Zygote in sexually reproducing organisms

Options

A. is a vital link ensuring continuity of species from one generation to the other
B. it undergoes mitosis in organisms with haplontic life cycle to form embryo
C. it is the first cell of gametophytic phase
D. it is the last cell of sporophytic phase

Answer

### Step-by-Step Solution:

1. **Understanding the Zygote**:
- A zygote is the initial cell formed when two gametes (sperm and egg) fuse during fertilization in sexually reproducing organisms. It represents the first stage of development for a new organism.

2. **Role of the Zygote**:
- The zygote is crucial for the continuity of a species. It carries genetic material from both parents, which ensures that the offspring have a mix of traits from both the mother and father.

3. **Chromosome Number**:
- In sexually reproducing organisms, gametes are haploid (n), meaning they contain one set of chromosomes. When the male and female gametes fuse, they form a diploid zygote (2n), which contains two sets of chromosomes.

4. **Continuity of Species**:
- The formation of the zygote is essential for the continuation of a species. Since the zygote has the diploid number of chromosomes, it ensures that the genetic information is preserved and passed on to the next generation.

5. **Conclusion**:
- Therefore, the correct answer to the question about the role of the zygote in sexually reproducing organisms is that it is a vital link ensuring continuity of a species from one generation to another.

### Answer:
**Option A: It is a vital link ensuring continuity of species from one generation to another.**

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