How do spirochetes and spirilla differ?
a) spirilla have an external flagella but spirochetes have axial filaments.
b) spirochetes do not have a cell wall but spirilla do.
c) spirochetes and spirilla are basically the same organisms and the terms can be used interchangeably.
d) spirilla are found in chains of cells whereas spirochetes exist as individual cells.
e) spirochetes have a rigid, corkscrew shape while spirilla are helical and more flexible.