Define synapsis.

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Synapsis**: Synapsis is defined as the pairing of homologous chromosomes during the zygotene phase of prophase I in meiosis.

2. **Understanding Homologous Chromosomes**: Homologous chromosomes are pairs of chromosomes that are similar in size, shape, and genetic content. Each pair consists of one chromosome from each parent.

3. **Location in the Cell Cycle**: Synapsis occurs specifically during the zygotene stage, which is the second subphase of prophase I in meiosis.

...