Punnetts Square Activity - Shows Mendels Genetics - Free Printable

Problem Overview:

The task involves using Punnett squares to determine the possible offspring genotypes and phenotypes for different parent combinations in a plant height trait. The alleles are defined as follows:
- T: Dominant allele for tall plants
- t: Recessive allele for short plants

The Punnett squares provided in the image represent four different parent combinations. We need to fill in the Punnett squares and determine the possible offspring for each scenario.

---

Step-by-Step Solution:

#### 1. Both parents are dominant tall (TT × TT)

- Parents: TT (dominant tall) × TT (dominant tall)
- Punnett Square:
```
T T
T TT TT
T TT TT
```
- Offspring Genotypes: All offspring will have the genotype TT.
- Phenotypes: All offspring will be tall (phenotype tall).

Answers:
1. TT (tall)
2. TT (tall)
3. TT (tall)
4. TT (tall)

---

#### 2. Both parents are mixed hybrids (Tt × Tt)

- Parents: Tt (mixed hybrid) × Tt (mixed hybrid)
- Punnett Square:
```
T t
T TT Tt
t Tt tt
```
- Offspring Genotypes: TT, Tt, Tt, tt
- Phenotypes:
- TT: Tall (dominant tall)
- Tt: Tall (mixed hybrid)
- tt: Short (recessive short)
- Ratio of Tall to Short:
- Tall (TT + Tt): 3 out of 4
- Short (tt): 1 out of 4

Answers:
1. TT (tall)
2. Tt (tall)
3. Tt (tall)
4. tt (short)

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#### 3. One parent is dominant tall (TT) and one is a mixed hybrid (Tt)

- Parents: TT (dominant tall) × Tt (mixed hybrid)
- Punnett Square:
```
T t
T TT Tt
T TT Tt
```
- Offspring Genotypes: TT, TT, Tt, Tt
- Phenotypes: All offspring will be tall (either TT or Tt).
- Ratio of Tall to Short:
- Tall (TT + Tt): 4 out of 4
- Short (tt): 0 out of 4

Answers:
1. TT (tall)
2. TT (tall)
3. Tt (tall)
4. Tt (tall)

---

#### 4. Both parents are recessive short (tt × tt)

- Parents: tt (recessive short) × tt (recessive short)
- Punnett Square:
```
t t
t tt tt
t tt tt
```
- Offspring Genotypes: All offspring will have the genotype tt.
- Phenotypes: All offspring will be short (phenotype short).

Answers:
1. tt (short)
2. tt (short)
3. tt (short)
4. tt (short)

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Final Answers:

1. Both parents are dominant tall (TT × TT):
- 1. TT (tall)
- 2. TT (tall)
- 3. TT (tall)
- 4. TT (tall)

2. Both parents are mixed hybrids (Tt × Tt):
- 1. TT (tall)
- 2. Tt (tall)
- 3. Tt (tall)
- 4. tt (short)

3. One parent is dominant tall (TT) and one is a mixed hybrid (Tt):
- 1. TT (tall)
- 2. TT (tall)
- 3. Tt (tall)
- 4. Tt (tall)

4. Both parents are recessive short (tt × tt):
- 1. tt (short)
- 2. tt (short)
- 3. tt (short)
- 4. tt (short)

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Boxed Final Answer:

\[
\boxed{
\begin{array}{l}
\text{1. TT (tall), TT (tall), TT (tall), TT (tall)} \\
\text{2. TT (tall), Tt (tall), Tt (tall), tt (short)} \\
\text{3. TT (tall), TT (tall), Tt (tall), Tt (tall)} \\
\text{4. tt (short), tt (short), tt (short), tt (short)}
\end{array}
}
\]