transport in plants Flashcards
describe the functions of the transport systems in plants
transport water, minerals, sucrose
- where it is made to where it is needed
2 reasons why multicellular plants have to have transport systems
- distances too large for diffusion to be effective / transport fast enough
- surface area to volume ratio too small
define herbaceous
plant with no woody tissue
define dicotyledonous
plants with two cotyledons in the seed
define vasucular system
a system of transport vessels in animals or plants
define vascular bundle
the vascular system of herbaceious discots
composed of xylem and phloem tissue
name two types of transport vessels in vascular bundles
xylem and phloem
what is the function of xylem
transports water and minerals and structure
what is the function of phloem
transports sucrose
and amino acids etc.
describe the structure of xylem and explain how it is adapted for its function
dead cells - empty, hollow tubes -> no resistance to water
no end walls between cells -> no resistence for water
cell walls strengthened with lignin -> provide support for the plant
describe the patterns of lignification in xylem and state its function
spirals around the xylem vessels
function: strength and structure
define sieve tube element
element of phloem tissue consisting of a longitudinal row of thin walled elongated cells with holes in their connecting walls whcih food materials pass through
define sieve plates
an area with pores present in the end walls of sieve tube elements
define companion cell
specialised parenchyma cell that helps carry out living functions of sieve-tube elements as they cannot live on their own.
how is the phloem adapted for its function
no organelles, little cytoplasm - room for water and sucrose.
perforated ends to let assimilates through
companion cells have many organelles and mitochondria
