These are heterotrophic eukaryotic organisms. They
use decaying organic material as food and are
therefore called saprophytes. Many of them have
the capacity to become multicellular organisms at
certain stages in their lives. They have cell-walls
made of a tough complex sugar called chitin.
Examples are Yeast and Mushrooms.
Filaments of fungi are
The cell walls contain
The MYCELIUM is a
mat of hyphae visible
to the unaided eye
Some hyphae may
divided by cross
sections called septa
Fungi reproduce in both ways, 1) Sexually and,
Asexual Reproduction- production of various
types of spores
Sporangiophores- upright stalk with an enclosed
sac ( bread mold)
Conidia - upright stalk with no enclosed sac
Fragmentation – hyphae dry out and shatter
releasing individual cells that act like spores
Budding – small offspring.
“plus and minus” mating types
Hyphae of different mating types fuse and give
rise to a specialized structure that produces
spores ( diploid)
Most fungi are haploid throughout most of their
When environmental conditions are favorable,
asexual reproduction occurs rapidly. When
unfavorable conditions stress the organism,
sexual reproduction occurs and the offspring
have an increased like hood that they will be
better suited for the environment.
• They are called Saprophytes, they act as recyclers
of dead organic matter, obtaining food from this
• Hyphal tips release enzymes that eventually
decompose and release organic materials into the
• Saprophytic fungi appear on dead trees, logs, plant
litter such as leaves, and even dead insects and
animals. Examples: "Gem-studded Puffball"
(Lycoperdon perlatum) and "Turkey Tail"(Trametes
• Fungi are important decomposers of dead
animal and plant matter. They break down dead
organic matter into simple compounds that can
be absorbed by the plants around it. During the
process of decomposing matter, fungi returns
carbon dioxide to the atmosphere. Green plants
use the carbon dioxide during photosynthesis to
• Beneficial Effects of Fungi
* Decomposition - nutrient and carbon recycling.
* Biosynthetic factories. Can be used to produce
drugs, antibiotics, alcohol, acids, food (e.g.,
fermented products, mushrooms).
* Model organisms for biochemical and genetic
• Harmful Effects of Fungi
* Destruction of food, lumber, paper, and cloth.
* Animal and human diseases, including allergies.
* Toxins produced by poisonous mushrooms and
within food (e.g., grain, cheese, etc.).
* Plant diseases.
Fungal diseases are called mycoses and those affecting
humans can be divided into four groups based on the
level of penetration into the body tissues:
Superficial mycoses are caused by fungi that grow on
the surface of the skin or hair.
Cutaneous mycoses or dermatomycoses include such
infections as athlete's foot and ringworm, where growth
occurs only in the superficial layers of skin, nails, or hair.
Subcutaneous mycoses penetrate below the skin to
involve the subcutaneous, connective, and bone tissue.
Systemic or deep mycoses are able to infect internal
organs and become widely disseminated throughout the