Question

6. In Andalusian fowls, black individuals (B) and white individuals (b) are homozygous. A homozygous black bird is crossed with a homozygous white bird. All offspring are bluish-grey. Show the cross and the genotypic and phenotypic ratios of the offspring.

7. A farmer is breeding chickens and notices an interesting pattern in their feather color. When he breeds a pure white-feathered chicken (WW) with a pure black-feathered chicken (BB), all of the offspring have black and white speckled feathers.

Create a Punnett square to predict the feather colors of the offspring if two black-and-white speckled chickens (BW) are bred together. What is the genotypic and phenotypic ratio?

What inheritance pattern is shown? EXPLAIN

Answer 1

### 6. Cross of Andalusian Fowls

In the given scenario, black (B) and white (b) are the alleles for feather color in Andalusian fowls. The black individuals are homozygous (BB), and the white individuals are homozygous (bb). The cross is as follows:

**Cross:**
- Parent 1: Homozygous Black (BB)
- Parent 2: Homozygous White (bb)

When these two are crossed, all offspring (F1 generation) will have the genotype Bb (heterozygous) and will express the bluish-grey phenotype.

**Punnett Square:**
```
B B
--------------
b | Bb | Bb |
--------------
b | Bb | Bb |
--------------
```

**Genotypic Ratio:**
- Bb : 100% (4 Bb)

**Phenotypic Ratio:**
- Bluish-grey : 100% (4 bluish-grey)

### 7. Punnett Square for Black-and-White Speckled Chickens

In this scenario, we are dealing with two black-and-white speckled chickens (BW), where B represents the black allele and W represents the white allele. When two BW individuals are bred, we can set up a Punnett square to determine the genotypes and phenotypes of the offspring.

**Punnett Square:**
```
B W
----------------
B | BB | BW |
----------------
W | BW | WW |
----------------
```

**Offspring Genotypes:**
- BB: 1
- BW: 2
- WW: 1

**Genotypic Ratio:**
- BB : 1
- BW : 2
- WW : 1
- Ratio: 1 : 2 : 1

**Offspring Phenotypes:**
- Black-feathered (BB): 1
- Black-and-white speckled (BW): 2
- White-feathered (WW): 1

**Phenotypic Ratio:**
- Black : 1
- Speckled : 2
- White : 1
- Ratio: 1 : 2 : 1

### Inheritance Pattern

The inheritance pattern displayed in this chicken breeding example is known as **codominance**. In codominance, both alleles in a heterozygous individual contribute to the phenotype, resulting in a distinct expression that is not a mix or blend of the two traits. In this case, the presence of both black (B) and white (W) alleles results in speckled feathers (BW) in the heterozygous condition (BW). Neither allele is recessive, and both traits are fully expressed in the phenotype.

Answer 2

Can you make the explanation shorter and make it seem like a 9th grader wrote it?

Answer 3

### 6. Andalusian Fowls

In Andalusian fowls, we have two feather colors: black (B) and white (b). Black birds are BB (homozygous), and white birds are bb (homozygous).

**Cross:**
- Parent 1: BB (Black)
- Parent 2: bb (White)

When we cross a black bird with a white bird, all the babies are Bb, which are bluish-grey.

**Punnett Square:**
```
B B
--------------
b | Bb | Bb |
--------------
b | Bb | Bb |
--------------
```

**Genotypic Ratio:**
- 100% Bb

**Phenotypic Ratio:**
- 100% Bluish-grey

---

### 7. Chicken Feather Colors

For the chickens, a pure white chicken (WW) crossed with a pure black chicken (BB) makes all black-and-white speckled chicks (BW).

Now, let’s see what happens when two speckled chickens (BW) are bred together.

**Punnett Square:**
```
B W
----------------
B | BB | BW |
----------------
W | BW | WW |
----------------
```

**Genotypes of Offspring:**
- BB: 1
- BW: 2
- WW: 1

**Genotypic Ratio:**
- 1 BB : 2 BW : 1 WW

**Phenotypic Ratio:**
- Black (BB): 1
- Speckled (BW): 2
- White (WW): 1

---

### Inheritance Pattern

This is an example of **codominance**. In codominance, both alleles show up in the offspring. So, in the case of BW, both black and white colors appear together as speckles.