Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[EX Q]: It is generally accepted that the mitochondria play central roles in energy production of most eukaryotes. In contrast, it has been thought that Plasmodium spp., the causative agent of malaria, rely mainly on cytosolic glycolysis but not mitochondrial oxidative phosphorylation for energy production during blood stages. However, Plasmodium spp. possesses all genes necessary for the tricarboxylic acid (TCA) cycle and most of the genes for electron transport chain (ETC) enzymes. Therefore, it remains elusive whether oxidative phosphorylation is essential for the parasite survival. To elucidate the role of TCA metabolism and ETC in malaria parasites, we deleted the gene for flavoprotein (Fp) subunit, Pbsdha, one of four components of complex II, a catalytic subunit for succinate dehydrogenase activity. The Pbsdha(-) parasite grew normally at blood stages in mouse. In contrast, ookinete formation of Pbsdha(-) parasites in the mosquito stage was severely impaired. Finally, Pbsdha(-) ookinetes failed in oocyst formation, leading to complete malaria transmission blockade. These results suggest that malaria parasite may switch the energy metabolism from glycolysis to oxidative phosphorylation to adapt to the insect vector where glucose is not readily available for ATP production.
[EX A]: Which is the causative agent of malaria?

[EX Q]: Sandford-on-Thames is a village and Parish Council beside the River Thames in Oxfordshire just south of Oxford.
[EX A]: Which is the body of water by Sandford-on-Thames?

[EX Q]: Trimethylation of histone H3 Lys4 (H3K4) is associated with transcriptional activation. One of the chief effectors of H3K4 methylation is mixed-lineage leukemia 1 (MLL1), a gene that is disrupted by chromosomal translocation in acute leukemia and a master regulator of Hox and other genes. In a recent paper, core components of the human MLL histone methyltransferase (MT) complex were found to form a structural platform, with one component (WDR5) mediating association between the specific histone H3K4 substrate and the MT. This novel regulatory mechanism, which is conserved from yeast to human, is required for both methylation and downstream target gene transcription.
[EX A]:
Which is the histone residue methylated by MLL1?