A pair of chromosomes that are similar but genetically different is known as homologous chromosomes. Homologous chromosomes are pairs of chromosomes that are similar in size, shape, and genetic content. They are found in diploid organisms, which have two sets of chromosomes in each of their cells. Homologous chromosomes are important because they help ensure that an organism's genetic information is correctly inherited and passed down to its offspring.
During meiosis, the process of cell division that produces gametes (sex cells), homologous chromosomes pair up and exchange genetic material through a process called recombination. This process helps to create genetically diverse offspring, as it allows for the shuffling and mixing of genetic information from both parents. Homologous chromosomes are a key feature of eukaryotic cells and play an important role in the development and function of organisms.