Plants

I believe a leaf of grass is no less than the journey work of the stars
-Walt Whitman (Leaves of Grass)

Campbell and Reece chapters 29 and 30

naive - weeds hard to kill, flowers hard to grow - but seriously, there are organisms in 4 of the 5 kingdoms which are plant-like in some ways

KINGDOM DIVISION

Monera Cyanobacteria (blue-green algae)

(recall, "algae" is a term for aquatic plants)

Protista:
Euglena
Diatoms and Golden algae
Dinoflagellates
Red algae
Brown algae
Green Algae

Fungi - actually any similarity to plants is contrived, "animal-centric point of view"

The plant kingdom Chap. 29

TRANSPARENCY Fig. 29.6
Considerable emphasis will be on reproduction.
Human reproduction is hard enough to understand -- plants reproduction is ridiculous.
Alternation of generations.
This is more than just haploid gametes (sperm and eggs) vs. adult form as in human.
In alternation of generations, each form is multicellular
sporophyte is diploid makes spores
(diploid = 2 copies of each gene)
male and female gametophytes are haploid make sperm egg
(haploid = one copy of each gene)

TRANSPAERNCY from an earlier book (I'll show you the one from this book later), note:
(1) diversity of species in each division or class (Angiosperms are by far most numerous)
(2) that algae (protists) were considered to be plants in that (earlier) book

TRANSPARENCY (Fig. 30.13)
flower:
male part-stamen: anther, filament
female part-carpel: stigma, style, ovary
TRANSPARENCY (another book) - see how pollen grain grows to tube to deliver sperm
that is the gametophyte

Kingdom, Phylum, class
(I won't give all the scientific name)

PLANTS

Transition to land required
(1) O2 -> O3 (ozone) to block UV (ultraviolet light) that damages proteins and DNA
(2) Vascular system (like your circulation) - xylem (for water) and phloen (for sugar)
(3) support
(4) sexual reproduction that does not rely on water

TRANSPARENCY Fig. 29.16
Phylum Bryophytes (transitional land plants, mosses, liverworts)
The "Plant" that you see is gametophyte which is unusual (also seeFig. 29.15 (C))
TRANSPARENCY Fig. 30.1 makes this comparison for moss, fern and flowering plant

Vascular plants (tracheophytes)

Phylum Pteridophytes (seedless)
Primitive Horsetails
Club mosses (carboniferous forests, now small)
TRANSPARENCY Fig. 29.23
Ferns Plant is diploid- sporophyte
makes spore
Fern with sori, clusters of sporangia (also see Fig. 29.24)
Spore makes haploid gametophytes
these are aquatic
these make sperm and eggs
Gametes fuse to zygote
grows to plant (vascular)
Frequently flooded swamp forests in carboniferous create "reducing" (in the chemical sense of the word) conditions, and coal is formed from lots of ferns back then.

Seed plants Chapter 30

Gymnosperms (naked seed = no fruit)
Phyla:
Cycads
Gingkos (male and female plants are separate)
dioecious vs monoecious
Conifers (pine, spruce, fir, hemlock, redwood)
male & female cones
Life cycle TRANSPARENCY Fig. 30.9
adaptations to north
evergreen (except larch, bald cypress) (vs deciduous)
needles with cuticle
biomes - northern

Phylum Anthophyta Angiosperms (flowering plants) fruit
235,000 species (successful)
class - monocotyledons
class - dicotyledons (eudicots, a different term, a clade that is most of the dicots)

seed, plant, flower is diploid sporophyte
TRANSPARENCY Fig. 30.17 stamen: anther filament
carpel: stigma style ovary
male gametophyte (pollen)
female gametophyte
2 sperm, one to egg - zygote
other to polars - 3n endosperm

TRANSPARENCY Fig. 29.1
to summarize, evolution

SLIDES (and hyperlinked pictures)
Asexual reproduction:
(1) snake plant - "mother" (left) and "baby" (right) connected at root
(2) spider plant ("babies" hanging [center, bottom of picture])
and
(3) strawberry
(4) mother-in-law's tongue
(5) maternity plant
Pine - female and male cones
Corn male and female flowers
Impatiens - seed pod
Impatiens - seed pod explodes
(That is how impatiens gets its name. The exploding pod is also seen in the "touch-me-not.")
Marigold
Marigold seeds
My socks after I have taken the "scenic route" - seed dispersal

here is a fun site on carniverous plants

In SLU's biology department, there are several faculty members who specialize (and teach courses) in botany, Drs. Barber, Bernhardt, Leverich and Severson

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this page was last updated 1/17/03