Page 24 - Kingdom Protist

Oomycota which means water fungus is also called white rust fungus or downy
mildew. Oomycota body structure Oomycota are unicellular or multicellular organisms

with cellulose walls. Multicellular oomycota have hyphae that are smooth, not
insulated, and multinucleated (senocytic). Oomycota way of life Oomycota are
heterotrophic organisms that decompose dead organisms (saprophytes) or as
parasites on other organisms. Mode of reproduction Oomycota Oomycota reproduce
asexually and sexually. Asexual reproduction is done by forming two flagellated
zoospores. This reproduction is carried out if the environmental conditions are
favorable and there is plenty of food available. Meanwhile, sexual reproduction is
carried out by fertilization between an egg cell and a sperm nucleus which produces a

resistant zygote (oospore). This reproduction is carried out if the environment is in
poor condition.
Examples of Oomycota Organisms that are members of the Oomycota are as follows.
1). Saprolegnia sp. is a parasite on fish and insects that can live in fresh water with a
temperature of 3 – 330C. Several species of Saprolegnia include Saprolegnia australis
and Saprolegnia ferax.
2). Phytophthora sp. is a parasite on cultivated plants. Some of the Phytophthora
species are as follows.
3). Phythophthora infestans is a parasite on potato and tomato plants

Acrasiomycota are insulated slime molds. This fungus has a feeding phase in the form
of solitary living cells. However, if the food is depleted, these cells will form aggregates
(colonies) in a unit. In one aggregate unit, there are 125,000 cells. These aggregates
can move around. Acrasiomycota are haploid and the zygote is diploid. In the feeding

phase, solitary cells will form pseudo-legs. Acrasiomycota produce ameboid and
myxamoeba cells. (pseudopodia) to move and eat bacteria. Habitat Acrasiomycota live
in places that contain dirt and decaying vegetation. Acrasiomycota reproduce
asexually and sexually. Asexual reproduction is carried out by forming a fruiting body
which contains spores and has a supporting rod (stalk). Meanwhile, sexual
reproduction is carried out by means of syning with ameboid cells.

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