Plant Parts and their Functions

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1 Plant Parts and their Functions Describe principles of plant science as related to horticulture Compare the anatomical parts and distinguishing characteristics of horticultural plants

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

3 Plant Sciences Applied plant sciences are based on the purposes for which the plants are grown Agronomy Forestry Horticulture

4 Agronomy The science and practice of growing field crops such as cotton, wheat, tobacco, corn and soybeans.

5 Forestry The science and practice of growing, managing and harvesting trees for building materials and other products.

6 Horticulture The science and practice of growing, processing and marketing fruits, vegetables, and ornamental plants

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

8 Leaf Retention Deciduous-loses leaves during the dormant season Evergreen-keeps leaves and remains green year-round

9 Plant Hormones Several types of hormones are used to help plants work more efficiently. Inhibitors cytokinins gibberellias auxins

10 Inhibitors Inhibitors hasten fruit ripening, retain seed germination and stem elongation.

11 Cytokinins Hormones that work with auxins to stimulate cell division.

12 Gibberellias Hormones that stimulate cell elongation, premature flowering, and breaking of dormancy.

13 Auxins Hormones that speed plant growth by stimulating cell enlargement

14 Moisture in Plants Turgid-plant is swollen or filled with moisture Wilted-plant is limp because it does not have enough moisture

15 Plant Parts Leaves Stems Roots Flowers

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

17 Leaves-External

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19 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

20 Leaves-Internal Chloroplasts-small green particles that contain chlorophyll gives leaves their green color necessary for photosynthesis

21 Leaves-Internal

22 Leaves-Internal

23 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

24 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

25 Stems-Internal Phloem Phloem Xylem

26 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

27 Stems-Internal Bark Sapwood Cambium Heartwood

28 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

29 Stems-Internal Monocot Dicot

30 Roots-External Root cap-indicates growth of new cells Root hairs-absorb moisture (water) and minerals Root images from a rice plant

31 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

32 Layers of Roots Fibrous-many branched shallow roots are easier to transplant Tap-long root with few branched ones more difficult to transplant

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34 Flowers

35 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

36 Flowers

37 Parts of the Stamen Filament-short stalk that holds up the anther Anther-a sac-like structure that contains pollen, the male sex cells

38 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

39 Parts of the Pistil Stigma Style Ovary

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43 Complete-vs-Incomplete Complete flowers have both male and female parts Incomplete flowers have only male or female parts

44 What are the functions of these plant parts?

45 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

46 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

47 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

48 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

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