Simplify the following text for a Grade 11 native English-speaking person.
Original: Chloroplasts have their own genome , which is considerably reduced compared to that of free-living cyanobacteria , but the parts that are still present show clear similarities with the cyanobacterial genome .
Simplified: Chloroplasts have their own genome , which is much smaller than that of free-living cyanobacteria . The DNA which remains shows clear similarities with the cyanobacterial genome .