biology 4 answers

7. There are six major phyla in kingdom Fungi. Members of phylum Basidiomycota form sexual spores on clublike basidia. Members of phylum Ascomycota form sexual spores in saclike asci. Members of phylum Zygomycota form sexual spores where hyphae fuse. Members of phylum Chytridiomycota form spores with flagella. Members of phylum Deuteromycota have no known form of sexual reproduction and are sometimes called imperfect fungi. Members of phylum Myxomycota are placed in kingdom Protista by some biologists, because they resemble protozoa for much of their lives.

8. Mushrooms make up most of the organisms in phylum Basidiomycota. In the mushroom life cycle, mycelia grow from spores. Two mycelia will fuse for sexual reproduction. The resulting mycelium will grow, crowding out the parent mycelia. Eventually, many hyphae will enclose themselves in a membrane, forming the button stage of the mushroom. A fruiting body will eventually emerge from the membrane, and it will be composed of three basic components: stipe, cap, and gills. The spores are formed on basidia found in the gills. Those basidia release spores, from which new mycelia will grow.

There are many forms of specialized hyphae. Rhizoid hyphae are embedded in the material on which the fungus grows. Aerial hyphae are not embedded in the material on which the fungus grows. If such a hypha produces spores, it is a sporophore, but if it asexually produces more filaments, it is a stolon. In the case of a fungus that feeds on a living organism, a hypha that enters the cells of the living organism and draws nutrients directly from the cytoplasm of those cells is called a haustorium.

All fungi are assumed (but not all are confirmed) to have some sexual mode of spore formation.

17. Members of phylum Myxomycota are often called slime molds. They tend to resemble protozoa during their feeding stage, and during this time, the mass of living tissue is called a plasmodium. During their reproductive stage, these organisms resemble fungi.

18. There is no such thing as an unbiased scientist.

The five features common to most fungi are saprophytic feeding, extracellular digestion, reproduction by spores, multicellular makeup (you could say hyphae instead), and cell walls containing chitin.

The cells in some hyphae are separated by cell walls. Thus are called septate hypha. Other hyphae, called nonseptate hyphae, have no separations between the cells, and the nuclei are spread throughout the hypha. Even septate hyphae have pores through which cytoplasm is exchanged.

9. The mycelium of a mushroom tends to grow outward in circular patches. Because it can run out of food in the center, the fruiting bodies of the fungus can sometimes form a fairy ring.

10. Puffball fungi are part of phylum Basidiomycota and grow spores inside a membrane. When disturbed, the spores are pushed out a hole near the top of the membrane. Shelf fungi are also in this phylum and grow shelflike structures on both dead and living wood.

13. Other members of phylum Ascomycota include morels (that have fruiting bodies which look like sponges), cup fungi (that have fruiting bodies which look like cups), ergot of rye or Claviceps purpurea (that feeds on rye grain and is deadly to people), and tree parasites that cause Dutch elm disease and Chestnut Blight.

14. The spores formed by fungi in phylum Zygomycota are called zygosoores which are composed of a hard, protective coating around a zygote.

15. Bread mold is in phylum Zygomycota. It forms asexual spores in sporangiophores.

16. Fungi in genus Penieillium are in phylum Deuteromycota. They produce the first antibiotic ever discovered, which revolutionized the treatment of infections. Some bacteria have adapted to be immune to these infection-fighting compounds, which means new ones must continually be found.

11. Rusts and smuts are examples of parasitic fungi in phylum Basidiomycota. Such a fungus tends to live most of its life cycle on one host, which is called its main host. However, it must also spend a certain part of its life cycle on an alternate host.

12. Yeast are single-celled members of phylum Ascomycota that asexually reproduce by budding. They are used in fermentation, which anaerobically breaks down sugars into smaller molecules, such as carbon dioxide and alcohol. The former can make bread dough tiR and the latter can be used to make alcoholic beverages.

19. A lichen is a mutualistic relationship between a fungus and an alga. The alga produces food for itself and the fungus by means of photosynthesis, while the fungus gives swoons and protection to the alga. Most lichens reproduce by releasing a dust-like substance called a soredium which contains spores of both the alga and the fungus in a protective case.

20. A mycorrhiza (or fungus root) is a mutualistic relationship between a fungus and a plant root. The fungus absorbs nutrients from the roots and gives the plant minerals in return.

5. Sexual reproduction in fungi usually involves forming specialized spore-forming structures called fruiting bodies, which are the result of sexual reproduction between compatible hyphae.

6. One mode of asexual reproduction in fungi involves the lengthening of a stolon. After it reaches a certain length, it will begin to reproduce into hyphae that will form the mycelium of a new fungus.