Cell Cycle of an ordinary animal cell -

Options

A. `2noverset(" Mitosis ")tonoverset(" Fertilization ")to2noverset(" Meiosis ")to2n`
B. `noverset(" Meiosis ")to2noverset(" Fertilization ")to2noverset(" Mitosis ")ton`
C. `2noverset(" Meiosis ")tonoverset(" Fertilization ")to2noverset(" Mitosis ")to2n`
D. `2noverset(" Fertilization ")to(n)overset(" Mitosis ")to2noverset(" Meiosis ")ton`

Answer

### Step-by-Step Solution for the Cell Cycle of an Ordinary Animal Cell

1. **Understanding the Cell Type**:
- An ordinary animal cell is typically a diploid cell, which means it contains two sets of chromosomes. This is represented as 2n, where "n" is the number of chromosomes in a single set.

2. **Meiosis for Gamete Formation**:
- In the process of gamete formation, the diploid cell undergoes meiosis. Meiosis is a type of cell division that reduces the chromosome number by half, resulting in haploid cells (n). These haploid cells are the gametes (sperm and egg).

3. **Fertilization**:
- When a male gamete (sperm) and a female gamete (egg) fuse during fertilization, they form a zygote. The zygote is diploid (2n) because it contains one set of chromosomes from each parent.

4. **Mitosis for Growth**:
- After fertilization, the zygote undergoes mitosis to divide and multiply. Mitosis is a type of cell division that maintains the chromosome number, meaning the zygote remains diploid (2n) as it divides and grows into an organism.

5. **Identifying the Correct Option**:
- Now, we need to analyze the options given in the question:
- **Option 1**: 2n mitosis and fertilization - Incorrect, as mitosis does not reduce chromosome numbers.
- **Option 2**: 2n meiosis - Incorrect, as meiosis reduces the number of chromosomes.
- **Option 3**: 2n meiosis n fertilization 2n mitosis 2n - Correct, as it accurately describes the process.
- **Option 4**: 2n fertilization n - Incorrect, as fertilization results in a diploid zygote, not haploid.

6. **Conclusion**:
- The correct answer is **Option 3**: 2n meiosis n fertilization 2n mitosis 2n.