9.1 Transport in the xylem of plants

transpiration

loss of water vapor from the aerial parts of plants (stems and leaves); occurs as a consequence of gas exchange in the leaf

humidity

amount of water in the air

stomata

tiny openings on the epidermis (surface) of leaves

xylem

vascular tissue that carries water upward from the roots to every part of a plant

guard cells

The two cells that flank the stomata and regulate its opening and closing

xerophytes

plants that live in arid climates

xerophytes

cacti, succulents

halophytes

plants that live in salt marshes or mud flaps (example: glasswort)

potometer

measures transpiration levels

casparian strip

cylinder of cells that are surrounded by a thin strip of wax, forms a barrier between vascular tissues and outer ground tissues

symplast route vs apoplast root

two ways water can travel once it enters the plant

symplast route

water travels through the root inside of cells

plasmodesmata

small gaps in the cell walls of neighboring cells that allow water to pass through seamlessly, helps with the symplast route of water travel

apoplast route

water travels through the cell walls and the intercellular space of the cortex

aquaporins

regulate the rate of water uptake as they are specialized water channels on the root cell membrane