|Most higher organisms reproduce sexually and they produce offspring through the union of reproductive cells from two different parents. Eg: Violets produce showy flowers that attract insects that carry pollen from one plant to the next. Offspring resulting from this cross-pollination are genetically distinct from either parent. Violets also produce flowers that never open, and are self-pollinated. The resulting offspring are genetically similar, though not identical, to the parent. And violets send out creeping stems. Plants sprouting from these runners are genetically identical to the parent plant.
Genetic differentiation within species occurs as a result of sexual reproduction, in which genetic differences between individuals are combined in their offspring to produce new combinations of genes in the DNA. Genetic diversity is usually mentioned agriculture and maintaining food security.
Review article comes in the form of systematic reviews and literature reviews and are a form of secondary literature. Systematic reviews determine an objective list of criteria, and find all previously published original research papers that meet the criteria. They then compare the results presented in these papers. Literature reviews, by contrast, provide a summary of what the authors believe are the best and most relevant prior publications.