Non-Mendelian Genetics Practice interactive worksheet | Live ... - Free Printable

Problem Analysis:

The worksheet focuses on codominance, a type of inheritance where both alleles are expressed in the phenotype when an individual is heterozygous. The problem involves determining genotypes for given phenotypes and performing genetic crosses using Punnett squares.

#### Key Information:
1. Eye Shape in Smiley Faces:
- Starred eyes: Genotype `SS`
- Circular eyes: Genotype `CC`
- Circle with a star (both traits): Genotype `CS` (codominance)

2. Blood Type Inheritance:
- Codominance pattern with alleles `Iᴬ` (A), `Iᴮ` (B), and `i` (O).
- Phenotypes and genotypes are provided in the table.

---

Solution:

#### Part 1: Give the Genotypes for the Pictured Phenotypes
We need to determine the genotypes based on the phenotypes shown in the images.

1. First Smiley Face:
- Phenotype: Circular eyes (`OO`)
- Genotype: `CC` (homozygous for circular eyes)

2. Second Smiley Face:
- Phenotype: Starred eyes (`**`)
- Genotype: `SS` (homozygous for starred eyes)

3. Third Smiley Face:
- Phenotype: Circle with a star (`@*`)
- Genotype: `CS` (heterozygous, showing both traits due to codominance)

Answer for Question 7:
- First Smiley: `CC`
- Second Smiley: `SS`
- Third Smiley: `CS`

---

#### Part 2: Genetic Crosses Using Punnett Squares

##### 8(a): Star-eyed x Circle-eyed
- Parents:
- Star-eyed: Genotype `SS`
- Circle-eyed: Genotype `CC`
- Punnett Square:
```
| C | S
-------------
C | CC | CS
S | CS | SS
```
- Phenotypes of Offspring:
- `CC`: Circular eyes
- `CS`: Circle with a star
- `SS`: Starred eyes

- Genotypes of Offspring:
- `CC`, `CS`, `CS`, `SS`

- Counts:
- Circle-eyed (`CC`): 1
- Circle-star eyed (`CS`): 2
- Star-eyed (`SS`): 1

##### 8(b): Circle-star eyed x Circle-star eyed
- Parents:
- Both Circle-star eyed: Genotype `CS`
- Punnett Square:
```
| C | S
-------------
C | CC | CS
S | CS | SS
```
- Phenotypes of Offspring:
- `CC`: Circular eyes
- `CS`: Circle with a star
- `SS`: Starred eyes

- Genotypes of Offspring:
- `CC`, `CS`, `CS`, `SS`

- Counts:
- Circle-eyed (`CC`): 1
- Circle-star eyed (`CS`): 2
- Star-eyed (`SS`): 1

---

#### Part 3: Blood Type Inheritance
This section provides information about blood types and their inheritance patterns but does not require solving any specific problems. It serves as background knowledge.

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Final Answers:

1. Question 7:
- First Smiley: `CC`
- Second Smiley: `SS`
- Third Smiley: `CS`

2. Question 8(a):
- Phenotypes of offspring: `CC`, `CS`, `CS`, `SS`
- How many are circle-eyed? 1
- How many are circle-star eyed? 2
- How many are star-eyed? 1

3. Question 8(b):
- Phenotypes of offspring: `CC`, `CS`, `CS`, `SS`
- How many are circle-eyed? 1
- How many are circle-star eyed? 2
- How many are star-eyed? 1

---

Boxed Final Answer:

\[
\boxed{
\text{7. } CC, SS, CS \\
\text{8(a). } \text{Phenotypes: } CC, CS, CS, SS; \text{ Counts: } 1, 2, 1 \\
\text{8(b). } \text{Phenotypes: } CC, CS, CS, SS; \text{ Counts: } 1, 2, 1
}
\]