Fig' 24CO b, p' 426

1
Gymnosperms
Chapter 24
frequent occurrence in cool-temperate forests
Fig. 24-CO (b), p. 426
2
flowering plants
vascular plants (tracheophytes)
land plants (embryophytes)
seed plants (spermatophytes)
green plants (chlorobionta)
3
Conifers
seed-bearing tracheophytes
Cephalotaxaceae
Podocarpaceae
(5 lineages)
Taxaceae
Cupressaceae
Sciadopityaceae
Araucariaceae
Gnetophytes
Pinaceae
Gnetum
Welwitschia
Progymnosperms (fossil records of intermediate
forms trees with spores ferns with seeds)
Ephedra
Flowering plants
Ginkgo
Cycads
(Seed ferns)
Progymnosperms
(Archaeopteris)
seeds
seedless early tracheophytes
pollen
Monilophytes
wood
Earliest Tracheophytes
4
rays
resin duct
summer-wood
Most gymnosperms are woody trees with extensive
secondary growth from a vascular cambium.
one annual growth ring
spring-wood
wood/secondary xylem
tracheids
(no vessels, except for Gnetophytes)
Fig. 24-6, p. 431
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mitospores
SEEDS
fragments
ASEXUALCYCLES
sporophyte
embryo
seed coat food storage
mitosporangium
mitosis,growth
meiosporangium
zygote
Diploid (2n)
Karyogamy
Meiosis
SEXUAL CYCLE
Haploid (1n)
meiospores
n n cell
mitosis,growth
mitospores
Plasmogamy
Pollen
ASEXUALCYCLES
fragments
gametophyte
gametes
mitosporangium
gametangia
Fig. 12-6, p. 190
6
gymnosperms naked seeds angiosperms
enclosed seeds (in fruits)
about 900 species
dominant land plants about 275,000 species
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naked seeds on cone scales
Fig. 24-2, p. 428
8
flowering plants
vascular plants (tracheophytes)
land plants (embryophytes)
seed plants (spermatophytes)
green plants (chlorobionta)
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10
Life Cycle (Pine)
Female gametophyte develops on the sporophyte
Pollen dispersal does not require water.
Fig. 24-19, p. 439
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Cone development takes two years
Table 24-1, p. 443
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Strobilus cluster of leaf-derived sporophylls
Fig. 24-20, p. 440
13
Cone cluster of bracteate branch-derived woody
scales
Fig. 24-21, p. 441
14
mesophyll
Leaves needles, scales, or blades
phloem xylem
vascular bundle
resin duct
endodermis
guard cells
mesophyll
Leaves adapted to drought
stomatal pore
resin duct
schleren-chyma
Leaves life span from 3 to 30 years
epidermis
Fig. 24-7, p. 432
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pollen tube
integument
archegonium with egg
micropylar chamber
female gametophyte
nucellus
Fig. 24-22, p. 442