Fungi

1
Fungi
2
(No Transcript)
3
Characteristics of Fungi

• Fungi are heterotrophs that obtain nutrients by
  absorption
• Fungi secrete powerful enzymes that digest food
  outside of the body
• Fungus then absorbs simpler compounds
• This mode of nutrition is used to classify fungi
  as
• Saprophytic fungi
• Parasitic fungi
• Mutualistic fungi

4

• The vegetative (nutritionally active) body of a
  fungus is composed of thread-like hyphae which
  form a netlike mycelium.
• The walls of the hyphae are primarily composed of
  chitin
• The hyphae are divided by septae
• Fungi reproduce by means of spores that may be
  produced either sexually or asexually

5
Close-up of vegetative sporangium of bread mold
6
Classification of Fungi

• The term division is used instead of phylum just
  as in plant classification
• Classification is based upon
• Type of sporangium
• Presence or absence of septae in hyphae
• Type of sexual reproduction

7
Fungal Taxonomic Groups

• Zygomycota-common molds
• Multinucleate hyphae without septa
• Fusion of hyphae forms zygote
• Basidiomycota-mushrooms, toadstools, puffballs
• Sporangium is club-shaped (basidium)
• Ascomycota-truffels, morels
• Sporangium is sac-like (ascus)

8
Basic structure of the black bread mold, a common
zygomycete
9
A common sac fungus. It is within this structure
that sexual phases occur.
10
(No Transcript)
11
(No Transcript)
12
Poisonous toadstool
13
(No Transcript)
14
Shelf fungi such as these are capable of
digesting lignin, a primary component of woody
cell walls
15
(No Transcript)
16
Mycorrhizae as seen with an electron microscope
17
(No Transcript)
18
This unusual fungus preys upon nematodes
19
(No Transcript)
20
(No Transcript)
21
Structure of a lichen, a mutualistic relationship
between an algal and fungal component
22

• Some slime molds are classified as fungi
  imperfecti. Others are classified as protists

23
Fungi and Man

• Many fungi, such as mushrooms and truffles, are
  edible
• Some are pathogenic, causing diseases such as
  athletes foot, ringworm, vaginal yeast
  infections, and lung infections
• Many, such as smuts, rusts, molds, and mildews
  attack food crops
• Many produce compounds with antibiotic and other
  medicinal properties that are useful to man