Completed Punnett Square Practice Worksheet showing answers for genetics problems involving dominance, recessiveness, and inheritance patterns.

Let's go through the Punnett Square Practice Worksheet step by step and evaluate the answers, correct any mistakes, and explain the reasoning.

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Question 1: Determine Phenotypes

> Purple flowers are dominant to white flowers.
- PP → Purple ✔
- Pp → Purple ✔
- pp → White ✔

> Hairy knuckles are dominant to non-hairy knuckles in humans.
- HH → Hairy ✔
- Hh → Hairy ✔
- hh → Non-hairy ✔

> Bobtails in cats are recessive. Normal tails are dominant.
- TT → Normal ✔
- Tt → Normal ✔
- tt → Bobtail ✔

✔ All answers for Question 1 are correct.

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Question 2: Genotype Classification

Determine if each genotype is:
- Homozygous dominant (AA)
- Heterozygous (Aa)
- Homozygous recessive (aa)

| Genotype | Answer Given | Correct? | Explanation |
|---------|--------------|----------|------------|
| AA | Homozygous dominant | ✔ | Two identical dominant alleles |
| gg | Homozygous recessive | ✔ | Two identical recessive alleles |
| Pp | Heterozygous | ✔ | One dominant, one recessive allele |
| Ii | Heterozygous | ✔ | Same as above |
| tt | Homozygous recessive | ✔ | Two recessive alleles |
| TT | Homozygous dominant | ✔ | Two dominant alleles |

✔ All answers for Question 2 are correct.

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Questions 3–5: Dog Fur Color Genetics

> Gene for fur color in dogs:
- Dominant allele (F) = Grey fur
- Recessive allele (f) = Black fur

#### Scenario:
- Female dog is heterozygous → Ff
- Male dog is homozygous recessive → ff

We need to use a Punnett square to determine:
- Possible genotypes of puppies
- Percentages of genotypes and phenotypes

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Step 1: Set up the Punnett Square

Place male alleles (ff) on top, female alleles (Ff) on the side:

```
f f
---------------
F | Ff | Ff
---------------
f | ff | ff
---------------
```

So the possible offspring genotypes are:
- Ff → 2 out of 4 → 50%
- ff → 2 out of 4 → 50%

There is no FF because the male contributes only 'f' alleles.

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Genotype Percentages:

- FF: 0% ✔
- Ff: 50% ✔
- ff: 50% ✔

✔ These are correct.

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Phenotype Percentages:

- Grey fur: Requires at least one F → Ff → 50% ✔
- Black fur: Only ff → 50% ✔

✔ These are also correct.

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Punnett Square Diagram (Corrected)

The student’s diagram has a small error:

They wrote:
```
f f
------
F | Ff Ff
------
f | ff ff
```

But they labeled the squares incorrectly:
- The top row should be labeled with male gametes: f and f
- The left column with female gametes: F and f
- Then the squares should be:
- Top-left: Ff → Grey
- Top-right: Ff → Grey
- Bottom-left: ff → Black
- Bottom-right: ff → Black

However, the student labeled the bottom two boxes as "FF", which is incorrect.

✘ Mistake: They wrote FF instead of Ff and ff.

It looks like they may have mixed up the alleles.

Let’s fix it:

✔ Corrected Punnett Square:

```
f f
-----------------
F | Ff (grey) | Ff (grey)
-----------------
f | ff (black) | ff (black)
-----------------
```

So:
- Ff → grey fur
- ff → black fur

The phenotypic ratio is 50% grey, 50% black.

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✔ Final Answers Summary:

#### Question 3:
- % of possible Genotypes:
- FF: 0%
- Ff: 50%
- ff: 50%
- % of possible Phenotypes:
- Black fur: 50%
- Grey fur: 50%

✔ All percentages are correct.

✘ But the Punnett square labeling is incorrect — the student wrote FF in the boxes where it should be Ff or ff.

---

✔ Final Correction:

Correct Punnett Square:

| | f | f |
|-------|-------|-------|
| F | Ff → grey | Ff → grey |
| f | ff → black | ff → black |

This shows:
- 2/4 = 50% Ff → grey fur
- 2/4 = 50% ff → black fur

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🟩 Conclusion:

- All answers for questions 1 and 2 are correct.
- Question 3 answers (percentages) are correct.
- ✘ The Punnett square has an error in labeling — FF was written instead of Ff and ff.
- ✔ The final percentages are correct, but the diagram needs correction.

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🔧 Recommended Fix:

Replace the labels in the Punnett square:
- Top-left: Ff → grey
- Top-right: Ff → grey
- Bottom-left: ff → black
- Bottom-right: ff → black

And label the rows/columns properly:
- Rows: F and f (from female)
- Columns: f and f (from male)

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✔ Final Answer:
- Genotypes: 0% FF, 50% Ff, 50% ff
- Phenotypes: 50% grey fur, 50% black fur
- Punnett Square corrected as above.

Let me know if you'd like a visual version!