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Chapter 13
Plants
13A Plants

Botany- study of plants

Most plants are autotrophic but NOT ALLsome heterotrophic, some parasitic

Not all have chlorophyll! Not all are
green!

All are eukaryotic, all have tissues, some
have organs

All have cell walls of cellulose

All sexually reproduce, many also asexual
as well

12 Phyla grouped into 3 groups based on
Vascular tissue (Y/N) and seeds (Y/N)

Will learn 4 major groups
1. Non-vascular- Phylum Bryophyta- Moss
(and 2 others)
2. Vascular seedless- Phylum PteridophytaFerns (& 3 others)
3. Vascular with seeds uncoveredGymnosperms- Phylum Coniferophyta- Pines
(& 3 others)
4. Vascular with seeds coveredAngiosperms- flowering plants- Phylum
Anthophyta- 2 classes: Monocots & Dicots

Box on 333

Groups based on the # of seasons they
grow in
1. Annuals- sprout, grow, produce flowers
and seeds all in 1 growing season
2. Biennials- sprout and grow in 1 season
but don’t produce flowers and seeds until
the next growing season. Die after 2nd year
3. Perennials- grow year after year, mostly
woody but some herbaceous with thick
underground stems that live even when
above ground stems and leaves die
13A-1

Phylum Bryophyta- Mosses

No vascular (water conducting) tissues

No seeds

Very short <3cm

Rhizoids anchor the
moss (not true roots)

Leafy shoot- leaf like,
one cell layer thick

Alternation of generations

2 stage life cycle

Haploid gametophyte generation
produces the diploid sporophyte
generation which produces the
gametophyte etc.

In moss the dominant generation is
the GAMETOPHYTE (leafy shoot)
1. Male and female leafy
shoots
Male= antheridium makes
sperm
Female = archegonium
makes ovum
2. Water brings sperm to
ovum  fertilization
3. Zygote grows a stalk and
capsule (sporophyte) which
makes spores
4. Spores released
5. Spores grow into a protonema which then forms
leafy shoots and rhizoids (gametophyte)
Liverworts
&
Hornworts

Also non vascular
2. Seedless vascular plants
Main one is fern but also…

Club Mosses and Horsetails
13A-2 Ferns: Phylum Pteridophyta

Leaves called fronds, has vascular tissues but no
woody stems, may be large

Some are epiphytes (grow on other plants but not
parasitic)

Rhizomes – underground stems, produce fronds
(young fronds called fiddleheads)

Fronds produce spores = sori
(collection of sporangia)

Spores germinate  heart-shaped
prothallus (gametophyte)

Archegonium & antheridium make
ovum & sperm

Ovum + Sperm  Zygote (makes
the sporophyte  fronds)

Sporophyte is the dominant
generation
Review of Ferns
 Leaves
called fronds (many types
of shapes)
 Rhizome
 Crosiers
– underground stem
or fiddle heads – young
fronds
 Spores
make heart shaped tiny
plant that makes egg & sperm,
needs water to fertilize, then
grows the fiddle head, etc.

13A-3 Vascular with Seeds
2 Groups: Flowering & Nonflowering

A. Gymnosperm = “Naked seed” not enclosed in fruit (ovary)
 Phylum
 Pollen
Coniferophyta = cone-bearing = pines
cones – near tip of branches
 Seed
cones – female, contain ova
 Wind
brings pollen to seed cones

gametes unite, embryo develops

mature seed released to form new tree