tailieunhanh - Lecture Biology (6e): Chapter 31 - Campbell, Reece

Chapter 31 - Fungi. This chapter list the characteristics that distinguish fungi from other multicellular kingdoms, discuss mycorrhizal fungi, describe the processes of plasmogamy and karyogamy, describe the processes of plasmogamy and karyogamy. | CHAPTER 31 FUNGI Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Introduction to the Fungi 1. Absorptive nutrition enables fungi to live as decomposers and symbionts 2. Extensive surface area and rapid growth adapt fungi for absorptive nutrition 3. Fungi disperse and reproduce by releasing spores that are produced either sexually or asexually 4. Many fungi have a heterokaryotic stage Ecosystems would be in trouble without fungi to decompose dead organisms, fallen leaves, feces, and other organic materials. This decomposition recycles vital chemical elements back to the environment in forms other organisms can assimilate. Most plants depend on mutualistic fungi that help their roots absorb minerals and water from the soil. Human have cultivated fungi for centuries for food, to produce antibiotics and other drugs, to make bread rise, and to ferment beer and wine. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fungi are eukaryotes and most are multicellular. While once grouped with plants, fungi generally differ from other eukaryotes in nutritional mode, structural organization, growth, and reproduction. Molecular studies indicate that animals, not plants, are the closest relatives of fungi. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fungi are heterotrophs that acquire their nutrients by absorption. They absorb small organic molecules from the surrounding medium. Exoenzymes, powerful hydrolytic enzymes secreted by the fungus, break down food outside its body to simpler compounds that the fungus can absorb and use. 1. Absorptive nutrition enables fungi to live as decomposers and symbionts Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings The absorptive mode of nutrition is associated with the ecological roles of fungi as decomposers (saprobes), parasites, or mutualistic symbionts. Saprobic fungi absorb nutrients from nonliving organisms. | CHAPTER 31 FUNGI Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Introduction to the Fungi 1. Absorptive nutrition enables fungi to live as decomposers and symbionts 2. Extensive surface area and rapid growth adapt fungi for absorptive nutrition 3. Fungi disperse and reproduce by releasing spores that are produced either sexually or asexually 4. Many fungi have a heterokaryotic stage Ecosystems would be in trouble without fungi to decompose dead organisms, fallen leaves, feces, and other organic materials. This decomposition recycles vital chemical elements back to the environment in forms other organisms can assimilate. Most plants depend on mutualistic fungi that help their roots absorb minerals and water from the soil. Human have cultivated fungi for centuries for food, to produce antibiotics and other drugs, to make bread rise, and to ferment beer and wine. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings