Nucleus is not well defined in prokaryotes, which means that genetic materials are not enclosed in a capsule.
Nucleus is well defined in eukaryotes, which means that genetic materials are enclosed in a capsule.

Cell wall is present in bacteria, while cell wall is absent in protozoa.Some bacteria can be autotrophs,while all protozoans are heterotrophs.

Bacteria cause several diseases in human. Some of them are as follows: Tetanus, Tuberculosis, Cholera, etc.

Cynobacteria, also known as 'blue green algae' help in carbon fixation in a major way on the ocean surface.They are helpful in nitrogen fixation in paddy fields leading to a better harvest.About 80% of photosynthesis on ocean surface is done by cynobacteria.So, it can be said that they playa major role in our ecology.

(a) Ringworm
(b) AIDS
(c) Cholera
(d) Typhoid
(e) Ringworm.

(a) Curdling of milk
(b) Lactobacillus is an important commensal in the gut flora of humans.
(c) Penicillin antibiotics are prepared by bacteria.
(d) Bacteria is a good decomposer, so it assists in completing the energy cycle.
(e) Rhizobium bacteria helps in nitrogen fixation.

Differences between Monera and Protista

Difference between  dinoflagellates and euglenoids are

Protozoans take in water in bulk. As that mostly live in aquatic environments.They are highly likely to burst due to excessive in take of water.
Therefore, protozoans need to osmoregulate continuously to keep only the required amount of water in their cells. They get rid of excess water through contractile vacuoles.

Archaebacteria are able to tolerate high temperature ae well as  high acidity.
These bacteria are chemoautotrophic which obtain energy for synthesis of food by oxidising suphur. Under anaerobic conditions they oxidise sulphur to sulpuric acid.
2S + 2H₂O + 3O₂ \(\rightarrow\) 2H₂SO₄
Thermoacidophiles are able to tolerate high temperature as well as acidity, due to the presence of temperature as well as acidity due to the presence of 
(i) branched chain lipids in the cell membranes.
(ii) special resistant enzymes capable of operating under aerobic conditions.

Euglena is a taxonomic puzzle since, it shows both plant and animal characters. Absence of cell wall is an animal feature and presence of chloroplast is a plant character of Euglena. It have mixotrophic nutrition. In the presence of sunlight it can photosynthesise its food and in the absence of sunlight, it behaves like a hetrerotroph by predating on other smaller organisms.

Cyanobacteria are the most self contained photosynthetic organisms. They can, therefore, live under every type of environment and on every type of substrate. Because of this fact, they are one of the earliest colonizers of barren areas.

Malarial parasite Plasmodium has following two hosts
(i) Female Anopheles mosquito : It is a primary host of malarial parasite . The sexual phase of parasite occurs in mosquito.
(ii) Human being : These are intermediate or secondary host of plasmodium. The asexul phase of parasite occurs in human

Observable features in Trypanosoma are
(i) Unicellular, flagellum with basal granules.
(ii) Well-developed nucleus like eukaryotes.
(iii) Reproduces asexually
(iv) Reserved food material is in the form of granules.

Slime moulds possess the characters of both animal and fungi. Therefore, they are commonly called fungs animals. Modern biologists called them protistan fungi. They are like protozoa in their amoeboid plasmodial stage and similar to true fungi in spore formation.
Examples : Physarum, Physarella, Fuligo, Lycogala and Tubifers.