20.1 Section Objectives – page 529

1. 20.1 Section Objectives – page 529 Section Objectives: 20.1 • Identify the basic characteristics of the fungi kingdom. • Explain the role of fungi as decomposers and how this role affects the flow of both energy and nutrients through food chains.

2. Section 20.1 Summary – pages 529-534 • _____ are everywhere—in the air and water, on damp basement walls, in gardens, on foods, and sometimes even between people’s toes.

3. Section 20.1 Summary – pages 529-534 • Some fungi are large, bright, and colorful, whereas others are easily overlooked. • Many species grow best in _______ environments at warm temperatures between 20°C and 30°C.

4. Section 20.1 Summary – pages 529-534 • Fungi used to be classified in the plant kingdom because, like plants, many fungi grow anchored in soil and have ___ ___. • However, as _________ learned more about fungi, they realized that fungi belong in their own kingdom.

5. Section 20.1 Summary – pages 529-534 • Although there are a few unicellular types of fungi, such as _____, most fungi are multicellular. • The basic structural units of multicellular fungi are their threadlike filaments called ______ (HI fee) (singular, hypha), which develop from fungal spores.

6. Section 20.1 Summary – pages 529-534 The structure of fungi Germinating Spore Mycelium Spore Food Source

7. Section 20.1 Summary – pages 529-534 • There are different types of hyphae in a ______. Some _____ the fungus, some _____ the food source, and others form fungal reproductive structures.

8. Section 20.1 Summary – pages 529-534 • Unlike plants, which have cell walls made of _______, the cell walls of most fungi contain a complex carbohydrate called ____ (KI tun). • _____ gives the fungal cell walls both strength and flexibility.

9. Section 20.1 Summary – pages 529-534 • In many types of fungi, cross walls called ___ (singular, septum) divide hyphae into individual cells that contain one or more nuclei. • Septa are usually _____, allowing cytoplasm and organelles to flow freely and nutrients to move rapidly from one part of a fungus to another.

10. Section 20.1 Summary – pages 529-534 Septum Nuclei Cell Wall Cytoplasm

11. Section 20.1 Summary – pages 529-534 • Some fungi consist of hyphae with no septa. Nuclei Cytoplasm Cell Wall

12. Section 20.1 Summary – pages 529-534 • Under a microscope, you see hundreds of nuclei streaming along in a continuous flow of _________. • As in hyphae with septa, the flow of cytoplasm quickly and efficiently disperses ______ and other materials throughout the fungus.

13. Section 20.1 Summary – pages 529-534 • Fungi can be ______. • Some cause food to _____. Some cause _______, and some are _______. However, they play an important and beneficial role. • In a world without fungi, huge amounts of wastes, dead organisms, and debris, which consist of complex _____ substances, would litter Earth.

14. Section 20.1 Summary – pages 529-534 • Many fungi, along with some bacteria and protists, are _____________. • They break down ________ organic substances into raw materials that other living organisms need.

15. Section 20.1 Summary – pages 529-534 • Fungi are ________, and they use a process called _________ digestion to obtain nutrients. • In this process, food is digested outside a fungus’s cells, and the digested products are then _______.

16. Section 20.1 Summary – pages 529-534 Hyphae absorb the digested food. Chemicals released by hyphae digest dead materials.

17. Section 20.1 Summary – pages 529-534 • For example, as some hyphae grow into the cells of an orange, they release digestive ________ that break down the large organic molecules of the orange into smaller molecules.

18. Section 20.1 Summary – pages 529-534 • These small molecules _____ into the fungal hyphae and move in the free-flowing cytoplasm to where they are needed for growth, repair, and reproduction.

19. Section 20.1 Summary – pages 529-534 • A fungus may be a _______, a ______, or a _______ depending on its food source. • Saprophytes are ________ and feed on waste or dead organic material. • Mutualists live in a s_______ relationship with another organism, such as an alga. Parasites _____ nutrients from the living cells of their hosts.

20. Section 20.1 Summary – pages 529-534 Fungal hypha Host cell Haustorium

21. Section 20.1 Summary – pages 529-534 • Depending on the species and on environmental conditions, a fungus may reproduce _______ or ________. • Fungi reproduce sexually by ________, ______, or producing ______.

22. Section 20.1 Summary – pages 529-534 • In fragmentation, pieces of hyphae that are broken off of a _______ grow into new mycelia.

23. Section 20.1 Summary – pages 529-534 • The unicellular fungi called yeasts often reproduce by a process called budding—a form of ______ reproduction in which ______ occurs and a new individual pinches off from the parent, matures, and eventually separates from the parent. Yeast budding

24. Section 20.1 Summary – pages 529-534 • Most fungi produce _______. • When a fungal spore is transported to a place with favorable growing conditions, a threadlike ____ emerges and begins to grow, eventually forming a new mycelium. • The ___________ becomes established in the food source.

25. Section 20.1 Summary – pages 529-534 Spores Bread Mold Sporangium Hyphae

26. Section 20.1 Summary – pages 529-534 • Many fungi can produce two types of spores—one type by mitosis and the other by ______—at different times during their life cycles. • One important criterion for classifying fungi into divisions is their patterns of _______, especially sexual reproduction, during the life cycle.

27. Section 20.1 Summary – pages 529-534 • Many adaptive advantages of fungi involve ______ and their production.

28. Section 20.1 Summary – pages 529-534 • First, the ______ protect spores and, in some cases, prevent them from drying out until they are ready to be released. • Second, most fungi produce a _____ number of spores at one time.

29. Section 20.1 Summary – pages 529-534 • Producing so many spores increases the _________ rate and improves the species survival chances. • Finally, fungal spores are small and lightweight and can be dispersed by ____, water, and animals such as ____ and insects.

30. Section 1 Check The answer is A, spores. Spores Bread Mold Sporangium Hyphae

31. 20.2 Section Objectives – page 535 Section Objectives 20.2 • Identify the four major phyla of fungi. • Distinguish among the ways spores are produced in zygomycotes, ascomycotes, and basidiomycotes. • Summarize the ecological roles of lichens and mycorrhizae.

32. Section 20.2 Summary – pages 535-543 • You have probably seen Rhizopus stolonifer, a common ____ mold.

33. Section 20.2 Summary – pages 535-543 • Rhizopus is probably the most familiar member of the phylum ______________ (zy goh mi KOH tuh). • Many other members of about 1500 species of zygomycotes are also ____________.

34. Section 20.2 Summary – pages 535-543 • Zygomycotes reproduce asexually by producing ______. • They produce a different type of spore when they reproduce sexually. • The _____ of zygomycotes do not have septa that divide them into individual cells.

35. Section 20.2 Summary – pages 535-543 • When a Rhizopus spore settles on a moist piece of bread, it _________ and hyphae begin to grow. • Some hyphae called ______ (STOH lunz) grow horizontally along the surface of the bread, rapidly producing a mycelium.

36. Section 20.2 Summary – pages 535-543 • Some other hyphae form ______(RI zoydz) that penetrate the food and anchor the mycelium in the bread. • Rhizoids secrete _______ needed for extracellular digestion and absorb the digested nutrients.

37. Section 20.2 Summary – pages 535-543 • Asexual reproduction begins when some hyphae grow upward and develop _______ at their tips. Asexual spores develop in the sporangia. • When a _________ splits open, hundreds of spores are released.

38. Section 20.2 Summary – pages 535-543 Bread Mold Spores Sporangium Hyphae

39. Section 20.2 Summary – pages 535-543 • When zygomycotes reproduce sexually, they produce ______ (ZI guh sporz), which are thick-walled spores that can withstand unfavorable conditions.

40. Section 20.2 Summary – pages 535-543 • Sexual reproduction in Rhizopus occurs when ______ hyphae from two compatible mycelia, called ___ and _____ mating strains, grow together and fuse. • Where the haploid hyphae fuse, they each form a _______- (ga muh TAN ghee uhm), a structure containing a haploid nucleus.

41. Section 20.2 Summary – pages 535-543 Spores (n) Spores (n) Sporangia Sporangium - Mating strain (n) Hypha + Mating strain (n) Gametangia Zygospore Stolon Meiosis Rhizoids Germination Asexual Reproduction Sexual Reproduction

42. Section 20.2 Summary – pages 535-543 • When the haploid nuclei of the two gametangia fuse, a ________ zygote forms. • The zygote develops a thick wall, becoming a dormant zygospore.

43. Section 20.2 Summary – pages 535-543 • When environmental conditions are favorable, the zygospore absorbs water, undergoes ______, and germinates to produce a hypha with a sporangium. • Each ______ spore formed in the sporangium can grow into a new mycelium.

44. Section 20.2 Summary – pages 535-543 • The ___________ is the largest phylum of fungi, containing about 30,000 species. • The ascomycotes are also called __ fungi. Both names refer to tiny saclike structures, each called an ____, in which the sexual spores of the fungi develop. • Because they are produced inside an ascus, the sexual spores are called ___________.

45. Section 20.2 Summary – pages 535-543 • During asexual reproduction, ascomycotes produce a different kind of ______. Conidiophores • Fungal hyphae grow up from the mycelium and elongate to form ________________ (kuh NIH dee uh forz).

46. Section 20.2 Summary – pages 535-543 • Chains or _____ of asexual spores called conidiadevelop from the tips of conidiophores. Conidiophores

47. Section 20.2 Summary – pages 535-543 • Sac fungi are familiar to farmers and gardeners because they cause plant diseases such as apple ___ and ___ of rye. • Not all sac fungi have a bad reputation. Ascomycotes can have many different forms.

48. Section 20.2 Summary – pages 535-543 • ______ and ______ are two edible members of this phylum.

49. Section 20.2 Summary – pages 535-543 • Perhaps the most economically important ascomycotes are the ______. • Yeasts are unicellular sac fungi that rarely produce hyphae and usually reproduce asexually by _____. • Yeasts are ________ and ferment sugars to produce carbon dioxide and ethyl alcohol.

50. Section 20.2 Summary – pages 535-543 • Because yeasts produce alcohol, they are used to make wine and beer. • Other yeasts are used in _____ because they produce carbon dioxide, the gas that causes bread dough to rise and take on a light, airy texture.