1. Plant Cells, Tissues and Organs

2. Cell Specialization & Cell Differentiation
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookplantanat.html
http://earthsky.org/human-world/nate-lewis-on-artificialphotosynthesis
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookplantanat.html
http://www-plb.ucdavis.edu/labs/rost/tomato/Roots/rootcell.html

3. Specialized Cells & Tissues in Plants
Tissue: group of specialized cells
 Organ: Group of several types of
tissues working towards a specific
function
 Meristem: unspecialized cell that can
form specialized cells in plants


4. Tissues in Plants

5. Repairing & Replacing Specialized
Cells

Buds: Swelling of the
stem
◦ Terminal Bud – most
active growth, produce
Auxin
◦ Lateral Bud – dormant
regions, inhibited by
Auxin

6. Plant Organs
Leaf
 Stem
 Root
 Flower


7. The Leaf
Dermal tissue
 Palisade tissue
 Mesophyll tissue
 Vascular bundles


8. The Leaf – Tissues

Dermal tissue
◦ Waxy cuticle – limits water loss
◦ Protects the leaf

Palisade tissue
◦ Prime site of photosynthesis – palisade cells and chloroplast

Mesophyll tissue
◦ Loosely packed cells
◦ Spaces contain gases such as H2O, CO2 and O2

Vascular tissue
◦ Xylem – transports water to the photosynthesizing cells
◦ Phloem – transports sugar throughout the plant
◦ Small vein branches – every cell gets water and nutrients

9. The Leaf – Lower epidermis


Exchange of gases
Guard cells
◦ Control opening and closing of stomata

Stomata
◦ Connected to spongy mesophyll
◦ CO2 enters, O2 and H2O exits through them

Transpiration – evaporation of water from leaves

10. Chloroplast

11. The Stem
Provides physical
support and transports
sap
 Composed mainly of
xylem tissue

◦ Dead tubular hollow
cells fortified with lignin

Vascular bundle
◦ Phloem (living porous
cells) exchanges
materials with
neighbouring cells

12. The Roots

Anchor a plant to the
ground

Allow water and
minerals uptake from
the soil

Some also act as
plant’s storage area

13. The Roots

Dermal tissue
◦ Root hair – increase
surface area for
absorption

Ground tissue
◦ Cortex – provide
support
◦ Pericycle – vascular
tissue

14. Types of Roots
Tap root
• Allows plant to
reach far
underground for
water
• Anchors the plant
Fibrous root
•
Large surface area
to absorb water
•
Stabilize soil
•
Prevent erosion &
landslides

15. Plants Under Attack

16. The Flower
Reproduction - pollen and
eggs
 Pollination: transfer of pollen
to female parts of flower
 Seeds are produced and
embedded in fruits
 Hormone called ethylene
stimulates ripening of fruits


17. Homework 

P. 69 # 1, 3, 5 - 7