Final answer:
Homologous chromosomes are pairs of chromosomes with the same genes at the same loci, received from each parent. Orthologues are genes in different species with a common ancestry and similar function, while paralogues are related genes in the same organism that have evolved new functions.
Step-by-step explanation:
Homologous chromosomes are a pair of chromosomes in a diploid organism that have the same size, shape, and contain the same genes, although the alleles of these genes may differ. These chromosomes are derived from each parent, meaning that one homologue comes from the mother and the other from the father. The genes found on homologous chromosomes are at the same location, or loci.
During mitosis, which is the process of cell division resulting in two genetically identical daughter cells, the homologous chromosomes are separated into each new cell. Therefore, the outcome from mitosis is the maintenance of the original chromosome number of the parent cell.
When discussing evolutionary biology, we often encounter terms like homologues, orthologues, and paralogues. Orthologues are genes in different species that evolved from a common ancestral gene by speciation. This usually means they retain the same function across species. Paralogues, on the other hand, are genes that are related by duplication within a genome. They evolve new functions, even if they reside within the same organism.