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Sexual Reproduction-Reproduction in Fungi ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Sexual Reproduction : It takes place by the union of two cells(more often similar in size). The copulating pair of cells may be vegetative cells or ascospores. Yeasts may be homothallic or heterthallic. The stages of fusion are extremely variable and are discussed separately. a) Haplontic life cycle : This is exhibited by Schizosaccharomyces octosporus (fission yeast) which is homothallic. In this type of life cycle. Haploid stage (haplophase) is...
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Vegetative Reproduction ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Vegetative Reproduction : Yeast reproduces vegetatively either by fission or by budding. Depending on this character. They are grouped as fission yeast (Schizosaccharomyces) and budding yeast (Saccharomyces) 1. By fission : During reproduction by fission the parent cell elongates. The nucleus divides into two daughter nuclei and gradually a transverse partition wall is laid down somewhat near the middle, starting from periphery to the centre dividing the mother cell into...
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Life Cycle Yeast, Penicillium ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Life cycle events of (A) Yeast and (B) Penicillium are described below : Yeast Yeast are a group of non mycelial or  pseudomyelial ascomycetes which multiply asexually be budding or fission and where asci are not organi9sed into asococarps. These are facultative aerobes. Depending upon the mode of asexual reproduction ,  yeasts are of three types – budding yeast (e.g., Saccharomyces) , fission yeast (e.g., Schizosccharomyces) and helobial yeast (both ...
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Ascomycetes-The sac fungi ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Ascomycetes : The sac fungi The mycelium consists of septate hyphae (Yeasts are an exception in that they are basically unicellular). They are saprophytic, decomposers, parasitic or coprophilous (growing on dung). The septa possess central pores called septal pores. The pores allow communication and transport between adjacent cells. Cell wall contain chitin. Motile structures do not occur in the life cycle. In majority of ascomycetes. The common mode of asexual...
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Life cycle of Rhizopus ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Life cycle of Rhizopus Rhizopus is a saprophytic fungus, commonly found on dead organic matter rich in carbohydrates. Mycelium is made up of white narrow thread like hyphae growing on the surface of sub substratum. Two types of vegetative hypha (Rhizoidal and Stoloniferous) arise from definite points called hold fast / apparent nodes. Third hypha is asexual. Called Sporangiophore and fourth type is sexual hypha called. Zygophore. The absorptive hyphae...
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Classification of Fungi ”Biological Classification” Botany Notes Chapter 2, for Class 12-CBSE

Classification of fungi A number of criteria are used for classifying fungi morphology of mycellum , mode of spore formation and fruiting bodies form the basis of the classification of the kingdom. A common systematic presentation is given below : Oomycetes : The algal fungi Hyphal wall contains cellulose and other glucans in many members. The mycellum is coenocytic (multinucleate and aseptate) Asexual reproduction involves the formation of spore containing...
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