Genotype, phenotype and offspring ratios
Grade 7 Science Worksheet - Building Confidence

Circle the best answer.
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
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
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
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
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
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
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)
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
Tala fills a Punnett square for II × Ii pea plants. How many of the four boxes are homozygous (II)?
Punnett square for pea pod shape (I = inflated (dominant), i = constricted (recessive)). Top parent II (letters I and I across the top); side parent Ii (letters I and i down the side). Boxes: top-left II; top-right II; bottom-left Ii; bottom-right Ii. Beside it, gene pair | trait: II | inflated pods; Ii | inflated pods. Punnett square for pea pod shape (I = inflated (dominant), i = constricted (recessive)). Top parent II (letters I and I across the top); side parent Ii (letters I and i down the side). Boxes: top-left II; top-right II; bottom-left Ii; bottom-right Ii. Beside it, gene pair | trait: II | inflated pods; Ii | inflated pods. pea pod shape (I = inflated (dominant), i = constricted (recessive)) I I I II II i Ii Ii gene pair | trait gene pair trait II inflated pods Ii inflated pods - 1: just the top-left box
- 4: each box looks inflated
- 2: the two II boxes
- 0: no box has two of one letter
Zee fills a Punnett square for Aa × Aa pea plants. How many of the four boxes are homozygous (AA or aa)?
Punnett square for pea flower position (A = axial (dominant), a = terminal (recessive)). Top parent Aa (letters A and a across the top); side parent Aa (letters A and a down the side). Boxes: top-left AA; top-right Aa; bottom-left Aa; bottom-right aa. Beside it, gene pair | trait: AA | axial flowers; Aa | axial flowers; aa | terminal flowers. Punnett square for pea flower position (A = axial (dominant), a = terminal (recessive)). Top parent Aa (letters A and a across the top); side parent Aa (letters A and a down the side). Boxes: top-left AA; top-right Aa; bottom-left Aa; bottom-right aa. Beside it, gene pair | trait: AA | axial flowers; Aa | axial flowers; aa | terminal flowers. Punnett square for pea flower position Aa times Aa A a A AA Aa a Aa aa gene pair | trait gene pair trait AA axial flowers Aa axial flowers aa terminal flowers A = axial (dominant), a = terminal (recessive). Top parent Aa. Side parent 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

