Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant? How is the constancy maintained in these three stages?

Explanation

### Step-by-Step Solution:

1. **Understanding the Chromosome Number**:
- The chromosome number refers to the total number of chromosomes present in a cell. In sexually reproducing organisms, this number is constant for a species and is typically represented as 2n (diploid), which means two sets of chromosomes.

2. **Formation of the Zygote**:
- A zygote is formed when a sperm cell fertilizes an egg cell. This fertilization restores the diploid chromosome number, which is characteristic of that particular organism.

...