PLANT DIVISIONS

1
PLANT DIVISIONS
2
Invasion of land

• Stomata
• Cuticle
• Lignin bonds to cell wall cellulose to add
  strength and waterproofing
• Vascular tissue xylem and phloem
• Roots absorb nutrients and water vs. rhizoids of
  moss and holdfasts of algae that dont.
• Seeds dormancy
• Fruit spreading seeds
• Flowers cross pollination

3
Cuticle

• A waxy cuticle covers parts exposed to air to
  prevent dessication. Openings in the cuticle
  (stomata) allow for gas exchange and are
  controlled by the guard cells.

Guard cells
4
Vascular tissue

• Most division (all except bryophytes) have
  vascular tissue of xylem (water and minerals) and
  phloem (nutrients).
• Picture shows vascular tissue in a leaf in a
  bundle known as a vein. These are the lines you
  can see in the leaf.

5
Carbon dioxide

• Plants lowered the levels of carbon dioxide from
  25X current levels to current levels over a
  period of 100 million years as they adapted to
  and spread on land.

6
Cuticle, Dermal tissue, ground tissue, and
vascular tissue
7
Flagellated sperm vs. pollen

• The more primitive plants have flagellated sperm
  that allow them to swim to the egg. This means
  that the mosses, ferns, and other primitive
  plants require water to have fertilization.

Fern sperm
Types of pollen
8
Plant Divisions

• Divisions is used instead of phyla

9
Evolution of plants from green algae

• A certain group of green algae known as the
  charophytes have the following in common with
  plants.
• Chloroplasts of both have thylakoids stacked as
  grana and chlorophyll b and carotene to act as
  accessory pigments for chlorophyll a.
• The of cellulose in both is around 25
• Similar mitosis and cytokinesis mechanisms
• Similar sperm structure for sperm
• DNA evidence backs this up.
• Body of some charophytes is haploid, but
  fertilized egg is retained in the organism and
  grows and then does meiosis clue to how
  alternation of generations started.

10
Plants

• NOTE We use the term Divisions instead of the
  term Phyla when referring to plants.
• Characteristics of plant kingdom members
• Alternation of generations with the diploid
  sporophyte generation dominant except in
  bryophytes

11
Plant Divisions Bryophyta

• MOSSES
• Dominant gametophtye generation (green)
• Also includes liverworts and hornworts
• Need sperm to fertilize egg
• NO vascular tissue limits height of the plant and
  therefore have no true roots, stems, or leaves.
• haploid spores are made by meiosis in the
  sporangium of the sporophyte.

Moss sporophyte
12
Other Bryophytes
Hornwort
Liverworts
13

• Homospory one type of spore
• Heterospory female and male spore.

14
Gametophytes

• Antheridium Archegonium
• Male gametophyte Female gametophyte
• Makes sperm makes egg

15
Pterophyta Ferns

• Homosporous create one spore that is bisexual.
• Vascular tissue but no seeds allows them to get
  taller, but limits them to shady moist areas for
  reproduction.
• Fronds big leaf like arrangement
• Fiddlehead emerging sporophyte
• Sporangium make spores on underside of fronds
  when reproducing.

16
Ferns

• Fiddlehead
• Sporangia on underside of frond
• Fronds
• Bisexual gametophyte

17
Gymnosperms (naked seeds) have no flowers
gingko, cycad, and conifers
18
Coniferophyta

• Redwoods, firs, pines, yews, cypresses
• Naked seeds not enclosed in fruits
• Wind pollination (NEEDS A LOT)
• Seeds, vascular tissue
• No flowers
• Often needles thick with cuticle and small in
  size to limit transpiration.

19
Seed cones vs. pollen cones
Seed cones
seeds
Pollen cones
20
Oldest and largest

• Redwoods (400 feet tall) bristlecone pine
  (4600 years old)

21
Anthophyta

• Flowering plants
• Flower will develop into fruit that is used for
  seed dispersal via wind, water, or animal.
• Pollination can be by wind, bird, bat, insect.
• Most advanced (recent)
• Gametophyte is reduced and within the flower.
• Most diverse grasses to trees

22
Monocot (one cotyledon) vs. Dicot (two
cotyledons) the subdivisions of
anthophyta/angiosperms
23
Monocots

• Often grasses and the relatives of grasses

24
Dicots

• Trees, garden plants

25
Vascular bundles locationMonocot
scatteredDicot ring around the outside
26
2 veination in the leaves

• Parallel veins Netlike veins
• Monocot Dicot

27
3 number of seed parts
28
4Flower parts

• Monocot Dicot
• Petals in multiples of 3 Petals 4 or 5

29
Review Questions

• Which is haploid, spore or gamete?
• Which is made by mitosis, spore or gamete?
• Where is the vascular tissue of a monocot?
• Are ferns homosporous or heterosporous?
• Do bryophytes have roots?
• Do ferns have pollen?
• Do gymnosperms have seeds?
• Where are fern sporangia found?

30
Flower structure reproduction organ of some
plants
31
Parts functions

• Female (carpel/pistil)
• Stigma is sticky top that collects pollen
• Style is connection between stigma and ovary.
• Ovary is where eggs are made in the ovules
• Male (stamen)
• Anther makes the pollen
• Filament holds anther away from female part to
  allow for wind/insect to carry pollen away
• Petals (collectively called corona) attracts
  pollinators
• Sepals (collectively called calyx) protects the
  bud before blooming

32
Monoecious (one house) plant has both male and
female on one plant

• Name the parts
• Dioecious Two houses/ male and female plant
• Complete one flower had both female and male
  while incomplete has only one

33
Prefixes for plants

• Mega and Arche are female
• Micro and Anther are male
• Microgametophyte pollen (becomes sperm)
• Megagametophyte makes eggs
• Atheridium anthers make male gametes
• Archegonium place where eggs are made

34
Double Fertilization

• Generative nucleus becomes two sperm through
  mitosis. First sperm fertilizes egg in the ovule
  and second sperm fertilizes polar nuclei to
  become triploid endosperm. Endosperm will become
  food for seed.

35
Seed and Fruit

• Seed, Develops from the ovules within the
  ovaries Covering (seed coat), food (endosperm),
  embryo
• Allows for dormancy until conditions are right
• Germination triggers massive cell division and
  cellular respiration
• Fruit The ripened ovary becomes the fruit after
  fertilization leading to making of the seeds
  seed dispersal is the goal
• Vegetable part of a plant you eat not a
  biological term

36
Fruit Seed dispersal
37
(No Transcript)
38
Review

• The helicopters of a maple tree are what part of
  the plant?
• What is made by the archegonium?
• What part of the flower catches the pollen?
• What is one gymnosperm other than coniferophyta?
• What part of a flower becomes the fruit?
• What part of the flower becomes the seed?
• What are the two products of double
  fertilization?

39
More review

• How do pine trees get pollen to the female?
• How do apple trees get pollen to the female?
• What division of plants includes the tallest
  trees?
• What is the food of a seed called?
• What is the purpose of the endosperm?
• What group of green algae are the closest
  relatives to plants?
• What does the cuticle prevent?
• What division of plant has no flowers, but does
  have seeds?
• What is true of plants that are heterosporous?