1. Reproduction Part 1 (lecture 15) (Bryophytes & Pteridophytes)
Plants!
Reproduction Part 1 (lecture 15)
(Bryophytes & Pteridophytes)

2. Vegetative Reproduction
Asexual Reproduction involving parts of a plant
Cuttings
Plant develops from stem, root, or leaf fragments
Layering
Formation of root off of a stem
Grafting
Aligning vascular cambium of 2 or more plant parts to join them into one
Tissue Culture
Plant tissue cultivated and grown on nutrient media

3. Vegetative Reproduction
African Violet leaf cutting
Layering (raspberries)
Grafted Tree
V-graft (2 apple varieties)
Plant tissue culture

4. Animal vs. Plant Life Cycle
diploid multicellular individual 2n
diploid multicellular
sporophyte 2n
mitosis
zygote 2n
mitosis
meiosis
fertilization
meiosis
gametes 1n
spores 1n
zygote 2n
fertilization
mitosis
mitosis
haploid unicellular
gametes 1n
haploid multicellular
gametophyte 1n
no multicellular haploid
alternation of generations

5. Alternation of Generations
Alternation of Generations – A life cycle that includes a multicellular diploid form (sporophyte) and a multicellular haploid form (gametophyte)
Gametophyte - multicellular haploid form that mitotically produces haploid gametes that unite and grow into the sporophyte generation
Sporophyte - multicellular diploid form that results from a union of gametes and that meiotically produces haploid spores that grow into the gametophyte generation

6. Alternation of Generations

7. WHY, OH WHY (does bio have to be so freaking confusing!)?
A “best of both worlds” idea
Spore – with spores, only one parent contributes to the genes in the offspring
Beneficial if the parent is in a stable environment because offspring will have all of the genes that are successful in that area
Gametes – both parents contribute genes
Beneficial in a changing environment where different traits may enhance survival of offspring

8. First Land Plants Bryophytes: mosses & liverworts non-vascular
haploid
diploid
Bryophytes: mosses & liverworts
non-vascular
no water transport system
no true roots
swimming sperm
flagellated sperm
lifecycle dominated by haploid gametophyte stage
fuzzy moss plant you are familiar with is haploid
spores for reproduction
haploid cells which sprout to form gametophyte

9. Bryophyte Reproduction
Gametangia (on gametophyte)
produce haploid gametes
Antheridium – produces sperm
Archegonium – produces egg
Resulting zygote grows into a
diploid structure (sporophyte)
In mosses the sporophyte is a stalk
Spores from sporophyte disperse & develop into haploid gametes
Gametophyte Dominant!

10. First Vascular Plants Pteridophytes: ferns vascular swimming sperm
diploid
Pteridophytes: ferns
vascular
water transport system
xylem, phloem, roots, leaves
swimming sperm
flagellated sperm
life cycle dominated by sporophyte stage
leafy fern plant you are familiar with is diploid
fragile independent gametophyte (prothallus)
spores for reproduction
haploid cells which sprout to form gametophyte
haploid

11. Pteridophyte Reproduction
Produce spores that form gametophytes
Sori – sporangia clusters on the underside of fern fronds
Meiosis in sporangia forms spores
Antheridia produce sperm and archegonia produce eggs
Sperm swim to meet eggs (fertilization occurs at female reproductive structure) & diploid sporophyte results
Sporophyte Dominant!

12. Alternation of Generations
Fern gametophyte (1n)
small haploid plant which produces gametes
homospory: male & female on same plant
archegonia
antheridia

13. Fern Reproduction
haploid

14. Alternation of Generations
diploid
produces male & female gametes
archegonia
haploid
antheridia

15. Pop Quiz! 1. The evolution of plants:
a.started in aquatic environments.
b.was marked by the development of specialized tissues such as vascular tissue.
c.led to the development of specialized organs.
d.demonstrated a trend toward radiating into drier environments.
e.all of these

16. Pop Quiz!
2. All but which of the following would be associated with vascular plants?
a.root systems
b.Bryophytes
c.Angiosperms
d.Gymnosperms
e.shoot systems
3. Ferns are more advanced than mosses because mosses lack which structure found in ferns?
a. spores
b. cuticle
c. xylem
d. sporophytes
e. pollen