How does zygospore form

Krishan T. Sep 3, A zygote that secrets a thick wall around itself to be converted into a zygospore. Explanation: In Algae and Fungi, the haploid gametes fuse to form a diploid zygote. Related questions How do saprobes and parasites differ? How do fungi reproduce? How do fungi absorb nutrients? What are mycelium? These organisms were formerly classified in a group called the Zygomycota because they sexually reproduce by forming a structure called a zygospore. However, they have since been broken into several different lineages.

When the mycelium of one fungus encounters another fungus of the same species and a complementary mating type, it can start to produce compounds to interact with the new fungus. Through a series of chemical exchanges, the two fungi each begin to extend toward each other.

When they touch, they wall off an area of that extension by creating a septum. The walls between the gametangia of each fungus dissolve and the two fungi combine cytoplasm plasmogamy and then fuse the nuclei together karyogamy to form many diploid nuclei.

As this happens, a thick, orange, ornamented wall forms around the nuclei. This is the zygosporangium. The life cycle below shows both sexual and asexual reproduction in Rhizopus stolonifer. Both sexual and asexual reproduction result in the production of haploid spores that can germinate and grow into a haploid mycelium.

However, the spores produced by the mitosporangia will all be genetically identical, while the spores produced by the sporangia emerging from the zygosporangium will be genetically distinct. Watch the video below to see the microscopic structures involved in the asexual portion of the life cycle of Rhizopus stolonifer.

Sourced from YouTube. Most species are saprobes, living off decaying organic material; a few are parasites, particularly of insects. Zygomycetes play a considerable commercial role.

For example, the metabolic products of some species of Rhizopus are intermediates in the synthesis of semi-synthetic steroid hormones. Zygomycetes have a thallus of coenocytic hyphae in which the nuclei are haploid when the organism is in the vegetative stage. The fungi usually reproduce asexually by producing sporangiospores Figure 1. Figure 1. Zygomycete life cycle. Zygomycetes have asexual and sexual phases in their life cycles.

In the asexual phase, spores are produced from haploid sporangia by mitosis not shown. In the sexual phase, plus and minus haploid mating types conjugate to form a heterokaryotic zygosporangium.