1. Unit 5 – Plant Anatomy, Growth & Function
PLANT BIOLOGY: INTRO
Unit 5 – Plant Anatomy, Growth & Function

2. PLANTS IN OUR SOCIETY
In small groups, brainstorm uses for plants in OUR society.

3. USES FOR PLANTS IN OUR SOCIETY
Fuel (ethanol from corn)
Medicine (aloe vera, med. marijuana)
Tools (wood, toxins in wood to kill fish, weapons)
Food
Construction
Alcohol (potato  vodka; grapes  wine)
To breathe!
Shade
Fragrances
Composting
Narcotics
Clothing (ex. Hemp, cotton)
Dyes, tattoos, henna
Paper
Soaps
Flour, mint, herbs, tea, spices
Make-up, cosmetics, beauty and skin care, jewellery

5. Important Crops in Canada (thousands of tonnes)
Wheat 28, 611
Canola 12, 642
Barley 11, 781
Grain corn 10, 592

6. Food Security

7. Monoculture
One type of plant is grown in place of the natural ecosystem
What are some pros and cons of this approach?

8. Learning Check
Pg 539, Q 1-6

9. Medicinal Uses 25% of prescription medicines contain plant extracts
Rosy periwinkle (vincristine andvinblastine) – childhood leukemia and Hodgkin’s. Survival rates have gone from 20% to 90% with these 2 compounds
Goldenseal – colds and sore gums
Ginseng – immune system function

10. Biofuels
Most biofuels come from corn (ethanol). What are some pros and cons of this method?
Research is being done to get fuel from cellulose and oil from algae
Read Quirks and Quarks on page 542

11. Erosion Control
The paradox of farming: farmers need good soil to farm, yet farming destroys good soil.
2.5 million acres each year are lost to urbanization and soil erosion.
About 1/3 of the country's topsoil has been lost due to urbanization and soil erosion.

12. Medicinal Plants Assignment
Pg 573

13. KINGDOM PLANTAE
Plants evolved about 500 million years ago from simple green algae that lived in the ocean.
All plants are autotrophic and some, like the famous Venus fly-trap, can also be heterotrophic.
All plants are eukaryotic and multicellular.

14. PLANT CELLS
Like animal cells, plant cells contain a nucleus and organelles, but they have two distinguishing features:
Cell wall (made of cellulose, a complex carbohydrate, provides rigid structural support; difficult to digest)
Chloroplast (organelle that conducts photosynthesis)
Animal cells have lysosomes that release the cellular equivalent of digestive enzymes. Why don’t plants need these?

15. PLEASE... CONSIDER THE FOLLOWING:
How can plants stand up straight without a skeleton? 15

16. PLANT DIVERSITY Currently over 350 000 species of plants, including:
Mosses
Ferns
Conifers
Flowering plants
Most plants live on land and can withstand a wide variety of climates. Cacti live in arid, dry areas whereas mosses need to be in moist environments to survive.

18. CLASSIFYING PLANTS
Plants are classified based on the presence or absence of vascular tissue
Vascular tissue can be compared to arteries and veins: a network of specialized cells that allows plants to transport water, minerals and sugar throughout the plant
What would you expect a non-vascular plant, without vessels to transport nutrients and water, to look like?

19. Non-vascular (ex. moss) Vascular (ex. tree, sunflower)
Plants
Non-vascular (ex. moss)
Cannot transport foot or water between plant parts
Transport of fluid is through simple absorption or osmosis
Must live in moist environments; need water for reproduction
Vascular (ex. tree, sunflower)
Contain a vascular system allowing for transportation of nutrients / water throughout the plant

20. WHAT MIGHT VASCULAR PLANTS LOOK LIKE?

21. FUNCTION OF STEMS Support system for plant body
Transport system carries water & nutrients (through vascular tissue!)
Holds leaves & branches upright
Looking at the picture below:
What years had the most rain?
What years experienced the worst drought?

22. FUNCTION OF LEAVES Main photosynthetic organ
Broad, flat surface increases surface area for light absorption
Have systems to prevent water loss
Stomata open in day but close at night or when hot to conserve water
Waxy cuticle on surface
System of gas exchange
Allow CO2 in and O2 out of leaf
Elephant Ear Plant

23. LEAF STRUCTURES Cuticle: waxy layer; covers upper surface
Leaf Cross-Section
Cuticle: waxy layer; covers upper surface
Protects leaf against water loss
Veins: transports water, nutrients and food
Made of xylem and phloem vascular tissue
Mesophyll: contains cells that perform photosynthesis
b/c they contain chloroplasts.
Cuticle
Veins
Mesophyll
Stoma
(Opening)
2 Guard Cells
Surround
each
Stoma

24. LEAF STRUCTURES Guard cells: Cells that open and close the stoma
Conserve water by preventing excess water transpiration
Stomata: openings in leaf’s surface; when open:
GAS EXCHANGE: Allows CO2 in & O2 out of leaf
TRANSPIRATION: Allows excess H2O out of leaf
Guard Cells
Stoma

25. FUNCTION OF ROOTS Anchor & support plant in the ground
Absorb water & minerals
Hold soil in place
Fibrous Roots
Root Hairs

26. STRUCTURE OF ROOTS
Root Hairs
Root Hairs: increase surface area for water & mineral absorption
Meristem: region where new cells are produced
Root Cap: protects tip of growing root
Meristem
Root Cap

27. QUIZ TIME! BEFORE WE CONTINUE… VASCULAR OR NON-VASCULAR?

28. VASCULAR PLANTS http://dendro.cnre.vt.edu/forsite/idtype.htm
Gymnosperms
“Naked seeds” are not enclosed in an ovule (like a pine cone).
Plants are usually evergreens.
Ex. pines, cedars, spruces and firs.
Angiosperms
Mature seed is surrounded by the ovule (think of an apple).
Angiosperms are trees/plants that shed leaves every autumn.
Ex. Oaks, maples and dogwoods are examples of deciduous trees.
Contain a vascular system allowing for transportation of nutrients / water throughout the plant

29. QUIZ TIME! BEFORE WE CONTINUE… GYMNOSPERM OR ANGIOSPERM ?

30. KEY WORDS: PLANT BIOLOGY
Cell wall
Chloroplast
Vascular tissue
Non-vascular tissue
Stomata
Cuticle
Veins
Mesophyll
Chlorplast
Guard cell
Transpiration
Root hair
Meristem
Root cap
Gymnosperm
Angiosperm