Describe the features of dicotyledonous plants (Dicots);
two cotyledons
network of veins = starts at the midrib and spreads outwards, for transport and support
Vascular bundles = arranged in rings
Tap Roots
Flowers in multiples of four or five
Describe the features of monocotyledon plants (Monocots):
One cotyledon
Parallel veins
Vascular bundles = complexly arranged
Fibrous root system
Flowers in multiples of three
Give examples of monocotyledon plants (Monocots):
grass
lilies
orchids
palms
Outline reasons why do plants need transport systems?
To reduce the diffusion distance
Large plants have a small surface area to volume ratio
To ensure all cells receive the nutrients they need and remove waste
To move water and minerals from the roots up to the leaves
To move sugars from the leaves to the rest of the plant
Name three types of tissue found in plants:
Ground
Vascular
Dermal
Name the three organs in plants:
Roots
Stems
Leaves
Name the two vascular tissues in plants:
Xylem
Phloem
Name the two dermal tissues found in plants:
Epidermis
Periderm
Name the three ground tissues found in plants:
Parenchyma
Collenchyma
Schlerenchyma
What are found in vascular bundles?
Phloem
Xylem
Describe the location of vascular bundles, xylem, and phloem in young roots:
Vascular bundles = centre
Xylem = centre
Phloem = between the arms of the x-shaped xylem
Describe the location of vascular bundles, xylem, and phloem in stems:
Vascular bundles = near the outer edge
Xylem = towards the inside
Phloem = towards the outside
Describe the location of vascular bundles, xylem, and phloem in leaves:
Vascular bundles = forms midribs and veins
Xylem = above the phloem
Phloem = below the xylem
Describe the features of the vascular bundles in young roots:
Found at the centre
x-shaped xylem at the centre = provides strength to withstand forces
Phloem = between the arms of the x-shaped xylem
outer layer of endodermis = to supply the xylem vessels with water
The pericycle : an inner layer of meristem cells
Define The Pericycle:
An inner layer of meristem cells in the vascular bundles of roots
Describe the features of vascular bundles in stems:
Found near the outer edge
Xylem vessels are towards the inside = provides support and flexibility
Phloem vessels are towards the outside
Cambium : a layer of meristem cells in between the xylem and phloem = produces new xylem and phloem tissues
Define Cambium:
A layer of meristem cells in between the xylem and phloem in the vascular bundles of stems
Describe the features of vascular bundles in the leaves:
Form the midribs and veins = transport and support
xylem = above the phloem
phloem = below the xylem
By which process through the root hair cell does minerals enter the plant?
Active transport
Name the three pathways water is taken up by through plants:
Apoplast pathway
Symplast pathway
Vacuolar pathway
Give two reasons why water is able to move across the root?
the cellulose cell wall is permeable
there is a difference in water potential between the soil and the root hair cells
The water potential is higher in the soil than inside the root hair cells, due to the dissolved substances in the cell sap
Define The Symplast Pathway:
A method of osmosis where water diffuses across the root hair cells to enter the cytoplasm through the plasma membrane and passes from one cell to the next via plasmodesmata
Define Plasmodesmata:
The gaps in the cell wall which connect the cytoplasm of one cell to the next
Define The Apoplast Pathway:
Where water moves by mass flow across the root hair cell through intercellular spaces between cellulose molecules in the cell wall
Define Casparian Strip:
A waterproof strip surrounding the endodermis of the root.
It blocks the apoplast pathway forcing water through the symplast pathway
Explain how water enters the xylem from the endodermis in roots of plants:
the xylem vessels have a higher water potential than the cytoplasm of the endodermis
∴ via active transport, dissolved substances, such as mineral ions and salts, move into the xylem to lower the water potential
Now the cytoplasm of the endodermis has a higher water potential than the xylem vessels
∴ via osmosis, water moves into the xylem
Root hair cells have a large surface area to increase the rate of absorption
Water is absorbed into the plants through the root hair cell by osmosis
Why is water able to move via osmosis through the cytoplasm of successive cells by the symplast pathway in plants?
Each successive cell has a cytoplasm with lower water potential than the previous
Due to what forces of hydrogen bonding in water allows it to move through the cellulose cell wall in the apoplast pathway?
Cohesive
Name the pathway that is generally the fastest for the uptake of water in plants?
The apoplast pathway
Why is the apoplast pathway generally the fastest way for the uptake of water in plants?
there is little resistance to water in the cellulose cell wall
the cellulose cell wall is permeable
Name the type of pathway?
Blue = symplast pathway
Purple = apoplast pathway
Meristem cells in plants are used to generate new plant tissues.
sieve tube elements become elongated and lose most of their cytoplasm.
Name the different features of a transverse section of a plant stem: