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Kingdom Fungi

Biology

definition

Kingdom Fungi

1. Non-green, unicellular/multicellular, eukaryotic, heterotrophic and saprophytic organisms.
2. Has the presence of cell wall which is made up of chitin.
3. Most of them are made up of thread like hyphae rather than cells.
4. Reproduction in fungi is both by sexual and asexual means.
5. For example, yeast, moulds, mushrooms. Most common moulds (fungi) are Aspergillus and Penicillium.

definition

Deuteromycota

  • Their lack of sexual stages was the basis for them being called fungi imperfecti in the past.

  • Most Deuteromycota have only asexual reproduction as the sexual stage of the life cycle has been lost or has yet to be discovered.

  • There are a great number of human uses for these fungi; most significant is the production of antibiotics for medicinal use. These substances are produced by the fungus to inhibit the growth of other living organisms around themin particular, disease-causing bacteria. These substances are extracted from the fungus and are used to kill bacteria in the human body.

  • Economically important imperfect fungi are Penicillium and Aspergillus.

definition

Basidiomycota

  • The fungal group Basidiomycota, also known as the club fungi, includes some of the most familiar fungi.

  • Basidiomycetes play a key role in the environment as decomposers of plant litter. They are distinguished from other fungi by their production of basidiospores, which are borne outside a club-shaped, spore-producing structure called a basidium. These spores rarely germinate or mature.

  • For example, Agaricus (mushroom), Ustilago (smut), and Puccinia (rust fungus).

definition

Ascomycota

  • The sac-fungi produce spores in small cup-shaped sacs called asci, hence the name ascomycota.

  • The mature sac fungi spores are known as ascospores, they are released at the tip of the ascus breaks open.

  • Yeast is the most common one-celled fungi. Yeast reproduces through asexual process called budding. The buds form at the side of the parent cell, they pinch-off and grow into new yeast cell which is identical to the parent cell.

  • For example, Aspergillus, Claviceps, Neurospora.

definition

Sexual reproduction in fungi

Depending upon the compatibility in sexual reproduction, fungi are of two types homothallic and heterothallic. Sexual reproduction occurs by five methods. They are
  • Planogametic copulation
  • Gametangial contact
  • Gametangial copulation
  • Spermatogamy
  • Somatogamy

definition

Vegetative reproduction in fungus

It occurs by
  • Fragmentation
  • Budding
  • Fission
  • Sclerotia
  • Rhizomorphs

definition

Asexual reproduction in fungus

It is the type of reproduction in which special reproductive structures called spores or propagates are formed. Following are the types of spores produced in different groups of fungi.
  • Zoospores
  • Sporangiospores
  • Chlamydospores
  • Oidia
  • Conidia
  • Ascospores
  • Basidiospores
  • Binucleate spores

definition

Classification of phycomycetes

Phycomycetes are classified into oomycetes and zygomycetes.
  • Oomycetes (late blight, white rust, damping off, downy mildew)
  • Zygomycetes (squirting fungus, Rhizopus and Mucor)

definition

Types of phycomycetes

Phycomycetes is divisible into two groups, oomycetes and zygomycota.
Oomycetes
  • The mycelium is coenocytic.
  • Asexual reproduction involves formation of spore containing sacs.
  • Gametes are usually nonflagellate.
  • Sexual reproduction is by gametangial contact.
  • For example, Phytophthora, Albugo.
Zygomycota
  • The fungal group Zygomycota is most frequently encountered as common bread molds, although both freshwater and marine species exist.

  • Most of these live on decaying plant and animal matter found on the substrate.

  • They are usually recognized by their profuse, rapidly growing hyphae, but some exhibit a unicellular, yeast-like form of growth.

  • Asexual reproduction is by means of spores produced in sporangia borne on the hyphae. 

  • For example, Mucor, Rhizopus (the bread mould) and Pilobolus.

definition

Mode of nutrition of fungi

Fungal nutrition are of different types. They are
  • Saprotrophic
  • Parasitic
  • Symbiotic