Punnett Square Worksheet 2 PDF

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Punnett Square Worksheet (One-Factor Crosses) Complete the following one-factor crosses: Identify the dominant and recessive alleles; give the genotypes of the parents; construct and work a Punnett Square; give the number and probability of each genotype and phenotype; give the genotypic and phenotypic ratios for each cross. Be sure to remember that the CAPITAL LETTER is DOMINANT. EXAMPLE PROBLEM A green pea plant (Gg) is crossed with a yellow pea plant (gg). G – GREEN g – YELLOW

Parent 1 – Gg Genotypes Phenotypes Genotypic Ratio = 0:2:2 Parent 2 – gg 0 GG 0% 2 Green 50% Phenotypic Ratio = 2:2 2 Gg 50% 2 Yellow 50% 2 gg 50%

G g g g

Gg Gg

gg gg

1. A tall plant (TT) is crossed with a tall plant (Tt) T - _____ t - _____

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ TT ___ ___ Tall ___ Phenotypic Ratio = _____ ___ Tt ___ ___ Short ___ ___ tt ___

2. A tall plant (Tt) is crossed with a short plant (tt) T - _____ t - _____

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ TT ___ ___ Tall ___ Phenotypic Ratio = _____ ___ Tt ___ ___ Short ___ ___ tt ___

3. A red flower (Rr) is crossed with a white flower (rr) R - _____ r - ______

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ RR ___ ___ Red ___ Phenotypic Ratio = _____ ___ Rr ___ ___ White ___ ___ rr ___

4. A white flower (rr) is crossed with a white flower (rr). Purple is the dominant color. P - _____ p - _____

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ PP ___ ___ Purple ___ Phenotypic Ratio = _____ ___ Pp ___ ___ White ___ ___ pp ___

5. A homozygous dominant brown mouse is crossed with a heterozygous brown mouse. Tan is the recessive color. B - _____ b - _____

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ BB ___ __ Brown __ Phenotypic Ratio = _____ ___ Bb ___ ___ Tan ___ ___ bb ___

6. Two heterozygous white rabbits are crossed. Brown is the recessive trait W - _____ w - _____

Parent 1 – _____ Parent 2 – _____

Genotypes Phenotypes Genotypic Ratio = _____ ___ WW ___ __ White __ Phenotypic Ratio = _____ ___ Ww ___ __ Brown __ ___ ww ___

Punnett Square Worksheet (Two-Factor Crosses) Complete the following two-factor crosses: Identify the dominant and recessive alleles; give the genotypes of the parents; construct and work a Punnett Square; give the number and probability of each genotype and phenotype; give the genotypic and phenotypic ratios for each cross. Be sure to remember that the CAPITAL LETTER is DOMINANT. EXAMPLE PROBLEM In pea plants, green pod color is dominant over yellow pod color. Tall plant height is dominant over short plant height. A tall green pea plant (homozygous for both traits) is crossed with a short yellow pea plant. G – green g – yellow T – tall t- short Plant 1 – GGTT Plant 2 – ggtt

GGTT = 0

GT

GT

GT

GT

gt

GgTt

GgTt

GgTt

GgTt

gt

GgTt

GgTt

GgTt

GgTt

gt

GgTt

GgTt

GgTt

GgTt

gt

GgTt

GgTt

GgTt

GgTt

GGTt = 0

GgTT = 0

ggTT = 0

GgTt = 16

ggTt = 0

GGtt = 0Ggtt = 0

ggtt = 0

Green/Tall = 16 Green/Short = 0 Yellow/Tall = 0 Yellow/Short = 0 1. A tall green pea plant (homozygous for height, heterozygous for pod color) is crossed with a tall green pea plant (heterozygous for both traits). G – green

g – yellow Plant 1 – _____

GGTT =

GGTt =

Green/Tall =

Green/Short =

t- short

Plant 2 – _____

GgTT = ggTT =

T – tall

GgTt = ggTt =

GGtt =

Ggtt =

ggtt = Yellow/Tall =

Yellow/Short =

2. Two tall green pea plants are crossed. One plant is heterozygous for height and homozygous for pod color, while the other is homozygous for height and heterozygous for pod color. G – green

g – yellow

T – tall

t- short

Plant 1 – _____ Plant 2 – _____

GGTT =

GGTt =

GgTT = ggTT =

Green/Tall =

GgTt = ggTt =

Green/Short =

GGtt =

Ggtt =

ggtt = Yellow/Tall =

Yellow/Short =

3. Two tall, green pea plants (heterozygous for both traits) are crossed. G – green

g – yellow

T – tall

t- short

Plant 1 – _____ Plant 2 – _____

GGTT =

GGTt =

GgTT = ggTT =

Green/Tall =

Green/Short =

GgTt = ggTt =

GGtt =

Ggtt =

ggtt = Yellow/Tall =

Yellow/Short =

4. Red flower color is dominant over white flower color. Tall plant height is dominant over short height. A tall red flowered plant (heterozygous for both traits) is crossed with a short white flowered plant. R – red

r – whiteT – tall

t- short

Plant 1 – _____ Plant 2 – _____

RRTT = RRTt =

RrTT = rrTT =

Red/Tall =

Red/Short =

RrTt = rrTt =

RRtt =

Rrtt =

rrtt = White/Tall =

White/Short =...