1. Plant Structure, Reproduction, and Development

2. Angiosperms Cotyledons – embryonic leaves Monocot – one embryonic leaf
Dicot – two embryonic leaves
Differences between Monocots & Dicots
Veins are parallel /branched
Vascular bundles complex /ring
Leaves arranged in multiples of 3 /multiples of 4 or 5
Fibrous roots /taproot

3. SEED LEAVES LEAF VEINS STEMS FLOWERS ROOTS MONOCOTS DICOTS
One cotyledon
Main veins
usually parallel
Vascular bundles in complex arrangement
Floral parts usually in multiples of three
Fibrous root system
DICOTS
Two cotyledons
Main veins
usually branched
Vascular bundles arranged in ring
Floral parts usually in multiples of four or five
Taproot usually present
Figure 31.2

4. Angiosperms Most angiosperms are dicots
This group includes shrubs, trees (except conifers), and many of our food crops
Monocots include orchids, bamboos, palms, lilies, and grains and grasses.

5. Plant Body Roots have root hairs – outgrowth of epidermal cells
Root system – anchors the plant into the soil
Roots have root hairs – outgrowth of epidermal cells
Shoot system – part of plant above ground
stems – support leaves and grounded
nodes – points where leaved are attached
leaves – main site of photosynthesis
terminal bud – node at tip of plant; responsible for growth lengthwise; apical dominance (inhibits growth of axillary buds)
axillary buds – located in angles formed by the leaf; usually dormant; causes the plant to become bushy

6. Terminal bud
Blade
Leaf
Flower
Petiole
Axillary bud
Stem
SHOOT SYSTEM
Node
Internode
Taproot
Root hairs
ROOT SYSTEM
Figure 31.3

7. Modified Roots and Shoots
STRAWBERRY PLANT
Modified taproots – sweet potatoes, sugar beets, & carrots/ stores starch
Uses this stored sugar source for active growth and producing flowers and fruit
Modified Stems
runner – horizontal stem
rhizomes – horizontal stem underground
tubers – white potatoes that are at the end of rhizomes that store sugar
Runner
POTATO PLANT
Rhizome
IRIS PLANT
Rhizome
Tuber
Taproot
Root

8. Modified Roots and Shoots
Modified leaves
Grasses have no petioles
Celery have enormous petioles that we eat
Tendrils have coiled tips which aid in climbing
Cactus have spines

9. Plant Tissue Systems Epidermis Vascular System Covers and protects
First line of defense
Cuticle is the waxy substance that helps plants to retain water
Vascular System
xylem/phloem – transports water and nutrients
support

10. Plant Tissue System Ground Tissue System Filling spaces, bulk
Parenchyma, collenchyma, sclerenchyma
Photosynthesis, storage, support

11. Plant Tissue System Roots Epidermis Ground tissue Vascular Bundles
Covers roots
Entrance for water and nutrients
May form root hairs
No cuticle
Ground tissue
Cortex – parenchyma, store food
Endodermis – selective barrier, thin layer of cells decides what passes between vascular tissue and cortex
Vascular Bundles
xylem – spokes of wheel
phloem – fills in wedges between spokes

12. VASCULAR TISSUE SYSTEM
Xylem
Phloem
Epidermis
Cortex
GROUND TISSUE SYSTEM
Endodermis
Figure 31.6B

13. Plant Tissue System Leaf Epidermis Ground Tissue Vascular System
Covered by cuticle
Small pores called stomata
Surrounded by guard cells
Ground Tissue
Mesophyll composed of parenchyma cells and chloroplast
Air located in spaces between cells
Vascular System
Vein – composed of xylem and phloem surrounded by parenchyma cells

14. Figure 31.6D

15. Plant Tissue System Stem Epidermis Ground Tissue Vascular Tissue
Thin layer of cells
Covered by cuticle
Ground Tissue
Dicot - 2 parts / Monocot – 1 part (ground tissue)
Pith – food storage
Cortex – fills spaces
Vascular Tissue
Occurs in vascular bundles
Dicot – ring
Monocot - random

16. Figure 31.6C

17. Plant Cells
Three main differences between animal cells and plants cells are
Cell wall
Central vacuole
chloroplasts
Figure 31.5A

18. Plant Cells Five Major Types of Plant Cells
1. Parenchyma cells – most abundant type
Remain alive at maturity
Primary cell wall (thin)
Function in food storage and photosynthesis
Multisided
2. Collenchyma cells
primary cell wall (thick)
alive at maturity
provide support in plants that are still growing

19. Parenchyma Cells
Primary wall (thin)
Pit
Figure 31.5B

20. Plant Cells 3. Sclerenchyma cells Rigid secondary walls
Hardened with lignin
Found in regions that is not growing
Dead at maturity
Two types of sclerenchyma cells
Fiber – long and slender and occurs in bundles; hemp fibers make rope
Sclereid – stone cell; short, irregular shaped secondary wall; found in nutshells and sead-coats

21. Sclerenchyma Cells Pits Secondary wall Fiber cells Primary wall FIBER
Figure 31.5D

22. Sclerenchyma Cells Sclereids (stone cells) Secondary wall
Sclereid cells
Primary wall
Pits
SCLEREID
Figure 31.5D continued

23. Plant Cells 4. Water-Conducting cells
Rigid, lignin-containing secondary cell walls
Cells are dead at maturity
Hollow in the middle
Functions in support
Two types of water-conducting cells
1. Tracheids – long cells with tapered
ends
2. Vessel Elements – wide, short cells
Pits
Tracheids
Vessel element
Pits
Openings in end wall

24. Plant Cells 5. Food – Conducting cells (sieve tube members)
-arranged end to end
- thin primary walls with no secondary wall
-alive at maturity
-transports sugars and minerals
-sieve plates – located at the ends of the sieve tube members

25. Sieve Tube Members
Sieve plate
Companion cell
Cytoplasm
Primary wall

26. Primary Growth
Indeterminate growth – continue to grow as long as they live
Annuals – wheat, corn, rice
Biennials – beets, carrots
Perennials – trees, shrubs, grasses

27. Primary Growth Apical meristem – lengthwise growth
Root cap – protects apical meristem in roots
Two functions of root apical meristem
Replaces cells of root cap
Produces cells for primary growth

28. Primary Growth Three regions of roots Elongation
Epidermis (outermost)
Cortex (bulk)
Vascular tissue
Elongation
uptake of water
cellulose fibers extend (accordion)
forces roots into soil
Differentiation – caused by master gene; causes unspecialized cells to specialize

29. Vascular cylinder
Cortex
Epidermis
DIFFERENTIATION
Root hair
ELONGATION
Cellulose fibers
CELL DIVISION
Apical meristem region
Root cap
Figure 31.7B

30. Primary Growth
Three Zones
Cell division
Elongation
Differentiation

31. Flower Reproduction
The angiosperm flower is a reproductive shoot consisting of
sepals
petals
stamen
carpels
Anther
Carpel
Stigma
Ovary
Stamen
Ovule
Sepal
Petal
Figure 31.9A

32. Fertilization of an Angiosperm
Formation of a pollen grain
Cells that make pollen grains are located in the anther
Meiosis- four haploid spores that eventually form two haploid cells called a tube cell and a generative cell
Wall forms around the two cells known as a pollen grain
Animals, wind, and water transport pollen grain (male gametophyte)

33. Fertilization of an Angiosperm
Formation of an Egg Cell
Megaspore mother cell – forms 4 haploid megaspores and three degenerate
Surviving megaspore enlarges/ mitotic division
End Result – One large cell with two haploid nuclei and six smaller cells.
One of the six smaller cells is the haploid egg.

35. Pollination
Sugar/enzymes on stigma causes tube cell to grow and form pollen tube
Both cells (generative cell and tube cell) travel to embryo sac
Generative cell forms two sperm cells
One sperm cell fertilizes the nucleus with the polar nuclei (triploid nucleus/3n)

36. Pollination One sperm cell fertilizes egg cell (diploid nucleus/2n)
Triploid forms endosperm/functions to nourish embryo (popcorn)
Flowering plants (double fertilization)
Alternation of generations
Haploid – female gametophytes (ovules/egg), male gametophytes (generative cell/sperm)
Diploid – sporophyte (plant/flower); produces haploid spores by meiosis