transport lab

Transport Tissues in Plants

Xylem and phloem are specialized tissues that move water, minerals, and organic compounds through vascular plants.

Simplest Plants

Lack transport systems; rely on osmosis to move water cell by cell.

Water Potential

Predicts direction of water movement based on solute concentration and pressure.

Pressure Differences

Drive flow through xylem and phloem between source and sink.

Vascular Plants

Include xylem and phloem; found in bryophytes, ferns, gymnosperms, and angiosperms.

Angiosperms

Flowering plants divided into monocots and eudicots.

Monocots Examples

Grasses, grains, lilies, orchids, palms.

Eudicots Examples

Herbs, fruit trees, vegetables, deciduous trees, shrubs.

Seed Leaves

Monocots have one; eudicots have two.

Leaf Vein Pattern

Monocots show parallel veins; eudicots show branching veins.

Flower Parts

Monocots in multiples of 3; eudicots in multiples of 4 or 5.

Lab Objective

Observe xylem and phloem in monocot and eudicot roots, stems, and leaves.

Observation Goal

Identify epidermis, cortex, endodermis, pericycle, xylem, phloem, and pith.

Transpiration Study

Measure how environmental factors affect water loss in leaves.

Monocot Root Structure

Xylem and phloem arranged in a ring around central pith.

Water Potential Gradient

Water moves from soil (higher potential) to root (lower potential).

Monocot Root — Epidermis

Outermost layer protecting root.

Monocot Root — Cortex

Region between epidermis and endodermis storing nutrients.

Monocot Root — Endodermis

Inner boundary regulating water entry to vascular tissue.

Monocot Root — Pericycle

Layer just inside endodermis; gives rise to lateral roots.

Monocot Root — Xylem

Transports water upward; arranged in ring.

Monocot Root — Phloem

Transports sugars; alternates with xylem in ring.

Monocot Root — Pith

Central region of parenchyma cells.

Monocot Stem Structure

Vascular bundles scattered throughout stem cross‑section.

Vascular Bundle Composition

Each bundle contains xylem and phloem surrounded by supportive tissue.

Monocot Stem — Epidermis

Protective outer layer.

Monocot Stem — Cortex

Ground tissue beneath epidermis.

Monocot Stem — Vascular Bundle

Contains xylem and phloem.

Monocot Stem — Xylem

Larger vessels; water transport.

Monocot Stem — Phloem

Smaller cells; sugar transport.

Eudicot Root Structure

Xylem and phloem arranged in star shape.

Xylem Arrangement

Forms star at center.

Phloem Arrangement

Located between arms of xylem star.

Eudicot Root — Epidermis

Outer protective layer.

Eudicot Root — Cortex

Stores starch and nutrients.

Eudicot Root — Endodermis

Regulates water entry.

Eudicot Root — Pericycle

Origin of lateral roots.

Eudicot Root — Xylem

Star‑shaped core for water transport.

Eudicot Root — Phloem

Between xylem arms for sugar transport.

Woody Eudicot Stem Structure

Xylem and phloem arranged in concentric rings.

Growth Pattern

Secondary growth adds new xylem and phloem layers.

Woody Eudicot Stem — Epidermis

Outer protective layer.

Woody Eudicot Stem — Cortex

Ground tissue beneath epidermis.

Woody Eudicot Stem — Phloem

Outer ring transporting sugars.

Woody Eudicot Stem — Xylem

Inner ring transporting water.

Woody Eudicot Stem — Pith

Central region of parenchyma cells.

Eudicot Leaf Structure

Upper and lower epidermis with mesophyll layers and vascular bundles.

Mesophyll Layers

Palisade (dense, elongated) and spongy (loose, airy).

Vascular Bundle

Located between mesophyll layers; xylem above phloem.

Stomata Function

Pores for gas exchange and water loss; controlled by guard cells.

Eudicot Leaf — Upper Epidermis

Protective outer surface.

Eudicot Leaf — Palisade Mesophyll

Elongated cells near upper epidermis; photosynthesis.

Eudicot Leaf — Spongy Mesophyll

Loosely arranged cells near lower epidermis; gas exchange.

Eudicot Leaf — Vascular Bundle

Contains xylem (upper) and phloem (lower).

Eudicot Leaf — Xylem

Transports water upward.

Eudicot Leaf — Phloem

Transports sugars downward.

Eudicot Leaf — Guard Cells

Regulate stomatal opening.

Eudicot Leaf — Stomata

Pores allowing CO₂ entry and water vapor exit.

Transpiration

Water movement through xylem driven by pressure differences and evaporation at leaves.

Stomatal Function

Opening allows CO₂ entry for photosynthesis and increases water vapor loss.

Light Intensity Effect

Increased light triggers guard cells to open stomata, raising transpiration rate.

CO₂ and Water Loss

Higher CO₂ uptake correlates with greater water vapor escape.