I believe that is what biologists call "viroids", which are much smaller than viruses, and as of yet are not completely understood. but if your asking for the answer for your homework and its not "viroids" its definitely "microbes" your welcome 100% on my tests ;)
The cell is considered the smallest unit of life. It is the basic structural and functional unit of all living organisms. Cells have the ability to carry out essential processes necessary for life, such as metabolism, growth, and reproduction.
The smallest form of germ or bacteria is known as a virus. Viruses are much smaller than bacteria and can only reproduce inside a living host.
Nanobacteria are some of the smallest known forms of life on Earth, measuring around 20-200 nanometers in size. They are extremely small bacteria-like organisms that have been a topic of scientific debate due to their size and properties.
What is the smallest number of glucose molecules that can form a polysaccharide?
The smallest known cells are typically bacteria known as mycoplasma, which lack a cell wall and have a simple structure. They are around 0.2 to 0.3 micrometers in size and are considered to be some of the smallest self-replicating organisms.