Plant Transport: Xylem and Phloem Functions

Xylem

Tissue transporting water and minerals upward.

Phloem

Tissue transporting nutrients downward from leaves.

Root hair cells

Extensions increasing root surface area for absorption.

Osmosis

Water movement from high to low concentration.

Transpirational pool

Negative pressure created by water loss from leaves.

Root pressure

Positive pressure from water absorption in roots.

Cohesion

Water molecules sticking together, aiding transport.

Vascular bundle

Structure containing xylem and phloem in leaves.

Palisade mesophyll

Leaf layer where photosynthesis primarily occurs.

Spongy mesophyll

Leaf layer facilitating gas exchange and water evaporation.

Stomata

Pores on leaves for gas and water exchange.

Transpiration

Loss of water vapor from leaves.

Temperature effect on transpiration

Higher temperatures increase transpiration rate.

Humidity effect on transpiration

Higher humidity decreases transpiration rate.

Translocation

Movement of sucrose and amino acids in phloem.

Source

Region producing nutrients in a plant.

Sink

Region storing or using nutrients in a plant.

Photosynthesis

Process using water and sunlight to create energy.

Endodermis

Inner layer of root cortex regulating water flow.

Water movement in xylem

Similar to liquid movement in a straw.

Leaf water entry

Water enters leaves via vascular bundles.

Nutrient transport

Phloem transports nutrients from leaves to rest of plant.