BIOL 101 Lecture Notes - Lecture 9: Microsporidia, Mycorrhiza, Asexual Reproduction

• School: McGill University
• Department: Biology
• Course: BIOL 101
• Professor: Rudiger Krahe

Document Summary

Absorptive heterotrophs: organisms which secrete enzymes externally into the environment to digest organic materials which are then absorbed. Saprobes: organism that lives & feeds on dead organic matter. Saprotrophs: organism that feeds on or derives nourishment from decaying organic matter. Cell wall of chitin (poly-glucosamine) & glucans (polysaccharide) In many, hyphae divided into cell-like compartments by porous septae; cytoplasm is continuous. Some are coenocytic (common container) = no septae. Predatory: biological interaction where a predator feeds on its prey. Mutualistic (+/+) with plants, animals, algae, bacteria. Most of fungus is underground (huge surface for absorbing nutrients) Fruiting bodies = mushrooms formed for sexual reproduction. Mycorrhiza: mutualistic association of fungus with plant roots. Hyphae extend into soil & between plant cells. Long history; fossils of mycorrhizae older than vascular. E. g. fungal hyphae in stem of early land plant (devonian plants period) E. g. leaf cutter ants feed fungal colony, breaks down cellulose, hyphae fed to ant larvae, ants provide food & protection.