- What are saprophytic fungi?
Ans: These fungi get their food from dead organic matter. They secretes enzyme in their substratum. These enzymes break the organic matter into simple compounds. Then fungi absorb these substances.
- Give occurrence of fungi.
Ans l Fungi are found in wide variety of habitats. These habitats are water, soil, dead and decaying organic matter. Fungi are heterotrophic. They cannot synthesize their food. Therefore, they get their food from different sources.
- What are hyphae and mycelium?
Ans: Hyphae are minute, thread like tubular structure. The group or mass of hyphae is called mycelium. Each hypha has cell mall. In lower fungi cellulose is the chief component. But cell walls of higher fungi have chitin in their cell wall.
- What are Sporophore and Plectenchyma
Aim: Sometimes, hyphae organized to form fruiting bodies. “1–
fruiting bodies are called sporophores. The tissues comp
of compact mass of hyphae are called plectenchyma.
- What are Prosenchyma and Pseudoparenchyma?
Ans: The tissues with distinct hyphae are called prosench. The tissue in which individual hyphae loose their slit ,- and become isodiametric is called pseudoparenchyma.
- What are Stromata and Rhizomorphs?
Ans: Some fungal tissues become very hard. Fruiting bo.
formed on such tissues. These tissues are called several hypae unites to form rope like strand called rhizomorphs. Rhizomorphs form fruiting bodies.
- What is Sclerotium? What is its use
Ans: A mass of hard fungal tissues without fructifications are called sclerotium. Sclerotiums are formed for passing over unfavourable periods. These structures germinate to form new mycelium in favourable conditions.
- How do vegetative reproduction in fungi?
Ans: A mall part of hyphae of fungi can produce complete mycelium. In some fungi fruiting bodies can form new mycelium. Sometimes, some parts of the fungi decompose. The remaining part develops new mycelium.
- Differentiate between spore and conidia.
Ans The spores produced inside the sporangia are called
endospores. The spores produced. at the tip of hyphae outside the sporangia are called conidia. Conidia are produced on special hypha called conidiophores.
10. Differentiate between Arthrospores or oida and
Ans: In some fungi, the hyphae break up into individual cells.
These cells behave as spores. Such spores are called arthrospores or oidia. Sometimes, individual cell:; of the hypae become thick walled. These cells behave as spores. Such spores are called chlamydospores.
11. What is Spermatization?
1ns: In some fungi antheridia are not formed. The fungi develop conidia like spermatia. Spermatia unite with the sex organ or vegetative hyphae of female. Plasmogamy occurs. Thus dikaryotic hyphae are produced.
12. What are conjugate divisions and dikaryotic hyphae?
In the higher fungi karyogamy does not talc: place immediately after fertilization. The oogonium form.; special hyphae. Each cell of this hypha contains two nuclei. Both nuclei divide at the same time. This type of division is known as conjugate division. Such hyphae are called dikaryotic hyphae.
13. How Krankheitsherd form in Plasmodiophora?
The infected host cells grow to form a giant cell. It divides to form daughter cells. Plasmodiophora also divides with host
cells. Thus each cell gets new Plasmodiophora. This process repeated. Thus group of infected cells are formed. This group of infected cells is called Krankheitsherds. it spread infection to large number of cells.
14. How is planogametes forined in Plasmodiophora?
The protoplast of plasmodium splits into many pieces in host cells. Each piece has one haploid nucleus. Each protoplast is surrounded by a thin colourless wall and develops, into gametangium. The nucleus divides mitotically and eight nuclei are formed. The protoplast of gametangium divides into fragments. Each fragment gets one ‘lucid. Each fragment become spindle shaped and develops flagella. Now these are called planogametes.
15. What is Pythium? Which disease does it cause?
Ans! It is common in soil water. Its various species live as saprophyte. Some of them live on decaying plant as parasites. The parasitic stage attacks the roots and the seedlings. It causes disease Damping-off. Pythium deburyanum causes this disease. Some species are parasitic on some freshwater algae.
16. Gis. occurrence and importance of Penicillium.
Ans: Penicillium is a common mold. It is found on different substrata. It is most commonly found on citrus and other fruits. It is also found on foodstuffs, jellies, old leather, and paper and in the soil. Pencillium is used for the r.roduction of certain acids like fumaric, citric, oxalic, and r ilk acids. It is also used in the production of cheese. Fir, antibiotic was obtained from Penicillium notatum.
17. How is Cleistothecium formed in Penicillium?
Ans: The mature ascogonium divides into a number of biaucleate cells. Each cell gives rise to one or. more ascogenous hyphae. A sterile hyphae grows from the mycelium. It encloses the sex organs to form peridium. Thus a characteristic rounded fruit body cleistothecium is formed.
18. What is Haplo-diplobiontic cycle in yeasts?
Ans: In this case, two distinct phases are present during liCe cycle.Thea., phas‘s div ilaplophase and diplophase. Both reproduce by budding. Two haploid cells fuse to form diploid cells. The diploid cell undergoes meiosis and form haploid cells.
19. Name spores produced by Puccinia during its life cycle.
Ans: Uredospore, teleutospores, Basidiospores, Pycnidiospores and aeciospores.
20. Differentiate between primary and secondary gills.
Ans: The gills which run through the whole length of the pileus from stipe to margin of pileus are called primary gill. The gills which do not run along the length of pileus ale called secondary gills.
21. Name some plant diseases caused by fungi.
Ans: Rust, Smut, Powdery mildew, Ergot of rye Red rots of sugar cane. Potato wilt, Cotton root rot , Apple scab and Brown rot.
22. Give symptoms of downy mildew.
Any: The early symptom of the disease is the appearance of small greenish yellow oily spots on the dorsal surface of the leaves. The spots gradually increase in size. They ruse and become brown. The sporangiophores of downy mildew appear on the lower surface of the leaves. The infected leaves dry up. They become brittle and fall off. The disease spreads to other parts of the plant. The berries show brown patches with downy growth. Their colour turns to grayish brown or dark-brown.
23. What are lichens? Give their components.
Ans: The intimate symbiotic association of fungi and algae is called lichens. Algae get protection and get moisture from the fungus. Fungi get nutrition from the algae. T he food substances diffuse from algae to fungi. The algae of lichens mostly belong to Chlorophyta and cyanobacteria.
24. What is upper cortex of Physcia?
Ans: It is present at the upper regions. It is composed o’ closely
packed hyphae. Spaces are absent between them. If spaces are present, they are filled by gelatinous material. The upper surface may be smooth or it has hair like structures. These hairs are formed by scattered hyphae above the cortex.