CurriculumGrade 9Science

Adaptation

Aligned to HS-LS4-4 — Next Generation Science Standards.

What this lesson teaches

As selection favors helpful inherited traits generation after generation, a population becomes better matched to its environment. This accumulated good fit between organism and environment is called an adaptation.

Worked example

When bacteria are exposed to an antibiotic, the few with resistance genes survive and multiply, so after repeated doses nearly the whole population is resistant, an adaptation to the drug.

Practice questions

  1. Identify an adaptation in an organism and the environment it fits.
  2. Show how repeated selection over generations increases a helpful trait in a population.
  3. Construct an evidence-based explanation for how antibiotic resistance evolves in bacteria.

Watch the lesson

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

▶ Watch this lesson

En español

Adaptación

A medida que la selección favorece los rasgos heredados útiles generación tras generación, una población se ajusta mejor a su ambiente. Este buen ajuste acumulado entre el organismo y el ambiente se llama adaptación.

Ejemplo: Cuando se expone a las bacterias a un antibiótico, las pocas que tienen genes de resistencia sobreviven y se multiplican, así que tras dosis repetidas casi toda la población es resistente: una adaptación al fármaco.

More HS-LS4 Biological Evolution lessons

Four Factors of EvolutionHS-LS4-2Advantageous Traits SpreadHS-LS4-3Environmental Change and SpeciesHS-LS4-5Simulating ConservationHS-LS4-6

Teach this lesson today

An AI tutor that guides with questions instead of just giving answers — all K–12 core subjects, every child in the family.

Start free — no card required