Mr. Chapman
Biology 20
Fungi Have a Number of
Reproductive Strategies

Depending on the favorability of conditions,
fungi will reproduce either sexually or
asexually.

During favourable conditions, fungi reproduce
asexually. During non-favourable conditions,
fungi will lean towards sexual reproduction.

We will focus on two main groups (phyla) of
fungi and their life cycles: Club Fungi and
Bread Molds.
Something to Think About...
A Quick Note: Single-Celled Fungi

Single-celled fungi, including some yeasts,
reproduce sexually and asexually. There are
two forms of asexual reproduction for
single-celled fungi: Fission and Budding
Yeah, we’ve all seen them... But have you eaten them?
Characteristics of Bread Molds

Form the molds you see on old, spoiled foods,
such as the sandwiches I used to leave in my
locker for months.

Members of the phylum get food by
decomposing dead or decaying matter.

Asexual reproduction performed by spore
production. Recall that spores are haploid (1n)
gametes.
Reproduction in Bread Molds
Asexual Bread Mold Reproduction

The sporangium bursts and releases spores
(1n) to the surface that the mold is growing on.

The spore produces hyphae (1n) under the
surface of the bread, which develops into a
network of mycelia (1n).

Some hyphae (1n) grow above ground, and
produce new sporangia that eventually release
spores.
Sexual Reproduction of Bread Molds

Gametes (1n) of different mating types form at the
tip of hyphae that are very close to each other
under the surface.

The gametes fuse, forming a diploid zygospore
(2n). This zygospore has a tough, thick outer layer,
and can remain dormant for an extremely long
time.

Later on, the zygote (2n) can produce a
sporangium (1n) by meiosis, which grows into a
new spore producing structure.
These ones, you’ve actually probably eaten...
Characteristics of Club Fungi

Named for their club-shaped reproductive
structures, called basidia, which are found
on the undersides of mushrooms.

Some groups of these fungi cause diseases
in plants.

Club fungi only reproduce sexually.
Reproduction in Club Fungi
Sexual Reproduction in Club Fungi

Haploid nuclei (1n) within the basidia fuse to form diploid
(2n) zygotes.

Zygotes (2n) then undergo meiosis to form haploid
spores (1n), which are then released and dispersed by
the wind.

Upon contact with the ground, the spores grow into
hyphae of opposite mating types, fusing to form a diploid
(2n) mycelium underground.

The mycelium grows a new fruiting body (the
mushroom), and the cycle repeats itself.