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9th grade · Science · Unit 15 of 28

DNA, Proteins & Traits

How DNA codes for proteins, and how traits pass from parents to offspring.

What your child practices

Practices how the order of bases in DNA codes for the order of amino acids in proteins, how cells build carbon-based molecules from sugars and elements like nitrogen, how chromosomes carry genes from parents to offspring, and using Punnett squares and probability to predict how traits are spread in offspring and populations.

New York State Learning Standards learning standard: HS-LS1-1; HS-LS1-6; HS-LS3-1; HS-LS3-3 · how DNA codes for proteins, how cells build carbon-based molecules, how chromosomes pass on traits, and the probability of inherited traits

How we explain it

Children can open this short lesson before they practice.

  1. DNA is a double helix. Its base order codes for the amino acids in proteins.
  2. Cells build molecules from sugars plus elements like nitrogen.
  3. Chromosomes pass genes from parents. A Punnett square predicts offspring: Bb × Bb gives 1/4 bb.

Example: Two Bb parents have offspring. What fraction are expected to be Bb? The boxes are BB, Bb, Bb, bb. Two of the four are Bb. Answer: 1/2

DNA, Proteins & Traits in New York

In the New York State Learning Standards, this is unit 15 of 28 in 9th grade Science, after Body Systems & Homeostasis and before Populations & Evolution.

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: New York State Education Department (NYSED)

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

    The order of bases in a gene determines…

    • how much water the cell holds
    • the order of amino acids in a protein
    • the size of the cell wall
    • the color of the DNA

  2. Question 2

    An organism with two different alleles for a trait, like Bb, is…

    • heterozygous
    • a clone
    • homozygous
    • a mutation

  3. Question 3

    The shape of a DNA molecule is a…

    • cube
    • double helix
    • single straight line
    • flat circle

  4. Question 4

    Carbon-based molecules made by living things include…

    • carbohydrates, lipids, proteins and nucleic acids
    • only water
    • only oxygen gas
    • salt, water, sand and iron

  5. Question 5

    Chromosomes are made of…

    • fat and sugar
    • cell walls
    • DNA wound around proteins
    • only water

  6. Question 6

    A mutation changes one base in a gene. The protein it codes for may…

    • turn into a sugar
    • become a chromosome
    • always stay exactly the same
    • get a different amino acid and work differently

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