What is crossing over ?

Explanation

### Step-by-Step Text Solution for "What is Crossing Over?"

1. **Definition of Crossing Over**: Crossing over is the process of exchanging genetic material between homologous chromosomes during meiosis. This exchange occurs specifically between non-sister chromatids of homologous chromosomes.

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

3. **Sister and Non-Sister Chromatids**: In a homologous chromosome pair, each chromosome consists of two identical sister chromatids. Non-sister chromatids are the chromatids from different homologous chromosomes.

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