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8th grade · Science · Unit 6 of 9

Genes & Heredity

Genes, mutations and reproduction.

What your child practices

Practices how genes on chromosomes code for proteins that shape traits, how mutations can be harmful, helpful or neutral, and how sexual and asexual reproduction differ in passing on genes.

Arizona Academic Standards learning standard: 8.L3U1.9; 8.L3U3.10 · genetic variation in offspring, and technology in genetic research

How we explain it

Children can open this short lesson before they practice.

  1. Genes are pieces of DNA on chromosomes. They code for proteins that shape traits.
  2. A dominant allele shows its trait when present; a recessive one shows only if there are two.
  3. Mutations change DNA and can be harmful, helpful or neutral.

Example: B (brown) is dominant over b. Which color is an animal that is Bb? One dominant allele is enough to show. B is brown. Answer: brown

Genes & Heredity in Arizona

In the Arizona Academic Standards, this is unit 6 of 9 in 8th grade Science, after Light & Radiation and before Natural Selection.

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: Arizona Department of Education

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

    Different forms of a gene are called…

    • alleles
    • cells
    • chromosomes
    • proteins

  2. Question 2

    Genes carry instructions for making…

    • proteins
    • rocks
    • water
    • sunlight

  3. Question 3

    Humans get how many chromosomes from each parent?

    • 46
    • 23
    • 2
    • 100

  4. Question 4

    Asexual reproduction produces offspring that are…

    • always sterile
    • genetically identical to the parent
    • a mix of two parents
    • very different from the parent

  5. Question 5

    A mutation is…

    • a change in DNA
    • a type of food
    • a new cell wall
    • a kind of rock

  6. Question 6

    Why might a mutation in a body cell NOT be passed to offspring?

    • Only mutations in sex cells are inherited
    • Body cells have no DNA
    • Mutations always disappear
    • Offspring have no genes

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