Transcript sperms Vascular Plants

Kingdom Plantae
An Evolutionary History of Plants
Life on Earth: The First Forests
Complete the information on the
next two slides (also shown on the
handout provided in class) as you
view the film.
From the film, list the order of development of
the members of the plant kingdom.
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Circle the group(s) that exhibit each of the
properties listed below.
a.
Require water for swimming gametes
mosses club mosses ferns cycads conifers angiosperms
b.
Possess a vascular system
mosses club mosses ferns cycads conifers angiosperms
c.
Produce spores
mosses club mosses ferns cycads conifers angiosperms
d.
Produce seeds
mosses club mosses ferns cycads conifers angiosperms
Algae are the Ancestors of Plants
Liverworts
Ancestral
green
alga
Origin of land plants
(about 475 mya)
Hornworts
1
Mosses
Lycophytes (club mosses,
spike mosses, quillworts)
Origin of vascular plants
(about 425 mya)
2
Pterophytes (ferns,
horsetails, whisk ferns)
Gymnosperms
3
Origin of seed plants
(about 360 mya)
Angiosperms
500
450
400
350
Millions of years ago (mya)
300
0
Characteristics of Plants
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Eukaryotic
Multicellular
Autotrophic: photosynthetic
Sexual and asexual reproduction
Cell wall made of cellulose
Usually non-motile except for gametes
Adapted to life on land
Adaptations to Life on Land
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Roots and root-like structures
Conduction vessels
Structural support
Water-proof covering
Pores for gas and water exchange
Mechanisms for dispersal of
reproductive products
Vascular Plants
Non-vascular
Seed Plants
Plants
Liver- Mosses Ferns Gymno- Angioworts
sperms sperms
Evolutionary
Tree
of Major
Plant
Groups
Flowers &
Fruits appear
True vascular tissue
and lignin appear
Ancestral
Algae
Seeds and
pollen appear
Shows
increasing
adaptations
for land
dwelling
Plant Life Cycle: Alternation of Generations
Gametes
form by mitosis
Gametophyte
n
Spores form
by meiosis
Spores
n n n n
n Sperm
Gametes meet
Haploid
n
Egg
& fuse to form
zygote
2n
Spore
Mother
Cell
2n Zygote
Diploid
Sporophyte
2n
2n
Embryo
Evolutionary trend: reduction of gametophyte
Bryophytes: Mosses
• No fluid-conducting vascular system
• Enclosed reproductive structures
• Require moist environments
Sporophyte
(stalk)
Female Gametophyte
(leafy)
Vascular Plants
• Specialized groups of
conducting cells
organized into vessels
• Functions of vessels
– conduct water and
nutrients
– provide support to plant
body with lignin
• Largest group of plants
Vascular Plants:
Ferns
• Seedless
vascular plants
• Tall leafy
Sporophyte
• Gametophyte
requires moist
environment
Archegonia
produce eggs
Antheridia
produce sperm
Gametophyte
Mature
Sporophyte
mitosis,
differentiation,
growth
Young
Sporophyte
mitosis,
differentiation,
growth
fusion
to form
zygote
meiosis
Spore
Case
mitosis,
differentiation,
growth
Egg
growth
Zygote
Mature
Gametophyte
Sperm
Diploid
2n
Haploid
1n
Fern
Life
Cycle
Vascular Plants:
Gymnosperms
• Seed-producing
vascular plants
• Pollinated by wind
• Conifers adapted to
cold, dry climate
– cones to protect seeds
– evergreen
– waterproof needle-like
leaves
– sap does not freeze
Vascular Plants:
Gymnosperms
Coastal Redwood
(Tallest Trees)
Giant Sequoia
(Largest Living Thing)
Two
Uncommon
Gymnosperms
Gingko
Cycad
These plants have
separate sexes,
ie. male and
female plants.
Vascular Plants: Angiosperms
• Seed and fruit-producing
vascular plants
• Broad, waterproof leaves
• Modified leaves = Flower
= reproductive structure
• Many have animal
pollinators; some use wind
• Greatly reduced
gametophyte (pollen grain and
embryo sac with egg)
• Largest number of species
(250,000)
Applying Your Knowledge
1.
2.
3.
4.
Mosses
Ferns
Gymnosperms
Angiosperms
Which group of plants
• Encloses seeds within fruit?
• Does not have a vascular system?
• Protects seeds within a cone?
• Has a vascular system but does not
produce seeds?