(a) Plasmodium causes malaria.
(b) Entamoeba histolytica causes amoebic dysentery.
(c) Trypanosoma causes sleeping sickness.

Bacterial viruses or bacteriophages (viruses that infect the bacteria) are usually double stranded DNA viruses.The bacteriophage enters its nuclear content inside the nucleus of bacteria.As a result the bacteria nucleus starts behaving like a virus and replicates more such viruses.

Lichens are a very good example of symbiosis.Lichens are combination of algae and fungi.The algal part provides food and base to the fungal part,while the fungal part provides gases to the algal part.They are supposed to be very good tool to identify level of pollution in a given ecosystem.

Animals are mobile.They show holozoic nutrition, i.e.,they ingest their food and break complex food substance into simpler compounds.Animals can be unicellular and multicellular.Reproduction is asexual and sexual

Eukaryotes have rRNA that is distinct from bacteria and archaeans. Plant and fungi organisms contain cell walls that are different in composition than bacteria. Eukaryotic cells are typically resistant to antibacterial antibiotics. Organisms in this domain include protists, fungi, plants, and animals.

According to five kingdom classification bacteria belong to the Kingdom Monera. Protista includes single-celled eukaryotes such Euglenoids, Protozoans etc. Plantae includes all eukaryotic chlorophyll-containing organisms commonly called plants.

Organisms like diatoms and desmids are called chrysophytes. They are found in both marine and freshwater and constitute the major phytoplanktons. Therefore, they are chief producers in the ocean. 

Mesosomes help in invagination of the membranes. Large septal mesosomes occur near centre of the cell and smaller lateral mesosome away from the centre. Septal mesosomes help in cell division and lateral mesosomes assist in the reproduction of bacterial DNA chromosome.

When female mosquito like Anopheles, suck human blood, it simultaneously injects a poisonous liquid containig protozoan cells into our blood. This poison causes the itching and causes swelling of the area.

The main criteria used for five kingdom system of classification are
(i) Complexity of cell structure.
(ii) Complexity of organism's body.
(iii) Mode of obtaining nutrition.
(iv) Life cycle and phylogenetic relationship.
(v) Presence or absence of sexual reproduction.

Viroids are free RNA molecules of low molecular weight without any protein coat while viruses can have either RNA or DNA molecules encapsulated in a protein coat. Viroids are smaller in size than viruses. Viroids infect only plants whereas virus infects all types of organisms. In viroids, a protein coat is absent whereas in viruses a protein covering or a coat called a capsid is present around the genetic material.

Some fungi have evolved essential relationships with the roots of many living plants.
These fungi grow around and into the roots. Both partners benefit so that neither would thrive without the other. This partnership is called mycorrhizal symbiosis.

Bacteriophages are viruses which kill bacteria. They are numbered T₁ to T₇ as their types. The shape of bacteriophages is tadpole - like with a head and a tail.

Plants are generally autotrophic.However, some plants like Nepenthes (pitcher plant), Utricularia (bladderwort), Venus fly trap and some parasites like Cuscuta are examples of partially heterotrophic plants. They supplement their nitrogen requirement by capturing and digesting insects.