Introduction :
- The class zygomycetes includes those members in which the resting pores or zygospores develop by the fusion of two gametangia.
- Motile zoopores are absent.
- Members are saprophytic or weak parasite.
- Plant body is branched, filamentous, coenocytic.
- Cell wall is made up of chitin.
- Asexual reproduction takes place by aplanospores or chlamydospores or oidia.
- Sexual reproduction takes place by means of gametangial copulation which result in formation of zygospores.
Vegetative reproduction takes place by the following ways :
- Fragmentation
- Chlamydospore formation
- Oidia
- Fission
- Aplanospore
- Budding
- If fungi reproduces only by asexual spore then it is known as anamorphs.
- If fungi reproduces only by sexual spore then it is known as telomorphs.
- If fungi reproduces by both asexual and sexual spore then it is known as holomorphs.
- If some fungi produces more than one type of spores then it is known as pleomorphic or polymorphic.
- If spore produces inside the sporophores then it is known as endogenous spores.
- If spore produces outside the sporophores then it is known as exogenous spores.
Endogenous spores :-
- Producing spores within the sporangium.
- Sporangia are born on sporophores called sporangiophores
- Examples - Zoospores,Aplanospores
Exogenous spores :-
- Born on conidia.
- Examples - Only conidia
Sexual Reproduction :
- Sexual reproduction involves fusion of sex cells called gametes, which are formed in special structure called gametangia.
- In monoecious species, fusion of gametes occur on same hyphae.
- In dioecious species fusion of gametes occurs on different hyphae.
- Fungi having monoecious mycelia are homothallic and fungi having dioecious mycelia are heterothallic.
- Sexual reproduction involoves three stages
- Plasmogamy - Fusion of protoplast
- Karyogamy - Fusionn of nucleus
- Meiosis - Required to complete the lif cycle
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