Plant Transport (7) Flashcards
Requirements of plants
• CO2
• O2
• organic nutrients
• inorganic ions
• water
When is CO2 needed in plants
During the day
Why is O2 needed in plants
For respiration
Why are organic nutrients required in plants
Some plants that don’t photosynthesise, need to receive their glucose from photosynthetic plants
How are inorganic ions and water transported into the plant
• taken up form soil by the roots
• transported to all parts of plant
Uses of magnesium
• chlorophyll synthesis
• ATP functioning
• enzyme functioning
• signalling ion/regulates carbon fixation
• DNA/RNA synthesis
• stabilises DNA/RNA structure; required in translation
• (matrix of) bone
Uses of nitrate ions
• growth
• to make amine group in amino acids
• to make proteins
• to make DNA
Why do plants need a slower transport system than the mammalian transport system
Energy requirements are much less - due to lower rate of respiration and reduced glucose requirements
Description and function of plant leaves
• thin and flat with a large SA:v ratio
• easy for CO2 and O2 to diffuse into, reaching every plant cell and diffusing easily out of the leaves
(Not transport system for the gases)
How many transport systems do plants have
What are the functions
• 2
• xylem - for carrying water and inorganic ions from roots to leaves
• phloem - for carrying glucose, sucrose, amino acids and other substances made from photosynthesis from leaves to other areas
Functions of xylem tissue in a plant
• vascular tissue that carries dissolved minerals and water up the plant
• structural support
•food storage
Xylem + phloem =
Vascular bundles
Where are vascular bundles found
Dependent on which organ they are in as different organs are under different stresses
Where is the vascular bundle and xylem tissue found in the roots
Centre
- centre core of this is xylem tissue
—> helps roots withstand the pulling strains they are subjected to as the plant transports water upwards and grows
Where is the vascular bundle and xylem tissue found in the stems
Around the outside
- xylem tissue found on the inside
—> to support stem
Where is the vascular bundle and xylem tissues in the leaves
VB forms the midrib and veins and therefore spread from the centre of the leaf in a parallel line
- xylem tissue found on upper side of bundles (closest to upper epidermis)
Function of phloem tissue in plants
• to transport organic compounds, particularly sucrose, from the source
• transport of compounds occurs up and down the plant
What is the bulk of phloem made up of
Sieve tube elements
- main conducting cells and the companion cells
What other cell types if phloem made up of and what are the functions
Parenchyma - storage and strengthening fibres
Location of vascular bundles and phloem tissue in roots
VB - Centre
PT - edges of the centre core
Location of vascular bundle in the stems
VB - Around the outside
PT - outside (closest to epidermis)
What does the vascular bundle form in the leaves
VB -the midrib and veins
- spreads from centre of leaf in a parallel line
Location of phloem tissue in the leaves
Lower side of the bundles (closest to lower epidermis)
