2. • Biological diversity
simply means the
diversity, or variety, of
plants and animals and
other living things in a
particular area or region
• Also means the number,
or abundance of
different species living
within a particular
region
3. Fungi
• Mostly multicellular but some unicellular.
• Has a cell wall but does NOT make its own food.
• Heterotrophic
• Change dead organic matter into usable nutrients…
Decomposers
• Ex: Bread mold, mildew, yeast, and mushrooms.
4. • Distinguished from other
kingdoms by:
– Nutrition
– Structural
organisation
– Growth
– Reproduction
6. • Fungi use extracellular digestion – when enzymes
are secreted outside of their body to digest food
• Most fungi are multicellular
• Fungal spores develop from hyphae
• Many fungi are symbionts with other organisms
7. Absorptive nutrition enables fungi to live as decomposers
and symbionts
• Fungi are heterotrophs that acquire nutrients by
absorption
• Secrete hydrolytic enzymes and acids to decompose
complex molecules into simpler ones that can be
absorbed
• Specialised into three main types:
– Saprobes - absorb nutrients from dead organic
material
– Parasitic fungi - absorb nutrients from cells of living
hosts; some are pathogenic
– Mutualistic fungi - absorb nutrients from a host, but
reciprocate to benefit the host
8. Extensive surface area and rapid growth adapt fungi
for absorptive nutrition
• Basic structural unit of
fungal vegetative body
(mycelium) is the hypha
– Composed of tubular
walls containing chitin
– Provide enormous
surface area: 10cm2
of soil may contain
1km of hyphae with
314cm2 surface area
9. Fungi are adapted to absorb their food from the
environment.
Plants Both Fungi
Autotrophic
(photosynthesize)
Eukaryotic Heterotrophic (absorb
and digest from the
surface they live on for
energy)
Roots Non-motile/ anchored in
soil or structure
Decomposers
1 nucleus per cell Organelles Can have 1+ nuclei per
cell
Cell wall made of
cellulose
Cell Wall Cell wall made of chitin
(carb)
10.
11. 3 Major Features
1.Cell walls
– Made of Chitin
– The same stuff that makes insects’ exoskeleton.
12. 2. Hyphae
• Thin filaments making up the fungus.
• Long, thread-like chains of cells.
• Grow at the tips and branch…
• Mycelium – mass of hyphae
13. Fungal hyphae may be septate or aseptate
• Hyphae of septate
fungi are divided into
cells by crosswalls
called septa
• Hyphae of aseptate
fungi lack cross walls
(coenocytic)
• Parasitic fungi have
modified hyphae
called haustoria,
which penetrate the
host tissue but
remain outside cell
membrane
15. Fungi come in many shapes and sizes.
• Primitive fungi are aquatic and have flagellated spores.
16. Fungi reproduce by releasing spores that
are produced either sexually or asexually
• Usually unicellular, haploid and of various shapes and
sizes
• Produced either sexually (by meiosis) or asexually (by
mitosis)
– In favourable conditions, fungi generally clone
themselves by producing enormous numbers of spores
asexually
– For many fungi, sexual reproduction only occurs as a
contingency- results in greater genetic diversity
• Spores are the agent of dispersal responsible for
geographic distribution of fungi:
– Carried by wind or water
– Germinate in moist places with appropriate substrata
18. 5 Phyla of Fungi
1. Chytridiomycota - Chytrids
2. Zygomycota – Common Molds
3. Ascomycota – Sac Fungi
4. Basidiomycota – Club Fungi
5. Deuteromycota – Imperfect Fungi
19. 1. Phylum Chytridiomycota
• Mostly marine
• Mostly saprophytes (lives on dead
or decaying organic matter)
• Have flagellated spores
20. 2. Phylum Zygomycota
• Mostly terrestrial.
• Two types of hyphae:
– Stolons – (horizontal) spread across the surface
– Rhizoids – (vertical) digs into the surface
21. 3. Phylum Ascomycota (Sac Fungi)
• Most are multicellular (except for
yeast)
• Most undergo asexual
reproduction
• Largest phylum of Fungi
ascoscarpMorels
22. • Club fungi have fruiting bodies which are club-shaped.
• Most are edible
• reproductive structures called basidia
• Include mushrooms, puffballs, and shelf fungi
4. Phylum Basidiomycota (Club Fungi)
23. 5. Phylum Deuteromycota
Ringworm
•Asexual Reproduction
•Imperfect Fungi
•Do not fit into the commonly established taxonomic classification
•No sexual structures
•Multicellular tissue is similar to the hyphae of sac fungi and club
fungi
•Erect hyphae with asexual spores similar to sac fungi and club
fungi
24.
25. – life cycles may include either sexual or asexual
reproduction or both
• Multicellular fungi have complex reproductive cycles.
28. Fungi may be decomposers, pathogens, or mutualists.
• Fungi and bacteria are the main decomposers in any
ecosystem.
– decompose dead leaves, twigs, logs, and animals
– return nutrients to the soil
– can damage fruit trees and wooden structures
29. Fungi can act as pathogens.
• human diseases include ringworm and athlete’s foot
• plant diseases include Dutch elm disease
• Haustoria – hyphae that penetrate the host so that the
parasitic fungus can absorb nutrients
30. • Fungi can act as mutualists.
– lichens form between fungi and algae
– mycorrhizae form between fungi and plants
32. dispersal
fragment (cells of
mycobiont and of
photobiont)
cortex (outer
layer of
mycobiont)
photobionts
medulla (inner
layer of loosley
woven hyphae)
cortex
Crustose