Overview u u u Kingdom Fungi differ in

Overview u u u Kingdom Fungi differ in form, size and color Oldest fossils are 450500 million years old Most grow best in moist, warm environments between 20 -30°C Most are multicellular (except yeasts) Heterotrophic, Decomposers Phylum is replaced with divisions http: //www. naturegrid. org. uk/biodiv ersity/crypfungi. html

Structure of a Fungi Hyphae – threadlike filaments which develop from fungal spores u Hyphae elongate at their tips and branch extensively to form a network of filaments called a mycelium. u Mycelium – (many types) some anchor the fungus, others invade the food source, or function as a reproductive structure u

Plants versus Fungi Like plants, they grow anchored in the soil and have cell walls. u Unlike plants, which have cell walls made of cellulose, fungi use a complex carbohydrate called chitin. u Chitin gives the fungal cell walls both strength and flexibility. u

Fungal Feeding u There are 3 ways heterotrophic Fungi feed: – Saprophytes are decomposers and feed on waste or dead organic material. – Mutualists live in a symbiotic relationship with another organism like an alga. – Parasites absorb nutrients from the living cells of their hosts u Specialized hyphae called haustoria

Fungal Reproduction u u One important criterion for classifying fungi into divisions is their patterns of reproduction Fragmentation – pieces of hyphae broken off a mycelium grow into new mycelia. Unicellular fungi (yeast) reproduce by asexual budding. Most fungi produce spores: specialized mycelium called sporangium. – Protects the spores before being released and keeps them moist

Advantage of Spores u u Protection from harm (sporangium) Small & lightweight, can be dispersed by wind, water, animals – Wind can disperse a spore 100 s of kilometers. Produce a large number of spores at one time – A puffball 23 cm in circumference produces about 1 Trillion spores! – Greater survival in numbers Fungi can produce 2 types of spores: – Mitosis (asexual phase) – Meiosis (sexual phase)

Common Molds Members of Zygomycota u Called “Pin molds” or “sugar molds” u Attack breads & fruits u 900 species u Root-like hyphae called rhizoids penetrate the bread’s surface, stem-like hyphae called stolons run along the bread u

Sac Fungi Ascomycotes – have ascus, reproductive structure that contains spores u 30, 000 species u Includes: cup fungi, yeast, morels, truffles u

Club Fungi u u u Basidomycotes: have club-shaped hyphae (basidia) which produce basidospores 25, 000 species Include: puffballs, shelf fungus, mushrooms

Imperfect Fungi u u Deuteromycotes: reproduce asexually 25, 000 species Species are varied, can not be assigned to other phyla Includes penicillin, blue cheese veins

A unique fungi: Lichen u u u Lichen – a symbiotic association between a fungus & a green alga Only need light, air, minerals to grow Awesome case of Mutualism… – The photosynthetic alga provides the food for the organism – The fungus provides the alga with water, minerals and protects it from the environment.

Not So Great Fungi