Slime Molds and Water Molds

The slime molds and water molds used to be considered types of fungus. They are, however, completely unrelated to the true fungi and are good examples of convergent evolution. Convergent evolution occurs when two organisms develop similar characteristics because of adaptations to similar environments and yet are not related on a molecular level (figure 12.19).

Acellular and Cellular Slime Molds

There are two groups of slime molds, the acellular slime molds and the cellular slime molds. The slime molds are terrestrial organisms living on soil, leaf litter, or the surfaces of decaying leaves or wood. They are non-motile, and reproduction depends on the formation of spores that can dispersed. Acellular slime molds are widespread and readily visible in their natural environment. Following sporulation and germination of the spores, ameboid cells fuse to form a myxameba. The nucleus of this ameba divides repeatedly, forming a multinucleated stage called a plasmodium. The plasmodium oozes like slime over the surface of decaying wood and leaves. As it moves, it ingests microorganisms, spores of other fungi, and any other organic material with which it comes in contact. Eventually the plasmodium is stimulated to form a spore-bearing fruiting body, and the process begins again (figure 12.20a).

The cellular slime mold has a vegetative form composed of single, ameba-like cells. When cellular slime molds run out of food, the single cells congregate into a mass of cells called a slug that then forms a fruiting body and spores. These fruiting bodies and spores look very much like fungal fruiting bodies and spores (figure 12.20b).

314 Chapter 12 The Eukaryotic Members of the Microbial World Animals

- Choanoflagellates

Spores

-Fungi-

- Zygomycetes -Ascomycetes -Basidiomycetes

-Chytridiomycetes

-Chlorophytes (green algae)

■ Cryptomonads

Rhodophyta (red algae)

Stramenophiles-

■ Chrysophyta (golden brown algae and diatoms) - Phaeophyta (brown algae)

Oomycetes (water molds)

Ciliates

■ Pyrrophyta - dinoflagellates

■ Apicomplexans

Cellular slime molds

Acellular slime molds

Entamoebids Amoeboflagellates ■ Kinetoplastids

Euglenoids

Parabasalians ■ Diplomonads - Microsporans

Bacteria

Figure 12.19 A Phylogenetic Scheme of Eukaryotes Based on rRNA

Sequence Comparisons The slime molds and water molds are highlighted in blue.

Fruiting bodies release spores

Spores

Fruiting bodies release spores

Myxamoebae

Fruiting body

Myxamoebae

Fruiting body

Cellular Slime Mould Life Cycle Images

Figure 12.20 Slime Molds (a) Life cycle of an acellular slime mold. (b) Fruiting body of a cellular slime mold.

Figure 12.20 Slime Molds (a) Life cycle of an acellular slime mold. (b) Fruiting body of a cellular slime mold.

Slime molds are important links in the food chain in the soil. They ingest bacteria, algae, and other organisms and, in turn, serve as food for larger predators. Slime molds have been valuable as unique models for studying cellular differentiation during their aggregation and formation of their fruiting bodies.

Oomycetes (Water Molds)

The oomycetes, or water molds, are members of a group of organisms known as heterokonts. The oomycetes do not have chlorophyll, whereas other heterokonts, which include the grass green algae, diatoms, and brown algae, have chlorophyll and other photosynthetic pigments. Oomycetes were once considered fungi because they look like fungi. They form masses of white threads on decaying material. They have flagellated re productive cells known as zoospores. Oomycetes cause some serious diseases of food crops. The late blight of potato (Phytophthora infestans) and downy mildew of grapes are included in this group. The late blight of potato was the cause of the potato famine in Ireland in the 1840s that sent waves of immigrants to the United States.

Bacterial Vaginosis Facts

Bacterial Vaginosis Facts

This fact sheet is designed to provide you with information on Bacterial Vaginosis. Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina.

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Responses

  • Sarah
    Does slime mould have green pigment for photosynthesis?
    4 years ago
  • Emppu Poutiainen
    Do slime moulds have green pigment chlorophyll for photosynthesis?
    4 years ago
  • GIRMAY
    Do slime mold and water molds cause disease?
    3 years ago
  • shirley
    What are the main characteristics of slime molds and water molds?
    3 years ago
  • Emppu
    What is the differences and similarities between water molds and slime molds?
    3 years ago
  • Jonas
    How are acellular and celluar alike and differnt in slime molds?
    3 years ago
  • oliwia
    Why slime molds and water molds fungi?
    3 years ago
  • BECKY
    Does slime mould possess green pigment chlorophyl for photosynthesis?
    3 years ago
  • alfredo
    What are the adaptive features of slime moulds?
    3 years ago
  • itala
    WHAT IS THE DIFFERENCE BETWEEN TERRESTRIAL MOLD AND WATER MOLD .?
    3 years ago
  • OLIWIER
    How do water molds reproduce?
    3 years ago
  • eemeli
    What isdiffirence between watare mold and slime momold?
    3 years ago
  • Doreen
    Why they are called slime and wateer mould?
    3 years ago
  • maxima
    Why they are colled slime and water mould?
    3 years ago
  • HEIKKI
    Why it is called water mould?
    3 years ago
  • eemil
    Why they are called water mould slime mould?
    3 years ago
  • FILMON
    What are characteristics of water mould?
    3 years ago
  • Max
    Do slime molds photosynthesize?
    3 years ago
  • howard
    Why water molds and slime molds are so named?
    2 years ago
  • Maria Grazia
    What is similar and different bteween whater mould and slime mould?
    2 years ago
  • ulderico
    What is the simmilarity bet wen slime molds and water molds?
    2 years ago
  • milena
    How is slime mold and water mold similarity?
    2 years ago
  • brendan
    Why slime mold and water mold are tremed?
    2 years ago
  • bellisima
    What is causative organism of mould?
    2 years ago
  • einojuhani
    What is similarities of water mold and slime molds?
    2 years ago
  • Lemlem
    What are the main differences between slime molds and water molds ?
    2 years ago
  • awet
    Why it called water mold?
    2 years ago
  • Clare
    Is phytophthora and slime are motile?
    1 year ago
  • Idris
    Do oomycotes have chlorophyll?
    1 year ago
  • Efisio Davide
    What are Slime Molds and Water Molds and what distinguish them from the true fungi.?
    1 year ago
  • kalevi
    What are slime molds and watet molds?
    1 year ago
  • Dillon
    What are slime molds and water molds and what distinguished from true fungi?
    1 year ago
  • RANIERO
    What is water molds and slime with picture?
    1 year ago
  • kinfe
    What are slime mold and water mold their unique difference?
    1 year ago
  • brendan
    What are slime molds and water molds their differences from Tru fungus?
    1 year ago
  • Ute
    How do water molds move?
    1 year ago
  • mari hautam
    Why slime mold and water molds are gymnomycota and oomycota respectively ?
    1 year ago
  • bradley
    What are slime molds and water molds and distniguish them from the true fungi?
    11 months ago
  • GILLY
    Why were the slime molds and water molds once considered to be fungi?
    9 months ago
  • Laila
    Why slime molds are called gymnomycota?
    8 months ago
  • Gertude
    Why aren't water molds considered to be a fungus?
    7 months ago
  • taina
    Are slime molds and water molds harmful?
    7 months ago
  • Courtney
    Are water molds heterotrophic and nonmotile?
    3 months ago
  • maxima
    What are two diseases caused by slime molds?
    3 months ago
  • feaven
    Which vegetative system forms slime molds?
    1 month ago
  • lavinia
    Are slime and water molds autotrophic or heterotrophic?
    19 days ago

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