This organelle’s dysfunction can cause NARP, a form of retinitis pigmentosa with neurodegeneration. In 2016, John Zhang controversially performed the first successful “spindle transfer” to circumvent a disease of this organelle, creating the first three-parent baby. “Stroke-like episodes” and lactic acidosis name one multisystem disease of this organelle. A Gomori trichrome stain can diagnose diseases of this organelle like Kearns-Sayre Disease and (*) Leigh (“LEE”) Syndrome through the appearance of characteristic “ragged (10[1])red fibers.” Diseases’ severity and age of onset are most likely to be affected by heteroplasmy when they involve this organelle’s dysfunction, (10[1])as it replicates asexually and (10[1])independently from other organelles. (10[1])For 10 points, name this organelle (10[1])that is passed on by maternal inheritance through its own DNA and performs oxidative phosphorylation to make ATP. ■END■