1. Chapter
21 Fungi

2. What are Fungi?
• The way in which Fungi grow from
the ground once led scientists to
classify them as
nonphotosynthetic plants
• However, they are not plants at
all, fungi are very different
• Fungi are eukaryotic heterotrophs
that have cell walls

3. Chitin
• A complex carbohydrate that
makes up the cell walls of fungi

4. Fungi Nutrition
• Remember that heterotrophs depend on
other organisms for food
• Unlike animals, fungi do not ingest their
food
• Instead they digest food outside their
bodies and then absorb it
• Many feed by absorbing nutrients from
decaying matter in the soil (decomposers)
• Others live as parasites, absorbing
nutrients from their hosts

5. Structure and Function of Fungi
• All fungi are multicellular with the
exception of yeast
• Multicellular fungi are composed
of thin filaments called hyphae

6. Structure and Function of Fungi

7. Fungus Structure
• The bodies of multicellular fungi
are composed of many hyphae
tangled together into a thick mass
called a mycelium

8. Fungus Structure

9. Fruiting body
• The reproductive structure
growing from the mycelium in the
soil that you recognize as a
mushroom

10. Fungi reproduction
• Most fungi reproduce both
asexually and sexually

11. Spore
• A reproductive cell that is capable
of growing into a new organism by
mitosis alone
• This is how fungi spread

12. Fungal spore

13. Fungi reproduction
• Sexual reproduction involves two
different mating types (+ and -)
• When two hyphae of opposite
mating types meet, their nuclei
fuse together

14. Types of fungi

15. zygomycetes

16. Sac Fungi

17. Yeast

18. Club Fungi

19. Imperfect fungi

20. Ecology of Fungi
• Fungi have been around since life first
moved onto land
• Paleontologists think that fungi helped
early plants to obtain nutrients from the
ground
• Their early appearance suggests that
fungi may have been essential to plants
successful colonization of the land
• Overtime, fungi have become an important
part of virtually all ecosystems

21. Edible and Inedible
Mushrooms
• Many types of mushrooms are
considered delicious
• Although wild mushrooms are edible,
many are poisonous
• You should never pick or eat
mushrooms in the wild
• Leave mushroom gathering to the
experts

22. All Fungi Are Heterotrophs
• Many are saprobes
• Others are parasites
• Others are symbionts that live in
close and mutually beneficial
association with other species

23. Saprobes
• Organisms that obtain food from
decaying organic matter

24. Carnivorous Fungi
• Pleurotus ostreatus

25. Fungi as Decomposers
• Fungi play an essential role in
maintaining equilibrium in nearly
every ecosystem
• They recycle nutrients by
breaking down the bodies and
wastes of other organisms by
releasing digestive enzymes

26. Fungi as Parasites
• As useful as many fungi are
others can infect both animals
and plants and cause diseases
• Ex.) Wheat rust, athelets foot,
Candida, Cordyceps

27. Cordyceps

28. Symbiotic Relationships
• Some fungi form symbiotic
relationships in which both
partners benefit

29. Lichens
• Symbiotic association between a
fungus and a photosynthetic
organism

32. Lichens
• The algae or cyanobacteria - Carries
out photosynthesis providing the
fungus with food
• The fungus provides the algae or
bacteria with – water and minerals
that it collects and also protects the
delicate algae cell
• Lichens are often the first organisms
to enter barren environments

33. Mycorrhizae
• Symbiotic relationship between plant
roots and fungi
• Fungi allow plants to – absorb more
water and minerals
• Fungi also release enzymes that –
free nutrients into the soil
• Plants provide fungi with – the
products of photosynthesis