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7th grade Predict traits with a Punnett square worksheet

6 printable versionsBuilding Confidence10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

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Predict traits with a Punnett square

Grade 7 Science Worksheet - Building Confidence

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Circle the best answer.

  1. Ari fills in a Punnett square for flower color. Which letters go in the blank box?

    • Vv: one letter of each kind
    • vv: two small letters
    • v: a single small letter
    • VV: two capital letters
  2. Esme fills in a Punnett square for seed texture. Which letters go in the blank box?

    • RR: two capital letters
    • rr: two small letters
    • Rr: one letter of each kind
    • R: a single capital letter from the top row
  3. V = violet (dominant), v = white (recessive). Plant: Vv. Jun reads a trait card: a pea plant with the letters Vv. Which flower color does it show?

    • Violet, because V is dominant
    • White, because it has a white letter
    • Pale violet, a mix of the two
    • Half violet and half white flowers
  4. T = tall (dominant), t = dwarf (recessive). Plant: tt. Kira reads a trait card: a pea plant with the letters tt. How tall is it?

    • Tall, because tall is the dominant form
    • Tall, because one t letter is enough to make it tall
    • Dwarf, because it has two recessive letters
    • Medium height, between tall and dwarf
  5. R = round (dominant), r = wrinkled (recessive). Seeds: Rr. Luz reads a trait card: pea seeds with the letters Rr. What texture are the seeds?

    • Round, because R is dominant
    • Wrinkled, because it has an r
    • Half round and half wrinkled
    • Wrinkled, because r is written last
  6. Homozygous, heterozygous, genotype, phenotype. Example plant: Vv. Milo reads that a Vv plant is heterozygous for flower color. What does heterozygous mean?

    • It shows the recessive trait
    • It has two different forms of the gene
    • It has no form of the gene for flower color
    • It has two copies of the same form
  7. Homozygous, heterozygous, genotype, phenotype. Example plant: Vv with violet flowers. Noah reads the word phenotype on a gene word card. What does it mean?

    • The trait you can see, such as violet flowers
    • The dominant letter of the pair
    • The pair of letters for a gene
    • A blend of the two parents’ traits, such as pale violet
  8. Dominant, recessive, genotype, blended. Pia reads about a form of a trait that is hidden when a dominant form is present. What is it called?

    • Recessive
    • Dominant
    • Blended
    • Genotype
  9. Ren reads a filled Punnett square for flower color. How many of the four boxes show white flowers?

    • 0: white skips this cross
    • 1: only the vv box
    • 3: every box with a small v
    • 2: half the boxes
  10. Tala reads a filled Punnett square for plant height. How many of the four boxes show tall plants?

    • 2: the two Tt boxes
    • 0: no box has TT
    • 3: as in most crosses
    • 4: tall is the dominant form
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7th grade Predict traits with a Punnett square worksheet – printable
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About this worksheet

Predict traits with a Punnett square. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can fill a Punnett square for one gene with two forms and read which trait each box shows.
  • I can give the chance of a trait as a percent, and the expected number out of many offspring.
  • I can work backward from offspring to parents, use a test cross, and explain why real counts land near, not on, the square's ratio.

Standard: MS-LS3-2

Words to know

gene, allele: A gene is an instruction for a trait; alleles are its forms (V or v)

dominant: The form that shows when at least one copy is there (capital letter)

recessive: The form that shows only with two copies (two small letters)

genotype / phenotype: The letter pair / the trait you can see

homozygous / heterozygous: Two same letters (VV, vv) / two different letters (Vv)

Punnett square: A grid that shows every way the parents' letters can pair up

test cross: Crossing an unknown plant with a vv plant to find its letters

Common mistakes

Your child filled a Punnett box with both letters from one parent. Each box takes one letter from the top and one from the side. Try covering the other boxes and reading across and down together.

Your child thought a plant with one dominant and one recessive letter (such as Vv) shows the recessive trait. With a dominant letter present, the dominant trait shows. Ask your child what the capital letter means.

Your child expected the two traits to mix into an in-between, such as pale violet or medium height. For Mendel’s pea traits the forms do not blend: each plant shows one trait or the other. Ask your child which form a Vv plant shows.

Questions parents ask

What is the most common mistake with predict traits with a punnett square?

Your child filled a Punnett box with both letters from one parent. Each box takes one letter from the top and one from the side. Try covering the other boxes and reading across and down together.

Are these 7th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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