1. Plants - Earth's Producers
Gymnosperms & Angiosperms

3. Gymnosperms
Most gymnosperms have
– literally: "naked seeds"
• (no protective fruit/nut)
– needles or scales rather than leaves
– deep-growing root systems
• Cycads (Cycadophyta)
– palm-like trees of tropics/subtropics
• Ginkoes (Ginkgophyta)
– only one species: Ginkgo biloba
• Gnetophytes (Gnetophyta)
– Over 70 species in 3 genera
– trees, shrubs & vines
– found in arid deserts or rain forest
• Conifers (Coniferophyta)
– cone bearing trees, evergreens
– pine, fir, spruce, cedar, juniper, etc.

5. Gymnosperms - Conifers
• Vascular
– deep roots
– woody stems (can be tall)
– waxy scales or needleshaped leaves
• Evergreen (usually)
• Grow in dry, cool climates
• Produce seeds in cones
– male cones produce pollen
– pollen transported by wind
– female cones, once fertilized,
produce seeds

7. Angiosperms - Flowering Plants
• Literaly "seed in a vessel"
– Produce seeds in "fruits"
– fruit, nut, veggie, etc.
– flowers containing ovaries
produce seeds
• Vascular
– roots, stems & leaves
– amazing variety

8. Flower Anatomy
• Flowers are the
reproductive organs
(gametophyte stage) of
angiosperms
– Stamen
• holds pollen (male sex
cells)
– Carpel
• holds ovule (female
sex cell)
– Petals
• attract insects for
pollination
• Pollination occurs when
pollen is transferred to
stigma
– 1st step to fertilization

9. Methods of Pollination
• Bees, flies, butterflies,
hummingbirds
– Feed on nectar & pollen
– Attracted by color & smell
• Wind
– Huge amounts of
pollen form clouds

10. Form & Function of Pollen
• The shape and form of pollen is related to its
method of pollination…
• Insect-pollinated species
have sticky or barbed
pollen grains
• Wind-pollinated species
is lightweight, small and
smooth (corn pollen)

11. Fertilization
• Pollen sends “tubes” down style
to join with ovule(s)
• Fertilized ovule(s) becomes seed
(embryo)
• Ovary becomes fruit
– food source for embryo
• Seeds remain dormant until
germination (when seeds sprout)
– sprout is sporophyte stage of plant

13. Seed Dispersal

14. Two Types of Angiosperm Seeds

15. Monocots
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One seed-leaf
Parallel veins
Mostly herbaceous stems
Petals in multiples of 3
i.e. grass, bamboo

16. Dicots
• Two seed-leaves
• Branching veins
• Woody or herbaceous
stems
• Petals in 4’s or 5’s
• i.e. trees, roses

17. Germination
• Environmental conditions required before a seed
will sprout:
– Temperature
• for adequate
metabolism & growth
– Moisture
• seed will swell & soften
when water is present
– Oxygen
• required for cellular
respiration
– Other factors:
• passage of time,
chilling, light exposure

18. Tropisms
• Tropisms describe any plant growth toward or away from
an external stimulus
– phototropism
• toward light
• into soil (away from light)
– gravitropism
• downward (roots)
• upward - stems
– negative, against gravity
– thigmotropism
• response to touch
– hydrotropism
• movement in response to a concentration gradient
• Plant movement & growth is controlled by hormones
Tropisms Video

19. Plant Hormones
• Hormones are chemicals in plants that affect:
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growth of roots, stems, leaves
seed germination
ripening of fruit
formation of flowers
shedding of leaves
• The hormone auxin
influences the rate
division
meiosis)
of cell
(mitosis &
Hormone Video

20. Vegetative Reproduction
• Asexual reproduction = cloning
– Offspring are genetically identical to parent
• Examples:
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Bulbs, corms
Tubers, rhizomes
Runners
Gemmae
Cuttings