Question

1. in garden peas, tall (t) vine is dominant over short (t) vine. yellow (y) seed color is dominant over green (y) seed color. cross a heterozygous tall, yellow seeded plant with a heterozygous tall, yellow seeded plant.

genotypes of the parent plants

genotypes | phenotypes
--- | ---

what is the probability for a tall offspring?
what is the probability for a short offspring?
what is the probability for a yellow offspring?
what is the probability for a green offspring?
what is the probability for a tall yellow offspring?
what is the probability for a tall green offspring?
what is the probability for a short yellow offspring?

Explanation:

Step1: Identify parent genotypes

Heterozygous tall, yellow plants have genotype $TtYy$ (both parents).

Step2: List gamete combinations

Each parent produces 4 gametes: $TY, Ty, tY, ty$.

Step3: Complete Punnett Square

$$\begin{array}{c|cccc} & TY & Ty & tY & ty \\ \hline TY & TTYY & TTYy & TtYY & TtYy \\ Ty & TTYy & TTyy & TtYy & Ttyy \\ tY & TtYY & TtYy & ttYY & ttYy \\ ty & TtYy & Ttyy & ttYy & ttyy \\ \end{array}$$

Step4: Count genotype/phenotype totals

Total offspring combinations: 16

• Tall ($T\_$): 12 (all except $ttYY, ttYy, ttYy, ttyy$)
• Short ($tt$): 4
• Yellow ($Y\_$): 12 (all except $TTyy, Ttyy, Ttyy, ttyy$)
• Green ($yy$): 4
• Tall yellow ($T\_Y\_$): 9
• Tall green ($T\_yy$): 3
• Short yellow ($ttY\_$): 3

Step5: Calculate probabilities

Probability = $\frac{\text{Number of desired outcomes}}{\text{Total outcomes}}$

Answer:

Genotypes of the parent plants:

$TtYy$ and $TtYy$

Genotypes and Phenotypes:

Genotypes	Phenotypes
$TTyy, Ttyy$	Tall, green
$ttYY, ttYy$	Short, yellow
$ttyy$	Short, green

Probabilities:

1. Probability for a tall offspring: $\frac{12}{16} = \frac{3}{4}$
2. Probability for a short offspring: $\frac{4}{16} = \frac{1}{4}$
3. Probability for a yellow offspring: $\frac{12}{16} = \frac{3}{4}$
4. Probability for a green offspring: $\frac{4}{16} = \frac{1}{4}$
5. Probability for a tall yellow offspring: $\frac{9}{16}$
6. Probability for a tall green offspring: $\frac{3}{16}$
7. Probability for a short yellow offspring: $\frac{3}{16}$