Experimental evidence suggests that the nucleoid is largely composed of DNA, about 60%, with a small amount of RNA and protein. The latter two constituents are likely to be mainly messenger RNA and the transcription factor proteins found regulating the bacterial genome.
An ophthalmologist is a medical doctor (MD) or an osteopathic doctor (DO) who specializes in eye and vision care. Ophthalmologists are trained to perform eye exams, diagnose and treat disease, prescribe medications and perform eye surgery. They also write prescriptions for eyeglasses and contact lenses.
DO stands for Doctor of Osteopathic Medicine, and refers to a doctor who practices medicine whose medical school training included a focus on the muscular and skeletal systems to treat problems throughout the body. Both MD's and DO's attend medical school and take exams to become licensed, practicing physicians.