Slide 1: Plant Parts and their Functions 13.00 Describe principles of plant science as related to horticulture 14.00 Compare the anatomical parts and distinguishing characteristics of horticultural plants
Slide 2: Plant Sciences • Biology-the branch of science that deals with both plant and animal organisms and life processes – Zoology-the part of biology that deals with animals – Botany the part of biology that deals with plants
Slide 3: Plant Sciences • Applied plant sciences are based on the purposes for which the plants are grown – Agronomy – Forestry – Horticulture
Slide 4: Agronomy The science and practice of growing field crops such as cotton, wheat, tobacco, corn and soybeans.
Slide 5: Forestry The science and practice of growing, managing and harvesting trees for building materials and other products.
Slide 6: Horticulture The science and practice of growing, processing and marketing fruits, vegetables, and ornamental plants
Slide 7: Life Cycles of Plants • Annual-a plant that completes its life cycle in one year • Biennial-a plant that completes its life cycle in two years • Perennial-a plant that lives more than two years
Slide 8: Leaf Retention • Deciduous-loses leaves during the dormant season • Evergreen-keeps leaves and remains green year-round
Slide 9: Plant Hormones • Several types of hormones are used to help plants work more efficiently. – Inhibitors – cytokinins – gibberellias – auxins
Slide 10: Inhibitors • Inhibitors hasten fruit ripening, retain seed germination and stem elongation.
Slide 11: Cytokinins • Hormones that work with auxins to stimulate cell division.
Slide 12: Gibberellias • Hormones that stimulate cell elongation, premature flowering, and breaking of dormancy.
Slide 13: Auxins • Hormones that speed plant growth by stimulating cell enlargement
Slide 14: Moisture in Plants • Turgid-plant is swollen or filled with moisture • Wilted-plant is limp because it does not have enough moisture
Slide 15: Plant Parts • Leaves • Stems • Roots • Flowers
Slide 16: Leaves-External • Petiole-leaf stalk or part that connects the leaf to the stem • Blade-the large, flat part of the leaf • Midrib-the large center vein • Veins-the structural framework of the leaf • Margin-the edge of the leaf
Slide 17: Leaves-External
Slide 18: Leaves-Internal • Upper and lower epidermis-skin of the leaf that prevents the loss of too much moisture • Stomates-small openings under the leaf for breathing or transpiration • Guard Cells-open and close stomates
Slide 19: Leaves-Internal • Chloroplasts-small green particles that contain chlorophyll – gives leaves their green color – necessary for photosynthesis
Slide 20: Leaves-Internal
Slide 21: Leaves-Internal
Slide 22: Stems-External • Lenticels-breathing pores • Bud scale scars-show where terminal buds have been located • Leaf Scars-show where leaves were attached • Terminal bud-bud on the end of a stem • Axillary or lateral bud-bud on side of stem
Slide 23: Stems-Internal • Xylem-tissue that transports water and nutrients up from the roots to stems and leaves • Phloem-tissue that transports food down from leaves to roots
Slide 24: Stems-Internal Phloem Phloem Xylem
Slide 25: Stems-Internal • Cambium-thin, green, actively growing tissue located between bark and wood and produces all new stem cells • Bark-old inactive phloem • Heartwood-old inactive xylem • Sapwood-new active xylem
Slide 26: Stems-Internal Bark Cambium Sapwood Heartwood
Slide 27: Stems-Internal • Monocota-plant stems have vascular bundles that contain both xylem and phloem in each bundle – examples: corn, grasses • Dicata-plant stems have the phloem layer and xylem layer separated by cambium – example: trees
Slide 28: Stems-Internal Monocot Dicot
Slide 29: Roots-External • Root cap-indicates growth of new cells • Root hairs-absorb moisture (water) and minerals Root images from a rice plant
Slide 30: Roots-Internal • Much like stems in that they have a phloem, cambium, and xylem layer • Phloem-the outer layer that carries food down the root • Xylem-the inner layer that carries water and minerals up to the stem
Slide 31: Layers of Roots • Fibrous-many branched shallow roots – are easier to transplant • Tap-long root with few branched ones – more difficult to transplant
Slide 32: Flowers • Sepals-Green parts that cover and protect flower bud before it opens • Petals-are really leaves that are modified to attract insects for flower pollination, the pretty part that we call flowers • Stamen-male part of the flower • Pistil-female part of the flower
Slide 33: Flowers
Slide 34: Parts of the Stamen • Filament-short stalk that holds up the anther • Anther-a sac-like structure that contains pollen, the male sex cells
Slide 35: Parts of the Pistil • Ovules-the eggs or female sex cells that become seeds if fertilized • Ovary-if fertilized becomes a fruit or seed coat • Style-holds up the stigma and connects it to the ovary • Stigma-sticky part on top of style where insects leave pollen
Slide 36: Parts of the Pistil Stigma Style Ovary
Slide 37: Complete-vs-Incomplete • Complete flowers have both male and female parts • Incomplete flowers have only male or female parts
Slide 38: What are the functions of these plant parts?
Slide 39: Functions of Leaves • Photosynthesis-manufactures food in green plants which is the beginning of the food chain for all living things • Photosynthesis is the process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen
Slide 40: Functions of Stems • Translocation-moves water and minerals from roots up to the leaves and move food from the leaves down to the roots • Supports branches, leaves, flowers, fruits and seeds
Slide 41: Functions of Roots • Absorption-take water and nutrients from the soil and conduct them to the stem • Anchor the plant and hold it upright • Store food for plant use • Asexual reproduction in some plants
Slide 42: Functions of Flowers • Produce seeds used for sexual reproduction • Attract insects for pollination (Pollination is the transfer of pollen from anther to stigma.) • Produce fruit to protect, nourish and carry seeds