Cross between AaBB and aaBB will form

Options

A. 1AaBB : 1aaBB
B. All AaBB
C. 3 AaBB : 1 aaBB
D. 1 AaBB : aaBB

Answer

To solve the problem of the cross between the genotypes AaBB and aaBB, we can follow these steps:

### Step 1: Identify the Gametes
- For the first parent (AaBB), the possible gametes are:
- AB (from A and B)
- aB (from a and B)

- For the second parent (aaBB), the possible gamete is:
- aB (from a and B)

### Step 2: Set Up the Punnett Square
- We will create a Punnett square to visualize the cross. The gametes from the first parent (AaBB) will be placed on one side, and the gametes from the second parent (aaBB) will be placed on the other side.

```
aB
__________
| AB | aB |
|_________|_______|
| AaBb | aaBb |
|_________|_______|
```

### Step 3: Fill in the Punnett Square
- Now we will fill in the Punnett square with the combinations of the gametes:
- The first row combines AB with aB to give AaBb.
- The second row combines aB with aB to give aaBb.

### Step 4: Analyze the Results
- From the Punnett square, we can see the following genotypes of the offspring:
- 1 AaBb
- 1 aaBb

### Step 5: Determine the Ratio
- The resulting genotypes are:
- 1 AaBb
- 1 aaBb
- Therefore, the ratio of the offspring is 1:1.

### Final Answer
The cross between AaBB and aaBB will form offspring in a ratio of 1:1.

---