Units 20 & 21
Seedless Plants
Biology 1407
Collin College
On previous episodes we
learned:
• Haploid – one set of chromosomes
• Diploid – two sets of chromosomes
On previous episodes we
learned:
• Mitosis
– division of the cells nucleus resulting in
two daughter nuclei
On previous episodes we
learned:
• Meiosis
process in which a diploid cell undergoes two
successive nuclear divisions potentially
producing four nuclei
(spores)
On previous episodes we
learned:
• Gametophyte
– gamete producing stage (sex cells, n)
– haploid
• Sporophyte
– spore producing stage (2n)
– diploid
What brings these two teams
together
What brings these two teams
together:
•The basic plant life cycle
What brings these two teams
together
Plants have an alternation of generations
The life cycle of all land plants alternate between
2 generations :
•
Gametophytes and sporophytes
• Each generation giving rise to the next
What brings these two teams
together
• So a plant walks into a bar…………………………
Remember, its a Lifecycle
Today’s challenge:
• Adaptation to life on land!
Today’s challenge
• Team Moss
• Amphibians of the plant kingdom
• Tropics to Arctic
• No vascular tissue
Root-like
Stem-like
Leaf-like
Today’s challenge
Gametophyte phase of Reproduction is dominant.
-What we recognize as the plant
Today’s challenge
• In mosses, the leaf-like gametophyte shoots
bear either antheridia or archegonia, where
gametes are produced
Today’s challenge
• The female gametophyte produces eggs in the archegonia
Today’s challenge
• The male gametophyte produces flagellated
sperm in antheridia
Today’s challenge
• On maturation:
– The sperm swims to the egg and
fertilization occurs(must have water)
Today’s challenge
• After fertilization:
– Meiosis occurs and spores are
produced.
– Spores are spread by the wind.
Today’s challenge
Immunities earned by Team Moss
• Soil formation
– Erosion
• Historical
– WWI
• Commercial
– Peat moss
– Surf boards
Today’s challenge
• Team Fern
• Vascular tissue present
– Phloem and xylem
most important adaptation
– Temperate regions to Arctic Circle
Today’s challenge
Sporophyte phase of reproduction is dominant
- What we recognize as the plant
Today’s challenge
• On the undersurface of the fern’s fronds cells undergo
meiosis to create haploid cells (spores)
Today’s challenge
• The spore develops into a gametophyte that
can produce both sperm and eggs
– Prothallus…The love pad
The love pad…
Today’s challenge
• The sperm and egg unite in the processes called fertilization,
producing a "baby" fern called a zygote
• which now has two copies of each chromosome (it is diploid)
Today’s challenge
• By normal cell division, this grows into the fern as we
know it.
• The fern produces the spore and the cycle continues.
Today’s challenge
• Immunities earned by Team Fern
• Commercial
– Arrangements
• Medical
– Intestinal parasites
• Scientific
– Hunger buster
– Air quality
Recap today’s episode
Team Moss
Gametophyte phase of reproduction
is dominant.
No vascular tissue
Soil formation
– Erosion
Historical
– WWI
Commercial
– Peat moss
Team Fern
Sporophyte phase of reproduction
is dominant.
Vascular tissue present
Commercial
– Arrangements
Medical
– Intestinal parasites
Scientific
– apical meristems
– EPA
The winner of Survivor
Plantae:
TEAM FERN
Today’s vascular plants dominate
the natural landscape in almost all
of the earth’s terrestrial habitats.