Biology · BIOLOGICAL CLASSIFICATION

Which unique feature distinguishes *Mycoplasma* from all other organisms in Kingdom Monera?

1. They completely lack a cell wall and are the smallest living cells that can survive without oxygen.
2. They possess a thick chitinous cell wall and require high oxygen levels.
3. They are photosynthetic autotrophs possessing flagella.
4. They form thick silicified shells during vegetative reproduction.