Answer:
The correct answer will be crossing over (genetic recombination) in sexual reproduction.
Step-by-step explanation:
Reproduction in organisms takes place by two ways- sexual and asexual.
Sexual reproduction involves the fusion of two gametes and is bi-parental while asexual reproduction is uni-parental so does not involve fusion of two gametes and produce "clones" which are exact copies of themselves.
The key feature which takes place in sexual reproduction is that gamete formed involve the genetic information from both parents so, offsprings inherit characters of both the parents and after fertilization exchange of genetic material between homologous chromosomes takes place through a process known as "crossing over" which takes place during prophase of meiosis I. This crossing over or genetic recombination results in formation of new combinations of alleles increasing genetic diversity.
Thus, crossing over (genetic recombination) in sexual reproduction is the correct answer.