Worksheet featuring dihybrid cross problems with Punnett squares, genetic information, and probability questions for plant height and flower color, and guinea pig fur color and texture.

Problem Analysis and Solution Explanation

The provided worksheet involves dihybrid crosses, which are genetic crosses involving two traits. We will solve the problems step by step, using Punnett squares to determine probabilities and genotypes.

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#### Question 1: Setting up a Punnett Square
- Traits:
- Height: Dominant allele for tall plants = D, Recessive allele for dwarf plants = d
- Flower color: Dominant allele for purple flowers = W, Recessive allele for white flowers = w
- Cross: Homozygous dominant parent (DDWW) with a homozygous recessive parent (ddww)

##### Punnett Square Construction
The gametes from the parents are:
- Parent 1 (DDWW): Produces gametes DW
- Parent 2 (ddww): Produces gametes dw

The Punnett square is set up as follows:

| | DW | DW | DW | DW |
|-----|----|----|----|----|
| dw | DdWw | DdWw | DdWw | DdWw |
| dw | DdWw | DdWw | DdWw | DdWw |
| dw | DdWw | DdWw | DdWw | DdWw |
| dw | DdWw | DdWw | DdWw | DdWw |

All offspring have the genotype DdWw.

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#### Question 2: Probability Calculations Using the Punnett Square
We use the Punnett square from Question 1 to answer the probability questions.

##### a. Probability of producing tall plants with purple flowers
- Genotype(s): All offspring have the genotype DdWw.
- Phenotype: Tall (dominant D) and Purple (dominant W).
- Probability: 100% (all offspring are tall and have purple flowers).

##### b. Probability of producing dwarf plants with white flowers
- Genotype(s): Dwarf plants require the genotype dd, and white flowers require the genotype ww.
- Possible genotype(s): None of the offspring have the genotype ddww.
- Probability: 0%.

##### c. Probability of producing tall plants with white flowers
- Genotype(s): Tall plants require the genotype D_, and white flowers require the genotype ww.
- Possible genotype(s): None of the offspring have the genotype D_ww.
- Probability: 0%.

##### d. Probability of producing dwarf plants with purple flowers
- Genotype(s): Dwarf plants require the genotype dd, and purple flowers require the genotype W_.
- Possible genotype(s): None of the offspring have the genotype ddW_.
- Probability: 0%.

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#### Question 3: Setting up a Punnett Square
- Traits:
- Fur color in guinea pigs: Dominant allele for black fur = B, Recessive allele for white fur = b
- Fur texture: Dominant allele for rough fur = R, Recessive allele for smooth fur = r
- Cross: Heterozygous parent (BbRr) with a heterozygous parent (BbRr)

##### Punnett Square Construction
The gametes from the parents are:
- Parent 1 (BbRr): Produces gametes BR, Br, bR, br
- Parent 2 (BbRr): Produces gametes BR, Br, bR, br

The Punnett square is set up as follows:

| | BR | Br | bR | br |
|-----|----|----|----|----|
| BR | BBRR | BBRr | BbRR | BbRr |
| Br | BBRr | BBrr | BbRr | Bbrr |
| bR | BbRR | BbRr | bbRR | bbRr |
| br | BbRr | Bbrr | bbRr | bbr |

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#### Question 4: Probability Calculations Using the Punnett Square
We use the Punnett square from Question 3 to answer the probability questions.

##### a. Probability of producing guinea pigs with black, rough fur
- Genotype(s): Black fur requires the genotype B_, and rough fur requires the genotype R_.
- Possible genotype(s): BBRR, BBRr, BbRR, BbRr
- Count: 9 out of 16
- Probability: 9/16

##### b. Probability of producing guinea pigs with black, smooth fur
- Genotype(s): Black fur requires the genotype B_, and smooth fur requires the genotype rr.
- Possible genotype(s): BBrr, Bbrr
- Count: 3 out of 16
- Probability: 3/16

##### c. Probability of producing guinea pigs with white, rough fur
- Genotype(s): White fur requires the genotype bb, and rough fur requires the genotype R_.
- Possible genotype(s): bbRR, bbRr
- Count: 3 out of 16
- Probability: 3/16

##### d. Probability of producing guinea pigs with white, smooth fur
- Genotype(s): White fur requires the genotype bb, and smooth fur requires the genotype rr.
- Possible genotype(s): bbr
- Count: 1 out of 16
- Probability: 1/16

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Final Answers

1. Punnett Square for Question 1: All offspring have the genotype DdWw.
2. Probabilities for Question 2:
- a. 100%
- b. 0%
- c. 0%
- d. 0%
3. Punnett Square for Question 3: Shown above.
4. Probabilities for Question 4:
- a. 9/16
- b. 3/16
- c. 3/16
- d. 1/16

Final Answer:
\[
\boxed{100\%, 0\%, 0\%, 0\%, \frac{9}{16}, \frac{3}{16}, \frac{3}{16}, \frac{1}{16}}
\]