Study Set Content:
f the dish is covered, the spores will sometimes germinate in as little as 15 minutes, but germination usually takes several hours or longer. Within a few days, a glistening mass of active slime mold protoplasmic material, looking something like the netted veins of a leaf, may appear. This material, whose veins tend to merge into the shape of a fan at its leading edges, is a
slime mold plasmodium.
The spores are often distributed throughout a jumbled mass of threads
capillitium
Phylum Myxomyxota - plasmodial slime molds Meiosis takes place in the
spores
When the spore germinates, one or more amoeba-like cells called
myxamoebae emerge
At first they feed on bacteria and other food particles, Sooner or later, however, they function gametes, fusing in pairs and forming zygotes.
myxamoebae
THE CELLULAR SLIME MOLDS
PHYLUM DICTYOSTELIOMYCOTA
Two or, more phyla of slime molds are recognized. Most of the species have typical plasmodia.
PHYLUM DICTYOSTELIOMYCOTA
When the population reaches a certain size, they stop feeding and clump together, forming a mass called
pseudoplasmodium
resembles, and crawls like a garden slug. It eventually becomes stationary and is transformed into a sporangiumlike mass of spores
pseudoplasmodium
contribute to ecological balance in forests and woodlands by breaking down organic particles to simpler substances
slime molds
Slime molds are often seen on what after rain
Bark mulch
one species of slime mold causes a
disease of watercress
THE WATER MOLDS
PHYLUM OOMYCOTA
water molds or
oomycetes
Coenocytic hyphae, not divided into individual cells, may form large masses of threads called
mycelia.
Reproduction of oomycytes
oogonia and antheridia
share several features with brown algae
water molds
completes its life cycle on grape leaves, usually killing the leaves and, if not controlled, the vine.
downy mildew of grapes
a combination of copper sulfate and lime (calcium oxide), inhibited downy mildew growth.
Bordeaux mixture
first substance known to have been used as a fungicide.
Bordeaux mixture
