1. Plant Classes and Parts
Basic Plant Science
AFNR-BAS-13: Explain and demonstrate basic plant science principles including plant health, growth and reproduction.

2. Uses of Plants Plants provide for the three basic human needs:
food: fruits, vegetables, grains, nuts, etc.
clothing: cotton, linen, wool, leather (plants feed the animals that grow the wool and leather)
shelter: lumber and other wood products

3. Uses of Plants
direct source: the plant or plant products are used by humans
fruits, nuts, vegetables, cotton
indirect source: humans use the animal and animal products that feed on plants and plant products
beef, leather, chicken, wool

4. Uses of Plants
Plants are also used by humans for ornamental and aesthetic reasons to provide comfort or beauty.
landscaping (flowers, shrubs, trees, turf)
ornamental horticulture and floral design (house plants, cut flowers
forestry and outdoor recreation (wildlife habitat, hiking, hunting)

5. Major Groups of Plants gymnosperms: means “naked seed” in Greek
plants that produce seeds not protected by fruit
examples: pines, firs, spruces, redwoods, ginkgo

6. Major Groups of Plants angiosperms:
in Greek means “covered seed” or “enclosed seed”
plants that flower and produce seeds protected by fruit or pods
examples: apples, peaches, pecans, soybeans

7. Major Groups of Plants
There are two classes of angiosperms with distinct characteristics.
cotyledon: an embryonic leaf which become the seed leaf
monocotyledons (a.k.a. monocots); “mono-” - means “one”
dicotyledons (a.k.a. dicots); “di-” means “two”

8. Major Groups of Plants monocotyledons (a.k.a. monocots)
seeds have one cotyledon therefore the seedlings have one seed leaf
the vascular bundles are scattered
the leaves have parallel veins
flower parts are in multiples of three

9. Major Groups of Plants dicotyledons (a.k.a. dicots)
seeds have two cotyledons therefore the seedlings have two seed leaves
the vascular bundles are arranged in a circle
the leaves have netted veins
flower parts are in multiples of four or five

10. Taxonomy (Naming Plants)
scientific names are in Latin and printed in italics
common names can be confusing because different areas call plants by different names
binomial nomenclature
two-name system
first name is the genus
second name is the species
species can be further subdivided into varieties

11. Plant Life Cycles
Annuals: plants that complete their life cycle in one year (or one season)
examples: marigolds, pansies, petunias, melons, beans, squash (and many other flowers, crops, and weeds)

12. Plant Life Cycles
Biennials: plants that complete their life cycle in two growing seasons
grows vegetative structures (roots, stems, leaves) in the first year and then after a period of dormancy during cold months, it will produce flowers and seeds before dying
examples: carrot, parsley, onion, cabbage, hollyhock, Black-eyed Susan

13. Plant Life Cycles
Perennials: plants that produce for more than two years or growing seasons
may die back during the winter months and then return from their rootstock
examples: azalea, alfalfa, pine trees, maple trees, fruit and nut trees, blueberries
There are two classes of perennials.
herbaceous: plants that have soft stems that are killed by frost
woody: plants with hardy stems that can survive winter frost

14. Plant Processes
photosynthesis: the chemical process converting sunlight into energy and food for the plant
respiration: the process of plants using stored energy
transpiration: the movement and loss of water through evaporation

15. Plant Parts Roots: anchor the plant absorb water and minerals
store manufactured food
primary root: the single main root
secondary roots: small roots that branch off the main root
root hairs: many tiny roots that increase the surface area of the root for absorption
root cap: protects the growing tip of roots

16. Plant Parts Types of Roots:
tap root: root system with one thick main root
fibrous roots: system with many small roots
adventitious roots: grow from the stem or leaf of a plant
example: corn has roots above ground to prop up the stalk

17. Plant Parts Stems: support the leaves, flowers, and fruit
conduct water, minerals, and food
store food and water
produce new stem tissues

18. Plant Parts Two types of conductive tissues in the stem:
xylem: transports water and minerals from the roots
phloem: transports food from the leaves
both are created by the cambium which becomes growth rings in trees
the xylem and phloem are arranged in a ring in dicots and scattered in moncots

19. Plant Parts Leaves: produce food for the plant through photosynthesis
epidermis: protective layer of cells
cuticle: waxy coating that prevents water loss
stomata: pore-like openings on the underside of the leaf that allow gas exchange
guard cells: control the opening and closing of the stomata
mesophyll: where photosynthesis takes place; made up of palisade layer and the spongy layer
veins: contain xylem and phloem and transport water and nutrients

20. Plant Parts
Flowers:
purpose of flowers is to reproduce through the production of seeds
sepals: the outermost part of a flower (usually green) that protects the unopened flower and supports the petals when it blooms
as a whole all the sepals are called the calyx
petals: attract insects and birds for pollination; usually conspicuously colored

21. Plant Parts Flowers: stamen: the male part of the flower
anther: produces the pollen which contains the male sex cells
filament: supports the anther
pistil: the female part of the flower
stigma: provides a sticky surface to catch pollen
style: supports the stigma
ovary: produces the female sex cells and becomes the fruit

22. Flower Anatomy

23. Plant Parts
Flowers:
complete flowers: flowers that have all the parts (sepals, petals, stamen, and pistil)
incomplete flowers: flowers that lack one of the four main parts - petals, sepals, pistil, or stamen
male flowers will not have a pistil and female flowers will lack stamen
monoecious: plants that have male and female flowers on the same plant
dioecious: plants that have male and female flowers on separate plants

24. Plant Parts
Fruit:
a mature (fertilized) ovary containing the seed or seeds
may be fleshy or dried
fleshy fruit are soft and may be consumed by humans or animals as food which helps to disperse the seeds; examples include pumpkin, apple, tomato
dry fruits have hard seeds

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