[Music] The Zygomycetes The zygomycetes
include a variety of fungi. The black bread mold is a common zygomycete. It
decomposes bread, fruits, vegetables and decaying animals and produces a fuzzy
black growth on its substrate. Fewer than 1000 zygomycete species have been
identified and classified. Mycologists, scientists who study fungi, believe that
number represents only a small fraction of the total zygomycetes. All
zygomycetes form a zygospore as part of their sexual mode of reproduction.
Zygomycetes can reproduce both sexually and asexually. Asexual reproduction is by
spores formed in the sporangia. In nonseptate hyphae, cytoplasm flows freely
along the length of the hyphae enclosing many nuclei. The presence of
sporangia and nonseptate hyphae clearly indicate membership in this group of
fungi. There are not enough differences in the chemistry of fungi to indicate
gender. Fungi do however require different mating types in order to
sexually reproduce. In zygomycetes, two opposing mating types come together to
combine their haploid nuclei in a structure called a zygospore. A
zygospore often deposits thick chitin walls around itself to weather adverse
conditions. Under the right conditions, such as in the presence of moisture and
food, the zygospore haploid nuclei combine to form diploid nuclei. As is
true in members of this kingdom, fungi mostly exist in the haploid phase. So as
soon as syngamy occurs, the combining of the two haploid nuclei, meiosis
follows. The shuffling of the genes is accomplished in the meiotic process. In
the case of the zygomycetes, a hypha with a sporangium emerges out of the
zygospore ready to release its haploid spores. You have completed this learning object,
"The Zygomycetes".