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.

Bracket or shelf fungi are lignocolous fungi which produce bracket or shelf-shaped, hard, leathery basidiocarps that are found to come out from the tree trunk on loss of wood, e.g., Fomes tomentarius, etc.

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.

HIV has two single RNA strands in its nucleoid. Reverse transcriptase enzyme catalyses the formation of DNA from RNA. It is found in some RNA viruses called retroviruses, e.g., HIV

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.

Monera

Copeland (1956).

Plantae, Protista, and Animalia

Ernst Haeckel (1866)

Linnaeus proposed the two kingdom classification in  1758

Aristotle divided animals in two groups. These are Enaima (with red blood ) and Enaima (without red blood)

There are millions of species on this planet.The largest phylum Arthropoda alone comprises of millions of species. To study all of them properly we need some system for categorizing them, based on some common characteristics.
Apart from that think of the differences in language and you will find different names for the same species in different languages.In the absence of a system of nomenclature it would have been difficult to share scientific knowledge among the scientists of different nations.
To make things easier and systematic the need for classification was felt.Earlier attempts by people like Aristotle segregated living beings into plants and animals.This was good point to start with, but there are certain living beings which do not fit in either of plants or animals.So a three kingdom classification was devised.The three kingdom classification was used for some time.But as none of the scientific theory is permanent so further discoveries led to creation of a five kingdom classification.The five kingdom classification is the most accepted system of classification.

Division of Kingdom Fungi :
The morphology of the mycelium, mode of spore formation and fruiting bodies form the basis for the division of the kingdom into various classes.
a) Phycomycetes :
Habit and Habitat : Members of phycomycetes are found in aquatic habitats and on decaying wood in moist and damp places or as obligate parasites on plants.
Mycelium : The mycelium is aseptate and coenocytic.
Reproduction : Asexual reproduction takes place by zoospores (motile) or by aplanospores (non-motile).

b) Ascomycetes : 
Habit and Habitat : Commonly known as sac-fungi,the ascomycetes are unicellular, e.g.yeast (Sacharomyces) or multicellular, e.g.Penicillium.They are saprophytic, decomposers, parasitic or coprophilous (growing on dung).
Mycelium :  Mycelium is branched and septate.
Reproduction : The asexual spores are conidia, produced exogenously on the special mycelium called conidiophores.
c) Basidiomycetes :
Habit and Habitat : Commonly known forms of basidiomycetes are mushrooms, bracket fungi or puffballs. They grow in soil, on logs and tree stumps and in living plant bodies as parasites, e.g., rusts and smuts.
Mycelium : The mycelium is branched and septate.
Reproduction :  The asexual spores are generally not found, but vegetative reproduction by fragmentation is common.
d) Deuteromycetes :
Habit and Habitat :  Some members are saprophytes or parasites while a large number of them are decomposers of litter and help in mineral cycling. Some examples are Alternaria, Colletotrichum and Trichoderma.
Reproduction : The deuteromycetes reproduce only by asexual spores known as conidia. The mycelium is septate and branched.

Fungus cells are eukaryotic. These cells contains all the eukaryotic organelles excepts plastids. Some of the organelles are the nucleus, ribosomes, endoplasmic reticulum, mitochondria, Golgi bodies, etc. A fungal cell wall contains mostly chitin. Plasmalemma bears coiled membranous outgrowths called lomasomes. Nuclei are small and connected to endoplasmic reticulum. Nuclear division involves formation of internal spindle. Vacuoles are small. Near the hyphal tips, the cytoplasm contains small vesicles called chitosomes. Food reserve is in the form of glycogen and oil.

(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.

Methanogens are a type of bacteria which live in the gut of ruminating animals.They assist those animals in digestion and the byproduct of that digestive process is methane.More number of livestock population results in increased methane level in the environment leading to global warming.So, indirectly methanogens can be responsible for global warming.

Difference between algae and fungi
(a) Algae is autotrophic, while fungi is heterotrophic.
(b) Algae cannot be a parasite, while fungi can be a parasite.