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8th grade · Science · Unit 8 of 13

Natural Selection

Variation, survival and populations changing over time.

What your child practices

Practices how variation in traits leads some individuals to survive and reproduce more, how populations change over generations, and how artificial selection works.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 8.13(C) · how trait variation leads to adaptations that affect survival

How we explain it

Children can open this short lesson before they practice.

  1. Individuals vary. Those with helpful traits survive and reproduce more.
  2. Over generations, helpful traits become more common: natural selection.
  3. In artificial selection, people choose which plants or animals breed, like dog breeds.

Example: Farmers breed only the cows that give the most milk. What is this? People, not nature, are choosing. Choosing by people is artificial selection. Answer: artificial selection

Natural Selection in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 8 of 13 in 8th grade Science, after Genes & Heredity and before Water, Acids & Bases.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Individuals with helpful traits are more likely to…

    • survive and reproduce
    • die young
    • stop reproducing
    • change their DNA on purpose

  2. Question 2

    Which is an inherited trait natural selection could act on?

    • A scar from a fight
    • Fur thickness
    • A learned trick
    • A broken leg

  3. Question 3

    Natural selection requires…

    • variation in traits
    • identical individuals
    • unlimited food
    • no reproduction

  4. Question 4

    Finches with different beaks on different islands show…

    • same diets
    • adaptation to different foods
    • random paint
    • no variation

  5. Question 5

    Which is NOT needed for natural selection?

    • Organisms choosing their traits
    • Competition
    • Inheritance
    • Variation

  6. Question 6

    Why does finishing antibiotics as prescribed matter?

    • Bacteria need it to grow
    • Stopping early can leave resistant bacteria to multiply
    • It has no effect
    • It makes bacteria stronger always

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