Single-gene disorders are caused by mutations or changes that occur in the DNA grouping of a gene. ... Chromosomes are structures made up of DNA and protein. They are located in the nucleus of each cell. ... They are caused by changes in the nonchromosomal DNA of mitochondria. Because mitochondria come only from the egg, they are inherited exclusively from the mother. ...
Subclass Pelobiontae includes one genus, Pelomyxa, large cells which lack almost every characteristic of eukaryotic cells except the existence of a membrane-bound nucleus; these cells' nuclei divide like bacterial nucleoids. ... Many dinomastigotes have cells below the cell membrane that are capable of discharging a substance that stings prey. ... While the DNA of most other eukaryotes forms fibrils that are 10nm wide, the DNA of dinomastigotes is only 2.5 nm wide. Also, eukaryotic DNA usually only condenses during mitosis, but the DNA of organisms in this phylum is always condensed. ...
