plant transportation Flashcards
two types of tubes
xylem and phloem from vascular bundle
xylem function?
transports water and minterals dissolved in water from roots to the rest of the plant
phloem function?
transports sucrose and amino acids from the leaves to the rest of the plant(translocation)
How is xylem located
long,hollow tube made of dead xylem cells,no end walls between cells,thick strong cell walls strengthened with lignin to support the plant
What is a phloem tissue
living cells linked together to form continuous phloem tissue,only contains a thin layer of cytoplasm,sieve tube plates between cells to allow materials to pass through,companion cells adjacent contain mitochondria to generate energy for active trandsport
what are tree rings
mostly xylem tissue,every year new xylem cells produced from a ring of cells just inside bark
how do plants intake water
absorb water through osmosis at root hair cels,water passes across the root from cortex cell to cortex cell via osmosis till it enters xylem cells
Definition of transpiration
loss of water from the plant through the stomata,water evaporates from the vells of the leaf to the airspaces inside leaf and becomes water vapour,air spaces inbetween spongy mesophyll cell,water vapour difuses out of the stomata when they are open,concentation of water vapour in the atmosphere is lower,hence steeper concentration gradient between the laf and the air,faster rate of transpiration
Factors affecting transpiration
temperature,light intensity,wind speed,humidity.
What is a transpiration pull
when water evaporates from spongy mesophyll cells,the water potential is lowered,water from surrounding cells move in to spongy mesophyll by osmosis and continues until water molecules move out of xylem into leaf cell by osmosis.Movement of water out of xylem causes tension at the top of xylem that connects through plant,since water tends to stick together it pulls the water up the xylem from roots
What is translocation
requires energy and use of active transport.sucrose=glucose+fructose,sucrose chosen as it is less chemically active than glucose,sent to other parts of the plant for use in respiration,converted back to glucose production of other molecues required for cell growth,converted to starch and stored.
translocation definition
transport of materials including sucrose and amino acids in phloem
how is amino acids produced
produced by cells using glucose from photosynthesis and nitrogen ions taken from soil,required for production of proteins and enzymes for formation of new plant cells
Source meaning
where substance is produced.for translocation:photosynthesising cells of leaf.transpiration:soil water
sink meaning
where the substance is used
For translocation – Depends on the needs of the plant 🡪 e.g. root/shoot
tips when the plant is growing rapidly, flowers for reproduction, fruits
and production of seeds
For transpiration – photosynthesizing cells of the leaf
