Transport in plants Flashcards
What are metabolic demands of a plant?
Glucose and oxygen, waste, hormones and mineral ions
What is the metabolic demand of glucose and oxygen?
It is made by photosynthesising parts of plant has to be transported to all of the cells
What are the metabolic demands of waste?
Excess oxygen must be removed
What is the metabolic demands of hormones?
Made in one part of plat and needs o be transported to were they act
What is the metabolic demands of mineral ions?
Absorbed by the root and need to be transported to all cells for protein synthesis
What is the surface area of plants?
Leaves have a large SA:V ratio but overall plant does not, so the surface alone wouldn’t be enough to get water and sugar around the plant quickly enough
Why do plants have transport systems?
Plants cannot rely on diffusion alone to supply all the needs of the different areas of the plant
Why do pants need transport systems?
They need very effective systems to move substances up and down the plant
What are dicotyledonous plants?
They have 2 halves of the seed called cotyledons
What are cotyledons?
They store nutrients for seed germination and to makes first leaves
What are types of dicotyledonous plants?
Herbaceous and arborescent
What are herbaceous plants?
They are soft tissue and a short life span as leaves and stem dies down to ground level each year
What are arborescent plants?
They are woody with hard lignified tissues and a long life cycle
What is the transport system in plants?
The vascular system
What is the vascular system made up of?
The xylem and phloem
What is the purpose of the xylem?
To transport water and mineral ions from the soil around the plant
What is the purpose of the phloem?
To transport sugars made by photosynthesis around the plant
How is the xylem and phloem arranged?
In vascular bundles
Where are vascular bundle located in roots ?
In the middle
Why is the vascular bundle in the middle?
To withstand tugging strains as stems and leaves are blown about by the wind tugging on the roots
What are the parts of the root?
Epidermis, root hair, xylem, phloem, endodermis, pericycle, cortex and parenchyma cells
What is the epidermis?
Single layer of cells on outside of root
What is the root hair?
A slender extension of specialised epidermal cells (root hair cell)
Where is the xylem located in root?
In the centre
Where is the phloem located in the root?
Around the xylem
What is the endodermis?
A cylindrical layer of cells which encloses the xylem and phloem
What is the pericycle?
Just beneath the endodermis and is able to decide (meristem cells)
What is the cortex?
Several layers of undifferentiated cells (parenchyma) between endodermis and epidermis which contains air spaces
What are the parenchyma cells?
Packing tissue which provides support with permeable walls to water and dissolved solutes
What does the stem contain similar to the root?
Epidermis, cortex and parenchyma
What is the vascular bundle located in stem?
Around the edge of the stem
Why is the vascular bundle around the edge of the stem?
To give strength and support to the stem
What does the vascular bundle contain in the stems?
Xylem, phloem and cambium
What is the cambium?
Meristematic region between the xylem and phloem in the vascular bundle where cells are dividing to form new xylem and phloem tissue
What is the vascular bundle like in young stems and non woody plants?
They are seperate
What is the vascular tissue like in older woody stems?
Continues vascular tissue
What does the midrib of the leaf?
The main vein containing xylem on top and phloem below
Where are the veins in leaves?
They are many small branching spread through leaf
What is the function of midrib and veins?
To support leaf
