2. DEFINITIONS
• A gametangium (plural: gametangia) is an
organ or cell in which gametes are produced
that is found in many fungi, and the
gametophytes of plants.
• Sporangiophore (plural sporangiophores)
usually a stalk, A special type of hypha that
bears sporangia on the tip.
• A sporangium (plural: sporangia) is the
capsule structure belonging to fungi, in
which the reproductive spores are produced
and stored.
3. ZYGOMYCOTA
• Includes common bread molds
• Sexual reproduction occurs by fusion of
gametangia, formed zygospores.
• Asexual reproduction most common by non-
motile sporangiospores in the sporangium/
sporangia
• Sporangiophores form sporangia /sporangium
• Hyphae produce clumps of erect stalks
• A common example of this phylum is the bread
mold (Rhizopus stolonifera).
4.
5. CONT…
The mycelia of Zygomycota are divided into
three types of hyphae.
1. The rhizoids reach below the surface and
function in food absorption.
Above the surface,
2. Sporangiophores bear the spore-producing
sporangia.
3. Groups of rhizoids and sporangiophores are
connected above the surface by stolons.
9. • Reproduction
• Asexual reproduction in Zygomycota is similar to that in
other types of fungi, while sexual reproduction bears
some similarity to that in Ascomycota.
• Asexual Reproduction
• Asexual reproduction in Zygomycota varies greatly
among orders and species. Spores may be formed by the
separation and thickening of hyphal cells. They may also
be produced in specialized organs, whose structure is
also widely varied.
10. • Zygomycota have two mating types, though individual species
may only have one mating type.
• When hyphae from opposite mating types meet, they produce
structures called progametangia that are dense and
multinucleate. The structure, in some fungi, that develops into
the gametangium.
• Cell walls form to separate the tips of the progametangia into
gametangia,
• Plasmogamy then occurs between the two gametangia to form a
zygote.
Sexual Reproduction
11. CONT…
• Next, karyogamy takes place within the zygote.
• The cell walls of the zygote are thin at first, but later thicken
into a zygospore.
• Germination begins when the diploid nucleus undergoes
meiosis and a sporangium develops.
• Spores are produced within the sporangium.
12. CONT…
• Gametes are produced in the structures called gametangia.
• The key difference between sporangia and gametangia is
that sporangia are the asexual structures that produce
asexual spores while gametangia are the sexual structures
that produce sexual spores or the gametes.
The Zygomycota, or conjugation fungi
The most common ones encountered are the mold that affects bread, strawberries, and other fruits rich in sugar.
As they decompose plant material, soil, and dung, they play a vital role in the carbon cycle.
The Zygomycota, or conjugation fungi
The most common ones encountered are the mold that affects bread, strawberries, and other fruits rich in sugar.
As they decompose plant material, soil, and dung, they play a vital role in the carbon cycle.
coenogametes
Plasmogamy is a stage in the sexual reproduction of fungi, in which the protoplasm of two parent cells fuse without the fusion of nuclei, effectively bringing two haploid nuclei close together in the same cell. This state is followed by karyogamy, where the two nuclei fuse and then undergo meiosis to produce spores.
Heterokaryotic refers to cells where two or more genetically different nuclei share one common cytoplasm.
Karyogamy: Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei. Before karyogamy, each haploid cell has one complete copy of the organism's genome.
