Biology, Plant Form

Raven Biology 13th Edition, CH 35 Plant Form

Diagram of a Plant Body, The plant body is organized with

roots (anchor and absorb), stems (support and transport), and leaves (photosynthesis)

Synthesis of a Plant Cell Wall, Plant cell walls are synthesized through

deposition of cellulose microfibrils and other matrix materials by the plasma membrane

Meristem Cell Division, Meristems are regions of

active cell division that produce new cells for plant growth and development

Apical and Lateral Meristems, Apical meristems are located at tips of roots and shoots and contribute to

primary growth (length)

Apical and Lateral Meristems, Lateral meristems (vascular and cork cambium) contribute to

secondary growth (width/girth)

Dermal Tissue: Stomata, Stomata are

pores in the dermal tissue surrounded by guard cells that regulate gas exchange and water loss

Root Structure, Roots function in

anchoring the plant, absorbing water and minerals, and often storing carbohydrates

Root Cross Sections, In cross section, roots show

epidermis, cortex, endodermis, and vascular cylinder (stele) with xylem and phloem arranged in characteristic patterns

Root Cross Sections, Monocot and eudicot roots differ in

the arrangement of vascular tissues; monocots often have a pith, eudicots have xylem radiating in arms

Stems, Stems contain the three types of plant tissue

and undergo growth from cell division in apical and lateral meristems

Stems, The shoot apical meristem initiates stem tissue and intermittently produces primordia

which develop into leaves, other shoots, and even flowers

Types of Leaf Arrangement, Leaves can be arranged on stems as

alternate (one leaf per node), opposite (two leaves per node), or whorled (three or more leaves per node)

External Stem Structure: A Woody Twig, A woody twig has structures including

terminal bud, lateral buds, leaf scars, lenticels, and nodes/internodes

Stem Vascular Tissue: Monocot & Eudicot Stems, In monocot stems, vascular bundles are

scattered throughout the ground tissue

Stem Vascular Tissue: Monocot & Eudicot Stems, In eudicot stems, vascular bundles are

arranged in a ring separating cortex from pith

Tree Stump, Tree stumps reveal annual growth rings

which represent secondary growth from vascular cambium; each ring typically represents one year of growth

Modified Stems: Bulb, A bulb is a modified stem with

fleshy leaves that sprout from a knoblike stem with adventitious roots; functions in storage and asexual reproduction

Leaves: Monocot and Eudicot Leaves, Monocot leaves typically have

parallel venation and are often elongated with sheathing bases

Leaves: Monocot and Eudicot Leaves, Eudicot leaves typically have

netted/reticulate venation with a distinct petiole and blade

Simple and Compound Leaves, Simple leaves contain

undivided blades

Simple and Compound Leaves, Compound leaves have

blades that are divided into multiple leaflets

Leaf Epidermis: A Stoma, The stoma consists of

two guard cells surrounding a pore; guard cells regulate opening/closing for gas exchange

Eudicot Leaf Diagram, A eudicot leaf cross section shows

upper and lower epidermis, palisade mesophyll (tightly packed for photosynthesis), spongy mesophyll (loosely packed with air spaces), vascular bundles (veins), and stomata on lower surfac