Range Number in Range Letter Grade 0-5 F 6-10 1 11-15 16-20 2 21-25 3 26-30 31-35 36-40 41-45 46-50 5 C 51-55 13 56-59 6 C+ 60-65 10 B- 66-70 B 71-75 76-79 B+ 80-85 7 A- 86-90 A 91-95 A+ 96-100 72
16600 bp in humans 37 genes 13proteins of about 90 proteins in the respiratory chain 2 ribosomal RNAs 22 tRNA 1000-10000 copies per cell 100000 per mammalian oocyte Heteroplasmic mtDNA mutations segregate during cell division Continous replication and turnover independent of cell cycle 1000-1200 different proteins