Which of these combinations would result in a zygote that would develop into a male child?

Options

A. Egg containing X chromosome and sperm containing Y chromosome
B. Egg containing X chromosome and sperm containing X chromosome
C. Egg containing Y chromosome and sperm containing X chromosome
D. None of above

Answer

To determine which combination would result in a zygote that develops into a male child, we need to understand the role of chromosomes in determining the sex of a child.

### Step-by-Step Solution:

1. **Understanding Chromosomes**:
- Humans have two sex chromosomes: X and Y.
- Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

2. **Identifying the Egg and Sperm Contributions**:
- The egg always contributes an X chromosome.
- The sperm can contribute either an X or a Y chromosome.

3. **Analyzing the Options**:
- **Option 1**: Egg containing X chromosome and sperm containing Y chromosome.
- This combination results in an XY zygote, which will develop into a male child. **(Correct)**
- **Option 2**: Egg containing X chromosome and sperm containing X chromosome.
- This combination results in an XX zygote, which will develop into a female child. **(Incorrect)**
- **Option 3**: Egg containing Y chromosome and sperm containing X chromosome.
- This option is not possible because an egg cannot contain a Y chromosome; it can only contain X. **(Incorrect)**
- **Option 4**: None of the above.
- Since we have identified the first option as correct, this option is also incorrect. **(Incorrect)**

4. **Conclusion**:
- The only combination that results in a zygote developing into a male child is the first option: an egg containing an X chromosome and a sperm containing a Y chromosome.

### Final Answer:
The combination that would result in a zygote that develops into a male child is **an egg containing an X chromosome and a sperm containing a Y chromosome**.

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