Flashcards in Plant Tissues, Organs And Systems Deck (35):
Epidermal tissues - cover plant
Mesophyll - carries photosynthesis
Xylem & phloem - transport substances around plant
Supports leaves and flowers and transports substances around the plant
Absorbs light for photosynthesis
Takes in water and minerals
Equation for photosynthesis?
CO2 & water given light energy and chlorophyll = oxygen and glucose
Composed of still living cells that transport dissolved foods eg Sugars from leaves to rest of plant (thin walls)
Composed of dead cells that transport water and mineral ions through the plan from roots to leaves (thick walls)
Phloem, combium and xylem
(Part of a transport system)
Grow into new xylem and phloem
Form xylem vessels with a one way flow - outer walls thicken - cells die and become lignified- adjoining walls break down to form continuous tube - rings of lignin in walls
Form phloem tubes - two way flow - living cells - end walls form sieve plates
Xylem cells ?
Dead - strong and made of lignin
Xylem direction of transport?
Up from roots to leaves
Xylem substances transported?
Water & minerals
Phloem cells 2?
Living- have sieve plates
Phloem direction of transport?
Up and down - from where made to rest of plant
Phloem substances transported?
Dissolved foods eg sugars
How do stomata open and close?
Controlled by guard cells - light, water taken by osmosis and become turgid due to rigidness of inner walls - pulled apart opening pose -dark, water loss by osmosis and inner walls move together closing pore - photosynthesis increases in stomata and increases sugar concentration gradient which means there is an osmotic gradient
Loss of water vapour due to stomata open to allow CO2 in plant for photosynthesis but water vapour lost from surface of plant
Water evaporates from surface of leaf, water from xylem is pulled up through plant to replace it, this constant movement from roots to leaves is it
Used to measure transpiration?
Increases, light causes stoma to open and wider stoma allows faster transpiration of water vapour out of leaf
Increases, wind blows water vapour away from stoma, keeping concentration gradient high
Increases, higher temp increases kinetic energy of molecules & makes diffusion, osmosis and evaporation occur faster
Decreases, humid air has more water vapour - less able to accept more water molecules by evaporation
Increases rate of photosynthesis and produces more sugars guard cell becomes turgid and guard cells and stoma are more open to collect CO2 so more water can evaporate out
How's a leaf adapted for transpiration?
-large surface area
-stomata mainly on lower surface -spongy mesophyll cells
-waxy layer waterproof on upper epidermis -prevents water loss
-rounded cells not tightly packed -large SA
-guard cells open & close - control water loss
-arrangement of cells - short diffusion distance
Plant organ system?
Roots stems and leads did transport of substance around plant
Root hair cells?
Adapted for efficient uptake of water by osmosis and uptake of mineral ions by active transport
Movement of food molecules through the phloem
Transports dissolved sugars from leaves (made by photosynthesis) to rest of plant for immediate use or storage.
-used in respiration to release energy
-used in meristems - cells divide for growth
-used to make cellulose cell walls
-stored as starch in stems or roots as starch is insoluble
-moved from storage regions to cells where needed
Tubes composed of elongated cells and cell sap can more from 1 phloem to the next through pores in the end walls