Plants Roots Stems Leaves and Flowers Chapter 23

Plants: Roots, Stems, Leaves and Flowers Chapter 23 6/12/2021 SB 3 A and SB 3 C 1

Standard SB 3 A and SB 3 B Students will derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems. A. Explain the cycling of energy through the process of photosynthesis and respiration. B. Compare how structure and function vary between the six kingdoms. 6/12/2021 SB 3 A and SB 3 C 2

Parenchyma Cells n n n 6/12/2021 SB 3 A and SB 3 C Stores starch, oils, and water Heals wounds to plant Thin flexible walls 3

Collenchyma cells n n Provide support growing plants Strong and flexible Ex: Celery strings Unevenly thick cell walls 6/12/2021 SB 3 A and SB 3 C 4

Sclerenchyma cells n n 6/12/2021 SB 3 A and SB 3 C Strongest of the plant cells Second cell wall has lignin Die at maturity Used to make linen and rope 5

Plant Organs n n Roots Stems Leaves Flowers 6/12/2021 SB 3 A and SB 3 C 6

Plant organs composition n Dermal tissue (covers outside of plant) ¡ ¡ ¡ n Ground tissue (inside of plant) ¡ ¡ ¡ n Protects the plant Secretes cuticle Forms outer bark of trees Provides support Stores minerals in roots and stems Common parenchyma cells Vascular tissue (transport system) 6/12/2021 SB 3 A and SB 3 C 7

Roots n Functions: ¡ ¡ Anchors Plant Absorbs water and minerals Stores photosynthetic products Root hairs aid in absorption 6/12/2021 SB 3 A and SB 3 C 8

Roots n Primary Root ¡ n Taproot ¡ ¡ n First root to grow out of the seed Main root Anchors plant Food and water storage Ex: carrot Fibrous Roots ¡ ¡ ¡ Roots that spread out Anchors plant Rapid water storage 6/12/2021 SB 3 A and SB 3 C 9

Root Structure n 3 parts ¡ Apical Meristem n n ¡ Region of Elongation n ¡ New cells grow larger Region of Maturation n 6/12/2021 Place of cell division Root cap over meristem to protect it New cells specialize into the type of cell they will become (ex: xylem, phloem) SB 3 A and SB 3 C 10

Root cap covers the tip. root cap

Apical meristem is an area of growth apical meristem

Vascular cylinder contains xylem and phloem vascular cylinder

Root Structure n Cross Section of Root ¡ Outer surface = Dermal Tissue n ¡ Inner Area = Cortex n ¡ Root hairs found here, absorb water Cells where water/minerals flow through the root to the center Endodermis = Surrounds the innermost area n Controlled by the Casparian Strip ¡ ¡ Vascular Cylinder = Inner most area n 6/12/2021 Semi permeable, controls what gets into the center of the cell Xylem and phloem found here SB 3 A and SB 3 C 14

The Structure of a Root Epidermis Endodermis Root hairs Ground tissue (cortex) Phloem Xylem Vascular Cylinder Ground tissue (cortex) Epidermis Endodermis Vascular cylinder Zone of maturation Zone of elongation Apical meristem Root cap 6/12/2021 Cross Section of Plant Root (magnification: 40 x) SB 3 A and SB 3 C 15

Stems n Function ¡ ¡ Support leaves and flowers Transport n ¡ ¡ Xylem and Phloem Grow underground for storage Grow into new plants 6/12/2021 SB 3 A and SB 3 C 16

Stems n Apical Meristem (primary growth) ¡ ¡ n Found at tips of stems Makes plant grow taller Lateral Meristem (secondary growth) ¡ ¡ Found at sides of stem Makes plant grown in circumference 6/12/2021 SB 3 A and SB 3 C 17

Stems n Modified Stems ¡ Rhizomes n n ¡ Tubers n ¡ Food storage Bulbs n 6/12/2021 Food storage Asexual reproduction Food storage SB 3 A and SB 3 C 18

Stems n Annual Rings ¡ Vascular bundles (bundles of xylem and phloem) in the stem n n ¡ Age trees by counting the rings n 6/12/2021 Spring Time – lots of growth, light colored rings Summer Time – some growth, dark color one light, one dark = 1 year SB 3 A and SB 3 C 19

Tree Rings 6/12/2021 SB 3 A and SB 3 C 20

Leaves n n Purpose: Photosynthesis Many types of leaves ¡ ¡ ¡ n Generally thin and flat Tendrils Spines Types of tissue ¡ ¡ 6/12/2021 Palisade mesophyll absorbs sunlight Spongy mesophyll connects to stomata SB 3 A and SB 3 C 21

The Internal Structure of a Leaf Cuticle Veins Epidermis Palisade mesophyll Xylem Phloem Vein Spongy mesophyll Epidermis Stoma Guard cells 6/12/2021 SB 3 A and SB 3 C 22

Leaves n All leaves have Stomata ¡ Stomata allow for gas exchange n ¡ Close at night and when losing too much water Guard Cells control the opening and closing of the stomata 6/12/2021 SB 3 A and SB 3 C guard cells 23 stoma

Leaf Adaptations n n Extreme temperature (pine needles) Water loss (cactus spines) Aquatic environments (water lilies) Getting food (Venus flytrap) 6/12/2021 SB 3 A and SB 3 C 24

Review n Alternation of generations ¡ SPOROPHYTE PHASE ¡ fertilization meiosis Plants alternate between the two Each cycle divides by mitosis GAMETOPHYTE PHASE 6/12/2021 SB 3 A and SB 3 C 25

Review n Sporophyte diploid phase is ¡ Begins with fertilized egg ¡ Spores produced through meiosis n Gametophyte phase is haploid ¡ ¡ Begins with spore Gametes produced through mitosis 6/12/2021 SB 3 A and SB 3 C 26

Flowers n Purpose: Reproduction ¡ Male Parts: Stamen n n Supports the anther Female Parts: Pistil n stigma carpel style ovary Stigma ¡ n anther Produces pollen Filament ¡ n filament Anther ¡ ¡ stamen Sticky top Style Ovary ¡ 6/12/2021 Produces fruit SB 3 A and SB 3 C 27

Flowers n Examples of Fruits: ¡ ¡ ¡ ¡ 6/12/2021 Grapes Apples Pears Peas Corn Wheat Walnuts Tomatoes Pineapple Pumpkins Watermelons Cherries Cucumbers SB 3 A and SB 3 C 28

The Structure of a Flower Stamen Anther Filament Stigma Style Ovary Petal Ovule 6/12/2021 Carpel Sepal SB 3 A and SB 3 C 29