fungi-1-rhizopus

fungi-1-rhizopus - grow on stale bread or rotting fruit,...

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Fungi 1 - Rhizopus The basic structural features of fungi are not cells but hyphae . Hyphae are microscopic branching threads. Each thread consists of a tube formed from a wall enclosing cytoplasm and a vacuole. The hyphal walls are not made of cellulose but of a substance called chitin , an organic nitrogenous compound. The hyphae contain many nuclei distributed throughout the cytoplasm. Sometimes the hyphae are divided into compartments by cross walls. The fungi do not have chlorophyll so they cannot make their food in the way that plants do. They feed on dead or decaying organic matter and are classed as saprophytes. Their hyphae penetrate the dead material and form a branching network called a mycelium . The tips of the growing hyphae produce enzymes which digest the organic material. The soluble products are absorbed into the hyphae. When mould fungi, such as Rhizopus,
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Unformatted text preview: grow on stale bread or rotting fruit, the mycelium can be seen as a greyish fuzz. Diagram of a section of a hypha Rhizopus is a mould fungus which grows on stale bread or rotting fruit. It reproduces asexually by sending up vertical hyphae. each of which swells at the tip to produce a sporangium . The cytoplasm in the sporangium divides repeatedly to produce a mass of spores , each with a nucleus. When the sporangium breaks open, the spores are dispersed in the air, and each can grow to form a new mycelium if it lands on suitable material. There is also a sexual method of reproduction. mycelium hyphae penetrating food sporangium sporangium broken open, spores escaping developing sporangium Rhizopus (x250) D.G. Mackean wall cytoplasm lining nucleus vacuole 5 (5 is 5 thousandths of a millimetre)...
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This note was uploaded on 11/29/2011 for the course BIO 218 taught by Professor Young during the Fall '11 term at BYU.

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