The researchers studied the effects of deleting certain genes in cyanobacteria to see how it impacted chlorophyll distribution. By deleting specific genes related to photosystems, they found that even without PS II and PS I, some chlorophyll remained in the mutant strains. This remaining chlorophyll had similar characteristics to light-harvesting chlorophyll proteins found in plants. The role of this chlorophyll in the mutant strains is not fully understood, but it is likely connected to PS II when present.