Slide 1
This fern is exhibiting a homosporous life cycle. This fern produces a single spore type that gives rise to a bisexual gametophyte.
The part of the fern that we think of as the fern - is the sporophyte. On the underside of the leaves are structures known as sporangia that produce the spores via meiosis.
A spore is released from the parent plant when the wind
blows, the rain falls, or an animal brushes against it. That spore
disperses into the environment and grows into a gametophyte.
The gametophyte is bisexual - it has both male and female gamete producing structures on the same gametophyte.
The sperm are flagellated so they must swim to the egg for fertilization to take place. Fertilization produces the diploid zygote which then grows into a new multicellular sporophyte.
Slide 2
This image shows the sporangia - the spore producing structures - on the underside of a fern leaf.
The bottom image is a closeup of a single sporangium with spores forming inside.
These spores will be released from the sporangium and grow into a gametophyte.
Slide 3
The top image shows a gametophyte and the blue circular structures are
archegonia - the egg producing structures at 100 times magnification.
The
gametophyte is independent at this stage - it is not associated with any
sporophyte tissue.
The bottom image shows a gametophyte after
fertilization has taken place and the sporophyte is growing out of the
gametophyte. Eventually the gametophyte will atrophy and wither away and
only the sporophyte will remain.
This remaining sporophyte will produces more spores so the life cycle can continue.