FUNGI
➢ The branch of biology deals with the study of fungi is called mycology
➢ More than 10,0000 sp. of fungi are known and 200 sp. are pathogenic
➢ More than 200 sp. are eatable
➢ The fungi are:
• Eukaryote
• Multi-cellular (some unicellular like yeast)
• Hetrotrophs
• Recycler or decomposer
• Play role in C, N, S, P cycle
SIMILARITIES WITH PLANTS:
✓ They do not show locomotion
✓ Have cell wall
✓ Lack centriole
DISSIMILARITIES WITH PLANTS:
✓ They are Hetrotrophs
✓ Cell wall made of chitin
✓ They are decomposer
SIMILARITIES WITH ANIMALS:
✓ They are Hetrotrophs
✓ Have chitin (arthropods have chitin in exoskeleton)
DISSIMILARITIES WITH ANIMALS:
✓ Cell wall present
✓ They are sessile
✓ Lacks centriole
➢ The body of fungi is known as mycelium
➢ Body of fungi consist of long, tubular, filament like structure known as hyphae
➢ It is the structure by which fungi attach with substratum (surface where organic material is present)
➢ Hyphae may be aseptate or coenocytic (no cross wall), septate (having cross wall may contain one nucleus; monokaryotic or two nucleus; dikaryotic)
➢ Fungi may be:
✓ Saprobes (live on dead organic matter) (secrete enzymes to decompose)(special hyphae; rhizoids)
✓ Parasitic (live in host; obligate that need host to grow or facultative that can grow on media; special hyphae tips called haustoria)
✓ Predator (like Pleurotus ostreatus omnivorous fungus prey the nematodes)
✓ Symbiotic (like lichens fungus with photosynthetic partner, mycorrhizae; ecto or endo )
The reproduction is asexual and sexual
Asexual reproduction involves:
• Spores
• Budding
• Fragmentation
• Conidia
➢ Sexual reproduction:
✓ Sexual Spores
• A fungal sexual spore results from sexual reproduction
• It consists of three phases:
1. Plasmogamy.
o A haploid nucleus of a donor cell (+) penetrates the cytoplasm of a recipient cell (-).
2. Karyogamy.
o The (+) and (-) nuclei fuse to form a diploid zygote nucleus.
3. Meiosis.
o The diploid nucleus gives rise to haploid nuclei (sexual spores), some of which may be genetic recombinants.
NUCLEAR MITOSIS
✓ Nuclear envelop doses not break
✓ Mitotic spindle forms in the nucleus
Nuclear membrane constrict b/w two cluster of daughter chromosomes
CLASSIFICATION OF FUNGI:
• IMPORTANCE OF FUNGI:
ECOLOGICAL IMPORTANCE:
➢ They are decomposer and can decompose lignin hence important in food chain & and called recyclers
➢ They also used for bioremediation
➢ They help the growth of plants (mycorrhizae association)(95% have)
ECONOMIC IMPORTANCE:
➢ About 200 sp. of fungi (like mushrooms; e.g. Agaricus sp. morels; e.g. Morchella esculenta , truffles; tuber sp.) are edible
➢ Some fungi are poisonous called toadstools e.g. cap/death angle (Amanita) and jack-O lantern
mushroom
INDUSTRIAL IMPORTANCE:
➢ Some fungi used in making beverages like yeast is used for alcohol and lactic acid production
➢ Some used to make citric acid & soya sauce (Aspergillus sp.)
➢ Some natural dyes obtain by them is used in textile industry
MEDICINAL IMPORTANCE:
➢ Fungi are the source of antibiotics & drugs
➢ E.g. penicillin is obtained by Penicillium notatum
➢ Lovastatin (used for lowering blood cholesterol)
➢ Cyclosporine obtain from a soil fungus (used for prevention of transplant rejection)
➢ Ergotine is used to relieve headache & Griseofulvin used for inhibition of fungal growth
IMPORTANCE IN RESEARCH PROCESS:
➢ Yeast is the best organism that can be used for genetic research
➢ In 1996 it is the first eukaryote whose genomic sequence was completely studied
LOSSES DUE TO FUNGI:
➢ Fungi cause serious plants diseases like powdery mildews, ergot of rye, potato wit etc.
➢ It also cause many disease in animals like ringworm or athlete foot
➢ Candida albicans a yeast cause candidacies (vaginal thrash)
➢ Histoplasmosis is the serious lungs infection caused by the fungal spores
➢ Aspergillus fumigatus cause aspergillosis
➢ Some species of Aspergillus produce the alflatoxins (carcinogenic)
➢ Ergotism is caused by eating bread made from the purple ergot-contaminated rye flour which causes the nervous spasm, convulsion, psychotic delusion even gangrene
