What are the major characteristics of bacteria archaea fungi protozoa algae and viruses?

Answer 1

There are many differences, but I will mention a few:

A bacterium is a very small microorganism (a socalled prokaryot), with a cell wall and a cell membrane (or sometimes two) on the outside and with all the cellular machinery inside this one compartment.

A fungus is a much larger microorganism (a eukaryot), which is much more related to plants and animals. A fungus also has an outer cell wall and membrane, but inside the fungus there are several specialised compartments, e.g. the nucleus where the DNA is placed, mitochondria (which were many millions of years ago prokaryotic organisms) that helps the fungus with respiration, and many others. A fungus is most often long and threadlike, with several nuclei, so in stead of dividing upon replication of the DNA, the thread is extended, and the extra nucleus remains inside.

A virus is a very very small organism or particle. It has no life on its own as it lacks the necessary machinery to perform the reactions needed to sustain life. If a virus particle encounters a cell of the type it was evolved to infect, it will penetrate the cell and its genes will be interpreted by the machinery in this cell. The genes encode proteins that will combat and take over control of the cell machinery, replicate the virus DNA, assembly new vira and release the new vira to the environment. Often one virus particle will kill the cell and in the process spew out hundreds or thousands of new virus particles. There are viruses that attack human cells (a common cold will infact kill a bunch of your cells producing many more virus particles, which will kill more cells etc. until your immune defence will eventually get rid of them), but other viruses may attach bacteria, plants, animals etc.

A protozoa is a large single cell that can engulf bacteria, degrade them and live of the released nutrients. You could say that it is the smallest of predators.

Answer 2

there are different types of bacteria and viruses. bacteria is a type of micro-organism but virus is not as it shows both charateristics of living and non-living.

Answer 3

These do not have that much in common. Not all are small (fungi and algae), not all are green (algae), not all are even alive (viruses) nor do all contain DNA (viruses).