Predict traits with a Punnett square

Grade 7 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

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

   • v: a single small letter
   • VV: two capital letters
   • Vv: one letter of each kind
   • vv: two small letters
2. 2.

   Esme fills in a Punnett square for seed texture. Which letters go in the blank box?

   • R: a single capital letter from the top row
   • rr: two small letters
   • Rr: one letter of each kind
   • RR: two capital letters
3. 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?

   • Half violet and half white flowers
   • White, because it has a white letter
   • Violet, because V is dominant
   • Pale violet, a mix of the two
4. 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?

   • Dwarf, because it has two recessive letters
   • Tall, because tall is the dominant form
   • Tall, because one t letter is enough to make it tall
   • Medium height, between tall and dwarf
5. 5.

   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 no form of the gene for flower color
   • It has two different forms of the gene
   • It has two copies of the same form
6. 6.

   Homozygous, heterozygous, genotype, phenotype. Example plant: Vv with violet flowers. Noah reads the word phenotype on a gene word card. What does it mean?

   • A blend of the two parents’ traits, such as pale violet
   • The pair of letters for a gene
   • The dominant letter of the pair
   • The trait you can see, such as violet flowers
7. 7.

   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
   • Blended
   • Dominant
   • Genotype
8. 8.

   Ren reads a filled Punnett square for flower color. How many of the four boxes show white flowers?

   • 2: half the boxes
   • 0: white skips this cross
   • 1: only the vv box
   • 3: every box with a small v
9. 9.

   Tala reads a filled Punnett square for plant height. How many of the four boxes show tall plants?

   • 3: as in most crosses
   • 4: tall is the dominant form
   • 2: the two Tt boxes
   • 0: no box has TT
10. 10.

    Zee reads a filled Punnett square for seed texture. How many of the four boxes show round seeds?

    • 3: the RR box and both Rr boxes
    • 4: round is the dominant form
    • 2: the two Rr boxes
    • 1: just the RR box