1. Ch 23- Roots, Stems, and Leaves
Cells of seed plant are organized into different tissues and organs
Principal organs of seed plants- roots, stems, leaves
Roots- absorb water and dissolved nutrients, anchor plants in ground
Stems- supports, transports, and protects plant
Leaves- broad, flat surfaces where photosynthesis takes place

2. Plant Tissue Systems What are the principal tissues of seed plants?
Dermal, vascular, ground
Dermal tissue- “skin” of plant, outermost layer
Consist of epidermal cells
Cuticle- thick waxy coating that protects against water loss
Trichomes- tiny projections that protects the leaf, gives fuzzy appearance
Root hair cells- provide large amount of surface area, aids in water absorption
Guard cells- regulate water loss and gas exchange on underside of leaves

4. What specialized cells make up vascular tissue
Vascular tissue- plants “bloodstream” that transports water and nutrients throughout plant
What specialized cells make up vascular tissue
Xylem and phloem- made up of networks of hollow connected cells that carry fluids throughout plant
Xylem- made up of tracheids and vessel elements, transfers water throughout plant
Tracheids- long, narrow cells with walls that resist pressure, die when mature
Vessel element- cell that forms part of continuous tube in which water can move, die when mature
Phloem- made up of sieve tube elements and companion cells, transfer nutrients throughout cell
Sieve tube elements- cell that is joined end to end to form sieve tubes
Companion cells- cell that surrounds sieve tube elements

5. What are the functions of the three types of cells?
Ground tissue- cells that lie between dermal and vascular tissue, cell walls vary in thickness
Parenchyma- cell with thin cell wall and large central vacuole
Collenchyma-cell with strong, flexible cell wall, helps support larger plants
Sclerenchyma- cell with extremely thick, rigid cell wall that makes ground tissue tough and strong
What are the functions of the three types of cells?

7. Plant Growth and Meristematic Tissue
Meristems- clusters of tissue, responsible for continuing growth throughout plant’s life
Meristematic tissue- found only in tips of shoots and roots, responsible for plant growth
Apical meristem- group of undifferentiated cells that divide to produce increased length of stems and roots
How does meristematic tissue differ from other plant tissue?
Only plant tissue that produces new cells by mitosis

8. Sec 2- Roots 2 main types of roots- taproots and fibrous roots
Taproot- primary root grows long and thick, secondary root remains small
Mainly in dicots
Carrots, oak trees, dandelions
Fibrous- branch of roots where no single root grows larger than rest
Mainly in monocots
Grasses

10. Root Structure and Growth
Roots contains dermal, vascular, and ground tissue
Root consists of central vascular cylinder surrounded by ground tissue and epidermis
Root hair- tiny projection from epidermis
Cortex- spongy layer of ground tissue just inside epidermis
Endodermis- layer of cells that completely encloses vascular tissue
Vascular cylinder- central region of root that includes vascular tissue
Root cap- tough structure that protects a root as it forces its way through surface
What are the different functions of roots?
Anchor plant in ground, absorb water and nutrients

12. Sec 3- Stems What are the main functions of stems?
Produce leaves, branches, and flowers
Hold leaves up to sunlight, transport substances between roots and leaves
Stems made up of dermal, vascular, and ground tissue
Surrounded by epidermal cells with waxy protective coating
Contains nodes- where leaves are attached, internodes- regions between nodes, and buds- undeveloped tissue that produces new stems and leaves

13. How do monocot and dicot stems differ?
Monocots- vascular bundles are scattered throughout stem
Dicots- vascular bundles arranged in ring
Pith- parenchyma cells inside ring of vascular tissue
How do primary growth and secondary growth occur in stems?
Primary growth- growth that occurs at end of plant, increases plant in length.
Produces by cell division in apical meristem
Takes place in all seed plants
Secondary growth- growth in which stems increase in width
Takes place in lateral meristematic tissue- vascular cambium and cork cambium
Vascular cambium- produces vascular tissues and increases the thickness of stems over time
Cork cambium- produces the outer covering of stems

15. Tree rings indicate weather conditions, and age
Formation of wood
Heartwood- older xylem near center of stem, no longer conducts water, usually darkens with age
Sapwood- surrounds heartwood, active in fluid transport, lighter in color
Tree rings indicate weather conditions, and age
Bark- phloem, cork cambium, and cork
Protects tree

16. Sec 4- Leaves
Leaf structure- ideal for absorbing light and carrying out photosynthesis
Blades- thin, flattened sections of leaves
Petiole- thin stalk that attaches blade to stem
Leaf function- carry out photosynthesis
Mesophyll- tissue that makes up most of leaf, performs most of plant’s photosynthesis
Palisade mesophyll- layer of tall, column shaped mesophyll cells just under epidermis of leaf
Spongy mesophyll- loose tissue beneath the palisade layer of a leaf
Stomata- openings on underside of leaf, allow carbon dioxide and oxygen to diffuse into and out of leaf
Guard cells- controls opening and closing of stomata

19. Transpiration- loss of water through its leaves
How does gas exchange take place in a leaf?
Plants regulate the opening and closing of their stomata to balance water loss with rates of photosynthesis

20. Sec 5- Transport in Plants