Define chiasmata.

Explanation

**Step-by-Step Solution:**

1. **Understanding Homologous Chromosomes**:
- Homologous chromosomes are pairs of chromosomes that consist of one chromosome from each parent. They have the same genes at the same loci but may have different alleles.

2. **Pairing of Homologous Chromosomes**:
- During meiosis, homologous chromosomes align closely together in a process called synapsis. This pairing is crucial for genetic recombination.

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