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8th grade · Science · Unit 5 of 7

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.

Alaska content standards learning standard: MS-LS3-1; MS-LS4-5 · genes and mutations, and technologies that influence inheritance

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 Alaska

In the Alaska content standards, this is unit 5 of 7 in 8th grade Science, after Fields & Forces at a Distance 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: Alaska Department of Education and Early Development

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

    Mutations can be…

    • always harmful
    • harmful, helpful or neutral
    • never inherited
    • always helpful

  2. Question 2

    Humans get how many chromosomes from each parent?

    • 100
    • 46
    • 2
    • 23

  3. Question 3

    Genetic engineering means…

    • training it
    • feeding it more
    • changing an organism's genes directly
    • changing its habitat

  4. Question 4

    Genes are found on…

    • mitochondria only
    • ribosomes
    • chromosomes
    • cell walls

  5. Question 5

    Genes are made of…

    • protein only
    • fat
    • DNA
    • sugar

  6. Question 6

    BB × bb: what fraction are expected to show the dominant trait?

    • All of them
    • One-quarter
    • Half
    • None

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