👉 In the context of biology and genetics, a homologous chromosome is a chromosomal segment that contains identical or similar DNA sequences. In other words, two homologous chromosomes are copies of each other with identical sequences within them. For example, in humans, there are three homologous chromosomes: chromosome 1 (also known as the X chromosome), chromosome 2, and chromosome 3. These three chromosomes have identical sequences because they contain identical DNA molecules that have been duplicated many times over