Plant Transports

Question 1

What are the properties of Monocots

Answer 1

Single Cotyledon,
Long narrow leaf,
Veins are parallel
Vascular bundles scattered
Flower part in multiples of 3

Question 2

What are the properties of dicots?

Answer 2

Two cotyledons
Broad leaf
Network of veins
Ring of vascular bundles
Flower part in multiples of 5

Question 3

What is the Casparian strip

Answer 3

a water-impermeable, waxy suberin layer,

Question 4

What is the cortex in the plant?

Answer 4

The plant cortex is the tissue layer between the epidermis (outer skin) and the vascular bundles (xylem/phloem) in roots and stems, primarily made of parenchyma cells that store food (like starch in potatoes) or water, provide support, and facilitate gas exchange, with specialized cells like collenchyma for support or aerenchyma for air spaces in aquatic plants

Question 5

What is The stele, or vascular cylinder/bundles

Answer 5

Consists of the pericycle, phloem, cambium and xylem.

Question 6

What is the endodermis?

Answer 6

It is the innermost layer of the cortex. It consists of tightly-packed, modified parenchyma cells.

Question 7

What is the xylem tissue?

Answer 7

it is responsible for transporting water and
dissolved mineral salts to the xylem tissue of the stem and leaves. These cells are strengthened with lignin for support. The pits in the cell walls allow for the lateral movement of water.

Question 8

What is Turgidity in refrence to plant cells

Answer 8

Turgidity, or turgor pressure, refers to the water content of cells and how this lends structural support to the plant. When cells absorb water, the vacuoles fill up and the cytoplasm increases, pushing against the cell membranes, which in turn push against the rigid cell walls. This makes the cells rigid, or turgid.

Question 9

Why is transpiration important for the plant?

Answer 9

Cooling of the plant: the loss of water vapour from the plant cools down the plant when the
weather is very hot.

The transpirational pull: when the plant loses water through transpiration from the leaves, water and mineral salts from the stem and roots moves, or is `pulled’, upwards into the leaves. Water and is therefore taken up from the soil by osmosis and finally exits the plants through the stomata.

Plant structure: young plants or plants without woody stems require water for structural support. Transpiration helps maintain the turgidity in plants.

Question 10

how does the transpiration pull occur?

Answer 10

Results from the evaporation of water from the surfaces of the mesophyll layer in the leaf to the atmosphere, through the stomata.

Question 11

What four parts make up the Phloem?

Answer 11

Phloem fibres
Phloem parenchyma
Sieve tubes
Companion cells

Question 12

What are the two ways water can move through the plant?

Answer 12

Apoplast and Symplast

Question 13

What is apoplast?

Answer 13

Water moving through the cell wall/intracellular fluid, it is quick but doesn’t have much control due to it being simple diffusion

Question 14

What is Symplast?

Answer 14

It is when water moves continuously through the cytoplasm, it is very slow but is controllable.

Question 15

Describe how water moves in and out of the plant.

Answer 15

Water enters the roots via osmosis, then travels through the cells by apoplast or symplast to reach the xylem, then due to cohesion/ the water column being under tension, the water moves up the xylem. Then it enters the leaves where it evaporates and leaves through the stomata.

Question 16

What are Vascular bundles.

Answer 16

Vascular bundle: bundles of tissue containing
both xylem and phloem

Question 17

What is the Vaculoar route?

Answer 17

Water passes through tonoplast and then
through vacuoles of cells

Question 18

What is the Protoxylem?

Answer 18

First xylem to develop behind root and shoot tips; lignin added in rings to allow for growth while still transporting water and maintaining strength

Question 19

Metaxylem?

Answer 19

More mature xylem where the walls are fully lignified

Question 20

What is the Secondary xylem?

Answer 20

Formed from ring of cambium

New secondary xylem formed annually: secondary thickening, tree rings

Question 21

What are Tracheids?

Answer 21

Elongated cells with tapering ends

Not as well adapted as the xylem

Water has to pass between cells from pit to pit

Xylem includes fibres for support and parenchyma as packing

Question 22

How does Humidity effect transpiration

Answer 22

Humidity: increase in humidity reduces water potential gradient between air spaces and atmosphere, rate of transpiration decreases

Question 23

How does wind speed effect transpiration

Answer 23

Wind speed: low wind speed, water vapour
accumulates around stomatal pores, reduces
water potential gradient, rate of transpiration
decreases

Question 24

How does temperature effect transpiration?

Answer 24

Temperature: increasing temperature, increasing KE water molecules, increased diffusion and increase in number of water molecules that can be held in air, rate of transpiration increases

Question 25

How does light effect plant transport

Answer 25

Light: indirect effect due to effect on stomatal opening

Question 26

What is a Hydrophytes?

Answer 26

Hydrophytes: water plants eg water lily

Question 27

What is a Xerophytes?

Answer 27

Live under conditions low water availability eg marram grass

Question 28

What is a Mesophytes?

Answer 28

Live under conditions of adequate water

Question 29

What are the qualities of Hydrophytes

Answer 29

Roots submerged in mud at bottom of pond and have floating leaves eg water lily Little or no lignified support tissues (water supports) Little xylem Little or no cuticle on leaves Stomata on upper surface of leaves Stems and leaves large air spaces Reservoir oxygen and carbon dioxide Aerenchyma is a plant tissue that creates large air spaces, allowing for gas exchange between the roots and the air allowing buoyancy

Question 30

What are the properties of Xerophytes?

Answer 30

deep roots to reach water far underground shallow spreading roots to collect occasional rainfall leaves reduced to spines with minimum surface area for transpiration reduced number of stomata to reduce transpiration rate rolled leaves, leaf hairs and stomata sunk in pits to trap moist air, increasing humidity and slowing diffusion of water vapour from the stomata waxy leaf cuticle which is impermeable to water (preventing evaporation) stomata opening at night and closed at midday when evaporation rate would be highest (reversed stomatal rhythm). storage of water in succulent tissues

Question 31

What is the pericycle?

Answer 31

The pericycle is the outermost layer of the stele, and consists of one or more rows of thin-walled meristematic parenchyma cells. It is in close contact with the xylem and phloem tissues of the root.

Question 32

As Phloem does not have lignin, what components give the phloem structure

Answer 32

Phloem Fibres and Sclereids contain lignin and provide structural support, fibres are long and narrow where as sclereids are different shapes.

Question 33

From what part of the plant do root hair cells go from?

Answer 33

Epidermis of the root/ outer layer

Question 34

What two types of transportation occur in roots?

Answer 34

Osmosis of water Active transport to move ions for photosynthesis

Question 35

What is transpiration?

Answer 35

Loss of water vapor by evaporation through stomata

Question 36

What is the purpose of wilting

Answer 36

When a plant is plasmolyzed, it will wilt, this reduces the surface area of leaves exposed to surrounding environment, decreasing transpiration.

Question 37

What are cotyledons

Answer 37

Organs that act as food stores for developing plant embryos.

Question 38

How is water able to leave the lignified xylem?

Answer 38

Leaves via non lignified pits via the plasma membrane to surrounding cells.

Question 39

What is the role of xylem parenchyma

Answer 39

Found on the outside of the xylem Stored food Contains tannins, causing a bitter taste for any herbivore that eats it.

Question 40

How do we allow for water potential to be lower inside the root

Answer 40

Addition of minerals ions into the root to lower water potential via active transport.

Question 41

What is active loading

Answer 41

Co transport of sucrose.