Define molecular homology.

Explanation

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

1. **Definition of Molecular Homology**: Molecular homology refers to the similarities in the molecular structures of different organisms. It focuses on the genetic, protein, or biochemical similarities that arise from a common evolutionary ancestor.

2. **Understanding Homology**: The term "homology" itself means similarity. In the context of molecular biology, it indicates that certain molecular components are similar across different species.

3. **Molecular Level Similarities**: Molecular homology specifically deals with the similarities observed at the molecular level, such as DNA sequences, RNA sequences, or protein structures.

...