing, and crafts.
    • They emphasize a growth mindset: skill can improve with practice over time.
    • Their real strength is being curious, which they present as foundational for scientific thinking.

  • Curiosity leads to scientific questions

    • The speaker grew up near a pond in Texas with semi-aquatic turtles, mostly red-eared sliders.
    • In winter, the turtles seemed to “disappear,” leading to questions such as:
      • Where do they go?
      • Do they migrate?
      • Do they hibernate? If so, where?
    • This curiosity becomes the motivation for a potential scientific investigation.

  • Science inquiry is not necessarily linear

    • The video references a Nature of Science idea: science often isn’t one straight, universal process like a single “scientific method.”

  • Introduce a cross-curricular explanation framework: CER

    • The framework is CER = Claim, Evidence, Reasoning.
    • It’s mainly presented as a way to construct scientific explanations, especially a reliable conclusion after an investigation.
    • CER does not have to follow a strict order during writing, but it must include these components.

Methodology / step-by-step structure

How to use CER for a conclusion/explanation

  • Claim

    • State the answer to the original question/problem.

  • Evidence

    • Provide data that supports the claim, such as:
      • Observations (qualitative data can work, depending on the investigation)
      • Research findings from credible sources (ideally peer-reviewed)

  • Reasoning

    • Explain how/why the evidence supports the claim.
    • Connect evidence to scientific concepts (e.g., terminology and mechanisms).

Example CER application using the turtle scenario

  • Original question (driving claim)

    • When the pond surface freezes over, where do the red-eared sliders go to survive?

  • Proposed evidence collection (investigation content)

    • Observational/qualitative data

      • Set up cameras to monitor the pond/turtles
      • Observe before winter and after winter
      • Ensure turtles are not disturbed
      • Note whether turtles remain in the water or leave it
      • Observe inactivity when the surface freezes

    • Research data

      • Look up science journal papers on freshwater turtle winter survival
      • Check source credibility (avoid unreliable sources like personal blogs or neighbor anecdotes)
      • Identify the term and mechanism: brumation (for ectotherms like turtles)

  • Claim (example conclusion statement)

    • In the winter when the pond surface freezes over, red-eared sliders from this pond remain in the water and brumate.

  • Evidence (what supports the claim)

    • Observations showing:

      • Turtles remain in the water during freezing
      • The same turtles are present after winter ends
      • Turtles show inactivity during freezing conditions

    • Peer-reviewed research that:

      • Defines inactivity as brumation
      • Explains how turtles can brumate in the water during winter freeze conditions

  • Reasoning (how/why the evidence supports the claim)

    • Observed survival and continued presence in-water suggest they did not leave or migrate away permanently.
    • The inactivity matches brumation, and physiological explanations from cited research support that survival can occur even when the surface freezes.

Key biological concept explained

  • Brumation
    • Similar to hibernation in mammals (metabolic slowdown), but specifically for ectotherms (like red-eared sliders).
    • During brumation:
      • Turtles can handle low oxygen environments
      • Their metabolic needs slow down
      • Physiological changes occur that allow survival through winter conditions

Broader takeaway

  • CER can be applied beyond biology
    • When encountering claims in daily life, ask:
      • Is there evidence?
      • Is there reasoning that connects the evidence to the claim?

Speakers / sources featured

  • Speakers

    • The Amoeba Sisters (narrator/presenter; no individual name is given in the subtitles)

  • Sources referenced

    • Peer-reviewed science journal papers about freshwater turtle winter survival and red-eared slider brumation

  • Named concept comparisons

    • Mammalian hibernation (as a comparison to brumation)

Original video