Which process creates new combinations of genes on chromosomes?

The correct answer is genetic recombination, which is a crucial process that occurs during meiosis, the type of cell division that produces gametes (sperm and eggs). During this process, homologous chromosomes pair up and exchange segments of their genetic material through a mechanism known as crossing over. This exchange results in chromosomes that contain new combinations of alleles, leading to increased genetic diversity in offspring.

Genetic recombination is significant because it mixes the genetic contributions of two parents, creating unique gene combinations that can enhance the adaptability and evolution of a population. This process is one of the fundamental mechanisms of inheritance and plays a vital role in natural selection and evolution.

Other processes, such as gene expression, chromosomal duplication, and allele separation, do not involve the creation of new combinations of genes on chromosomes. Gene expression refers to how genes are turned on or off and used to produce proteins, while chromosomal duplication is simply the replication of chromosomes without altering their genetic composition. Allele separation occurs during meiosis, specifically during anaphase I, where homologous chromosomes are pulled apart, but it does not involve the recombination of genetic material.