Biochemical data indeed suggest some affinity with animals. They are 'microorganisms' - either their structures cannot be seen with the naked eye, or they need microscopic examination, sometimes after growth in pure culture, for identification. The number of fungi described worldwide is estimated at around 70,000, but their total number may be as high as 1.5 million species. One reason for this discrepancy is that few data on fungi are available from the tropics. This clearly differentiates the Eumycota from true plants which have cell walls strengthened with cellulose.
Fungi contribute more biomass to soil than any other organisms.
They help to bind soil particles. Many are saprophytes, obtaining nutrition from dead plant and animal remains and so playing a vital role in decomposition and recycling nutrients. Fungi are of immense importance in the pharmaceutical industry. Virtually all antibiotics, notably penicillin, are derived from fungi. Also, yeasts are the basis of the baking, brewing and wine-making industries.