The fruit fly, Drosophila melanogaster, is widely used to study the genetics of various processes in insects, including immunity. Although the fruit fly immune system has been researched for nearly five decades and a lot has been characterized, there remain as many unanswered questions as those that have been solved. In this dissertation, using fruit flies and tools of genetics, I attempt to further our understanding of some unanswered questions in the field of immunology. There is a growing body of evidence suggesting innate immune systems also possess immune ‘memory’ and can contribute to Trans-Generational Immune Priming (TGIP). Given that the fruit fly is a model system widely used for immunology-related research, it is essential to determine whether this phenomenon is present in this species. I performed experiments examining mortality rates and pathogen loads in offspring of infected parents and contrasted them to those in offspring of control parents. I found no evidence for the presence of TGIP in fruit flies. In the second project of this dissertation, I explored signatures of immune activation and their impact on infection outcomes. I found that infection by some bacterial pathogens was controlled by one or a subset of Anti-Microbial Peptides (AMPs) and that there was significant variation in the kinetics of post infection AMP expression between genotypes. I tested whether quick upregulation of AMPs could lead to favorable infection outcomes, like lower host mortality and lower pathogen loads. However, results did not show any evidence for this hypothesis. In the third, and last, project of this dissertation, I studied the impact of injury on infection progression. Septic infection by the same pathogen inoculated via different tissue led to drastic differences in pathogen load and host survival. I tested whether some sites of inoculation were more amenable for pathogen growth and investigated whether the JNK pathway contributed to this phenomenon. Experiments showed no evidence for this hypothesis.