推 DOMONIC:動作會不會太快了......... 11/13 16:29
推 winterkiller:感謝感謝再感謝 對於今日睡到十一點多起床的我 11/13 20:03
→ winterkiller:真是天降甘霖啊!! 11/13 20:03
推 gemini7767:冬殺~今天15章講完了喲!(老師那段沒放power point...) 11/13 20:57
Fungi
1. absorptive nutrition enables fungi to live as decomposers and symbionts
2. extensive surface area and rapid growth adapt for absorptive nutrition
the vegetative bodies of most fungi are constructed of tiny filaments called hyphae(菌絲) that form an interwoven mat called a mycelium(菌絲體)
3. fungi disperse and reproduce by releasing spores tat are produced either sexually or sasexually
4. many fungi have a heterokaryotic stage
Ecosystems would be in trouble without fungi to decompose dead organisms
Most plants depend on mutualistic fungi that help their roots absorb minerals and water from the soil
Fungi are eukaryotes and most are multicellular
Saprobic fungi腐生菌
Parasitic fungi寄生菌
Mutualistic fungi共生菌
Most fungi are multicellular with hyphae divided into cells by cross walls, or septa.
Fungi that lack septa, coenocytic fungi
Fungi mycelia can be huge, but they usually escape notice because they are subterranean.
Parasitic fungi usually have some hyphae modified as haustoria吸器, nutrient-absorbing hyphal tips that penetrate the tissues of their host.
In many fungi with sexual life cycles, karyogamy, fusion of haploid nuclei contributed by two parents, occurs well after plasmogamy, cytoplasmic fusion by the two parents.
The delay may be hours, days, or even years.
More than 100000 species of fungi are known and mycologists estimate that there are actually about 1.5 nillion species worldwide.
Molecular analyses supports the division of the fungi into four phyla.
Phylum chytridiomycota: chytrids may provide clues about fungal origins
The chytrids are mainly aquatic
790 species
Some are saprobes, while others parasitize protists, plants, and animals.
The presence of flagellated zoospores had been used as evidence for excluding chytrids from kingdom fungi which lack flagellated cells.
However, recent molecular evidence supports the hypothesis that chytrids are the most primitive fungi.
Phylum zygomycota: zygote fungi form resistant structures during sexual reproduction
Most of the 600 zygomycete, or zygote fungi, are terrestrial, living in soil or on decaying plant and animal material.
Mycorrhizae
The life cycle and biology of Rhizopus stolonifer, black bread mold, is typical of zygomycetes.
The zygosporangia are resistant to freezing and drying.
When conditions improve, the zygosporangia release haploid spores that colonize new substrates.
Phylum ascomycota: sac fungi produce sexual spores in saclike asci
Mycologists have described over 60000 species of ascomyctes, or sac fungi.
They range in size and complexity from unicellular yeasts to elaborate cup fungi and morels.
Ascomyctes live in a variety of marine, freshwater, and terrestrial habitats.
Some are devastating plant pathogens.
Many are important saprobes, particularly of plant material.
The defining feature of the ascomycota is the production of sexual spores in saclike asci
Ascomyctes reproduce asexually by producing enormous numbers of asexual spores, which are usually dispersed by the world.
--
今兒聽君一席話
星空吹起蕭澀風 秋的鬱
飄下孤潔雪 冬的漠
星不晴
敬你我過往最傷心
夢星晴
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.4.247