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Monday, 6 April 2015

FSc Notes Biology Part 1 Chapter 8 Fungi

           FSc Notes Biology Part 1 Chapter 8 Fungi

Q 1. What is hypha?
Ans. Hypha is a long, slender, branched and thread like filament of fungal body.

Q 2. What are fungi?
Ans. The eukaryotic organisms which have cell wall but cannot synthesize their food are called fungi.

Q 3. What is mycelium?
Ans. Mycelium is body of fungi which represent group of hyphae.

Q 4. What do you mean by Bio-remediation?
Ans.  Bioremediation means degrading or removal of environmental poisons or pollutants by the help of organisms.

Q 5. What is haustoria?
Ans. There are special hyphae produced in parasitic fungi. These hyphae penetrate into the host tissue and absorb food.

Q 6. What is the advantage of incomplete septa in septate hyphae?
Ans. Septa of many septate fungi have a pore through which cytoplasm flows from cell to cell, carrying materials to growing tips.

Q 7. Why yeasts are different from other fungi?
Ans. Yeasts are different from other fungi as they are unicellular.

Q 8. Name sexual and asexual spores of Ascomycota.
Ans. Sexual spores are called ascospores borne in asci while asexual spores are called conidia in Ascomycota.

Q 9. What are the main types of mycorrhiza?
Ans. (i) Endomycorrhizae: In which fungal hyphae penetrate the outer cell of the plant root, forming coils, swellings and minute branches, and also extend out into surrounding soil.
(ii) Ectomycorrhizae: In which the hyphae surround and extend between the cells but do not penetrate the cell wall of the roots. These are found in pines, firs etc.

Q 10. Why is green mould more likely to contaminate an orange kept in refrigerator than the bacteria?
Ans.  Fungi can tolerate temperature extremes 5-6 C below freezing and hence are more likely to contaminate an orange kept in a refrigerator than the bacteria.

Q 11. How fungi gets its nutrients?
Ans.  (i) Most fungi are decomposers i.e., obtain food from dead organisms. e.g., Yeast, Agaricus.
(ii) Some fungi are parasites i.e., obtain food from living host. e.g., rust and smut.
(iii) Some are predators e.g. Arthrobotrys.

Q 12. What do you mean by term karyogamy?
Ans. The fusion of nuclie in different mycelia is called karyogamy.

Q 13. What are yeasts?
Ans. Yeasts are unicellular microscopic fungi which are non-hyphal in structure.

Q 14. What is parasexuality?
Ans. The exchange of portion of chromosomes of two nuclei lying in the same hyphae.

Q 15. What are the benefits of mycorrhizae?
Ans.  The fungal hyphae of mycorrhizae increase the amount of soil contact and total surface area for absorption and help in direct absorption of minerals and nutrients from the soil.

Q 16. Name any four important fungal diseases of plants.
Ans.  (i) Rusts (ii) Smuts (iii) Powdery mildews (iv) Potato wilt

Q 17. Name any important fungal disease of humans.
Ans.  (i) Ringworm (ii) Aspergillosis (iii) Histoplasmosis (iv) Oral and vaginal thrush.

Q 18. Some enzymes of fungi are useful on one hand and harmful on other. Discuss.
Ans.  Some fungal enzymes are used in fermentation and brewing industry but digesting enzymes of some saprotrophic fungi spoil our food, plastic, paper and textile.

Q 19. What do you mean by Rust?
Ans.  It is a fungal disease of plants. As its color is brown like that of iron, so it is called as rust.

Q 20. What is the difference between dikaryotic and diploid?
Ans. Fungal cells having two nuclei of different genetic make up are called dikaryotic while having two sets of chromosomes in the nucleus of a cell or hypha is called diploid condition.

Q 21. Define obligate parasites.
Ans. Obligate parasites can grow only on their living host and cannot grow on available defined growth culture medium. For example many suit species.

Q 22. Differentiate between plasmogamy and karyogamy?
Ans. Fusion of cytoplasm is plasmogamy and fusion of nuclei is karyogamy.

Q 23. Define facultative parasite.
Ans. They can grow parasitically on their host as well as by themselves on artificial growth media.

Q 24. What are ascospores?
Ans. Most sac fungi have asci inside macroscopic fruiting bodies called ascospores, the visible morels.

Q 25. Write two differences between fungal and animal.
Ans. Fungi are different from animals as:
(i)They are non-motile.
(ii)They have absorptive mode of nutrition.

Q 26. What is ergotism?
Ans. Ergotism is caused by eating bread made from purple ergot-contaminated rye flour. The poisonous material in the ergot causes nervous spasm convulsion, even gangrene.

Q 27. What is the method of traping nematodes in arthrobotrys?
Ans. Some species of Arthrobotrys trap soil nematodes by forming constricting ring, their hyphae invading and digesting unlucky victim.

Q 28. How asexual reproduction takes place in fungi?
Ans. Asexual reproduction takes place by spores, conidia, fragmentation and budding.

Q 29. What is Rhodotorula?
Ans. Rhodotorula is a pink yeast which grows on shower curtains and other moist surfaces.

Q 30. Give a single characteristic that differentiates zygomycota from basidiomycota.
Ans. Zygospores are formed in zygomycota while basidiospores are the sexually reproducing spores in basidiomycota.

Q 31. What is the composition of fungal cell wall and how is this composition advantageous to fungi.
Ans. Cell wall of fungi is composed of chitin, which is more resistant to decay than are cellulose and lignin which make up plant cell wall.

Q 32. What do you mean by histoplasmosis?
Ans. It is serious infection of lungs caused by inhaling spores of a fungus, which is common in soil contaminated with bird's feces.

Q 33. Write two similarities of plants with fungi?
Ans. They resemble plants in some respects i.e.
(i) They have cell wall.
(ii) They lack centrioles and are non-motile.

Q 34. Write two dissimilarities of plants with fungi?
Ans. They differ plants as:
(i) Fungi are heterotrophs.
(ii) They lack cellulose in their cell walls and contain chitin.

Q 35. Differentiate between the members of Spore / Conidium.
Ans. Spore / Conidium: Spores are non-motile, small asexual structures produced inside the reproductive structures called sporangia, which are cut off from the hyphae by complete septa. Conidia are non-motile, asexual spores which are cut off at the end of modified hyphae called conidiophores, and not inside the
sporangia, usually in chains or clusters.

Q 36. Differentiate between the members of  Ascus / Basidium.
Ans. Ascus / Basidium: Basidiomycotes have sexual reproductive structure, the basidium, on which basidiospores are formed. Ascomycetes produce haploid sexual spores called ascospores inside their characteristic sac like structures called asci.

Q 37. Differentiate between the members of  Dikaryotic / diploid.
Ans.  Dikaryotic / diploid: A fungal hypha / cell having 2 nuclei of different genetic types is called dikaryotic hypha / cell. A cell or organism having full set of chromosomes e.g., 46 or 23 pairs in man, is called diploid.

Q 38. Differentiate between the members of Ascocarp / Ascus.
Ans.  Ascocarp / Ascus: Ascus is the characteristic sac like structure in which ascoposores are formed by meiosis while ascocarp is the macroscopic fruiting body in which asci are present.

Q 39. Differentiate between the members of  Obligate parasite / Facultative parasite.
Ans.  Obligate parasite / Facultative parasite: Obligate parasites can grow only on their living host and cannot be grown on available defined growth culture medium e.g., various mildews and most rust species. Facultative parasite can grow parasitically on their host as well as by themselves on artificial growth media

Q 40. Differentiate between the members of Endomycorrhizae / Ectomycorrhizae.
Ans.  Endomycorrhizae, in which the fungal penetrate the outer cell of the plant root, forming coils, swellings and minute branches, and also extend out into surrounding soil.
Ectomycorrhizae, in which the hyphae surround and extend between the cells but do not penetrate the cell walls of the roots. These are mostly formed with pines, firs etc. However, the mycelium extends far out into the soil in both kinds of mycorrhizae.

Q 41. Differentiate between the members of  Plasmogamy / Karyogamy.
Ans.  Plasmogamy / Karyogamy: The fusion of nuclei is called karyogamy while the fusion of cytoplasm is called plasmogamy.

Q 42. What are Hyphae? What is the advantage of having incomplete septa?
Ans. Hyphae: Mycelium consists of long slender, branched, tubular, thread like filaments called hyphae. Hyphae spread extensively over the surface of substratum. Their cell walls are composed of chitin, so their wall is highly resistant to decay. Hyphae may be septate or non-septate.
Advantage of having incomplete Septa: Cytoplasm flow from cell to cell, carrying the materials to growing tips and enabling the hyphae to grow rapidly when food and water are abundant and temperature is favorable.

Q 43. What is the composition of fungal cell wall and how it is this composition advantageous to fungi?
Ans. Fungal cell wall are composed of chitin, so their wall is more resistant to decay than cellulose and lignin which make up plant cell wall.

Q 44. To which phyla do the yeasts belong? How they differ from other fungi?
Ans. Yeasts are unicellular microscopic fungi, derived from all the three different groups of fungi but mostly Ascomycetes, and reproducing mostly asexually by budding. However, yeasts reproduce sexually by forming asci / ascospores or basidia / basidiospores. They ferment carbohydrate to ethanol and carbon dioxide. They are non-hyphal.

Q 45. Name sexual and asexual spores of ascomycetes.
Ans. Sexual spores are ascospores while asexual spores are conidia.

Q 46. What are mycorrhizae?
Ans. Mycorrhizae are mutualistic association between certain fungi and roots of vascular plants. The fungal hyphae dramatically increase the amount of soil contact and the total surface area for absorption and help in the direct absorption of phosphorus, zinc, copper and other nutrients from the soil into the roots. Such plants show better growth than those without this association. The plant, on the other hand, supplies organic carbon to fungal hyphae.

Q 47. By what means can individuals in imperfect fungi be classified?
Ans. Individuals in imperfect fungi can be classified on the basis of DNA sequence, though sexual structures may not be found.

Q 48. Give a single characteristic that differentiates Zygomycota from Basidiomycota.
Ans. In Zygomycota, non-septate, multinucleate hyphae are present while in Basidiomycota, septate dikaryotic hyphae are found.

Q 49. State two paralleled characteristic of ascomycete and Basidiomycetes.
Ans.(i) Their sexual spores are called ascopsores.
(ii) Nuclear fusion in the basidium is followed by meiosis.

Written By: Asad Hussain

4 comments:

  1. Really proved very helpful for me

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  2. Please!
    Add all notes of fsc part 01 (biology)
    I'll be very grateful to you sir!
    Regarding maliznah Malik

    ReplyDelete
    Replies
    1. You can find short questions of other chapters by visiting the sitemap.

      Delete
  3. Most satisfied notes for me Allah bless you sir

    ReplyDelete