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?

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

   Bo fills in a Punnett square for plant height. Which letters go in the blank box?

   • TT: two capital letters, both taken from the top
   • T: a single capital letter
   • tt: two small letters
   • Tt: one letter of each kind
3. 3.

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

   • RR: two capital letters
   • Rr: one letter of each kind
   • R: a single capital letter from the top row
   • rr: two small letters
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
   • Medium height, between tall and dwarf
   • Tall, because tall is the dominant form
   • Tall, because one t letter is enough to make it tall
5. 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 r is written last
   • Wrinkled, because it has an r
   • Half round and half wrinkled
6. 6.

   Homozygous, heterozygous, genotype, phenotype. Example plant: Vv. Milo reads that a Vv plant is heterozygous for flower color. What does heterozygous mean?

   • It has two copies of the same form
   • It has two different forms of the gene
   • It has no form of the gene for flower color
   • It shows the recessive trait
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?

   • Genotype
   • Dominant
   • Blended
   • Recessive
8. 8.

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

   • 0: white skips this cross
   • 2: half the boxes
   • 3: every box with a small v
   • 1: only the vv box
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
   • 2: the two Tt boxes
   • 0: no box has TT
   • 4: tall is the dominant form
10. 10.

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

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