Punnett Square interactive worksheet - Free Printable

Let's solve each of the "Your Turn Now!" Punnett square problems step by step, based on the information provided in the image.

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🔹 Problem 1: Eye Color (Father: BB, Mother: bb)

Given:
- Father has dominant brown eyes (BB)
- Mother has recessive blue eyes (bb)

We need to find the possible eye colors of their child.

#### Step 1: Set up the Punnett square
- Father’s alleles: B and B → go on the top
- Mother’s alleles: b and b → go on the side

```
B B
-----------
b | Bb Bb
-----------
b | Bb Bb
```

#### Result:
All offspring are Bb (heterozygous)

Since B (brown) is dominant over b (blue), all children will have brown eyes.

✔ Answer: All children will have brown eyes.

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🔹 Problem 2: Hair Type (Father: Cc, Mother: cc)

Given:
- Father has curly hair (Cc) → curly is dominant
- Mother has straight hair (cc) → straight is recessive

We need to find the possible hair features of the child.

#### Step 1: Set up the Punnett square
- Father’s alleles: C and c → top
- Mother’s alleles: c and c → side

```
C c
-----------
c | Cc cc
-----------
c | Cc cc
```

#### Result:
- 50% Cc → curly hair (C is dominant)
- 50% cc → straight hair

✔ Answer: The child has a 50% chance of curly hair and a 50% chance of straight hair.

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🔹 Problem 3: Flower Petal Color (RR × Rr)

Given:
- Red petal = dominant (RR)
- Yellow petal = hybrid (Rr) — this means one dominant (R), one recessive (r)
- Cross: RR × Rr

We need to determine the offspring.

#### Step 1: Set up the Punnett square
- Parent 1 (RR): R and R → top
- Parent 2 (Rr): R and r → side

```
R R
-----------
R | RR RR
-----------
r | Rr Rr
```

#### Result:
- 50% RR → red petals
- 50% Rr → red petals (since R is dominant)

So all offspring will have red petals, but half are homozygous (RR), half heterozygous (Rr).

✔ Answer: All offspring will have red petals. Genotypes: 50% RR, 50% Rr.

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🔹 Problem 4: Seed Pod Shape (SS × ss)

Given:
- Smooth seed pod = SS (dominant)
- Wrinkled seed pod = ss (recessive)
- Cross: SS × ss

#### Step 1: Set up the Punnett square
- Parent 1 (SS): S and S → top
- Parent 2 (ss): s and s → side

```
S S
-----------
s | Ss Ss
-----------
s | Ss Ss
```

#### Result:
All offspring are Ss → smooth seed pods (since S is dominant)

✔ Answer: All offspring will have smooth seed pods.

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✔ Summary of Answers:

| Problem | Parents | Offspring Genotypes | Phenotype |
|--------|--------|---------------------|-----------|
| 1 | BB × bb | All Bb | All brown eyes |
| 2 | Cc × cc | 50% Cc, 50% cc | 50% curly, 50% straight hair |
| 3 | RR × Rr | 50% RR, 50% Rr | All red petals |
| 4 | SS × ss | All Ss | All smooth seed pods |

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📌 Final Notes:

- Dominant alleles (capital letters) mask recessive alleles (lowercase).
- A hybrid genotype (e.g., Rr, Cc) means one dominant and one recessive allele.
- In all cases, the phenotype depends on whether at least one dominant allele is present.

Let me know if you'd like these drawn out visually or explained further!