Homologous chromosomes are pairs of chromosomes in a diploid organism that have the same structure and gene sequence. One chromosome of each pair is inherited from the mother, while the other comes from the father. These chromosomes carry genes that control the same traits, but they may have different versions, known as alleles. During meiosis, homologous chromosomes undergo a process called crossing over, where they exchange genetic material. This exchange increases genetic diversity in the resulting gametes. Homologous chromosomes are crucial for proper cell division and play a significant role in inheritance and evolution.