Genotype, phenotype and offspring ratios

Grade 7 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Esme's trait card shows a pea plant with flowers at the stem tips (terminal) and the letters aa. Which label is right?

   • Genotype aa; phenotype terminal flowers
   • Genotype terminal flowers; phenotype aa
   • Genotype aa; phenotype axial flowers
   • Genotype Aa; phenotype terminal flowers
2. 2.

   Pea pod shape, I = inflated (dominant), i = constricted (recessive). Gene pair: II; trait: ?. Jun's pea plant has the letters II for pod shape. Which word fits II?

   • Homozygous recessive: two small letters
   • Phenotype: the look of the pods
   • Homozygous dominant: two capital letters
   • Heterozygous: two different letters
3. 3.

   Pea pod shape, I = inflated (dominant), i = constricted (recessive). Gene pair: ii; trait: ?. Kira's pea plant has the letters ii for pod shape. Which word fits ii?

   • Homozygous recessive: two small letters
   • Phenotype: the letters are what you see
   • Homozygous dominant: two capital letters
   • Heterozygous: one of each letter
4. 4.

   Pea flower position, A = axial (dominant), a = terminal (recessive). Gene pair: Aa; trait: ?. Luz's pea plant has the letters Aa for flower position. Which word fits Aa?

   • Phenotype, since the letters show the look
   • Homozygous recessive, as it has an a
   • Homozygous dominant, as it looks axial
   • Heterozygous: two different letters
5. 5.

   Pea pod color, G = green (dominant), g = yellow (recessive). Gene pair: Gg; trait: ?. Milo reads a trait card: a pea plant with the letters Gg. What color are its pods?

   • Yellow, since it carries a g
   • Yellow-green, a mix of both
   • Green, since G is dominant
   • Half green and half yellow pods
6. 6.

   Pea pod shape, I = inflated (dominant), i = constricted (recessive). Gene pair: Ii; trait: ?. Noah reads a trait card: a pea plant with the letters Ii. What shape are its pods?

   • Inflated, since I is dominant
   • Constricted, since it carries an i
   • Partly inflated and partly pinched
   • Constricted, since i is written last
7. 7.

   Pea flower position, A = axial (dominant), a = terminal (recessive). Gene pair: aa; trait: ?. Pia reads a trait card: a pea plant with the letters aa. Where do its flowers grow?

   • Along the stem (axial), as axial is dominant
   • Both along the stem and at the tips
   • Nowhere: aa plants have no flowers
   • At the stem tips (terminal)
8. 8.

   Ren fills a Punnett square for Gg × Gg pea plants. How many of the four boxes are heterozygous (Gg)?

   • 4: each box has a G or g
   • 2: the two Gg boxes
   • 3: each box that has a G
   • 1: just the GG box
9. 9.

   Tala fills a Punnett square for II × Ii pea plants. How many of the four boxes are homozygous (II)?

   • 1: just the top-left box
   • 4: each box looks inflated
   • 2: the two II boxes
   • 0: no box has two of one letter
10. 10.

    Zee fills a Punnett square for Aa × Aa pea plants. How many of the four boxes are homozygous (AA or aa)?

    • 3: the boxes that look axial
    • 1: just the AA box
    • 0: each box has an A
    • 2: the AA box and the aa box