Transport In Plants

Question 1

3 reasons multicellular plants need transport systems

Answer 1

Metabolic demands
Size
SA:V ratio

Question 2

What are dicotyledonous plants

Answer 2

Make seeds containing 2 cotyledons (organs that act as food stores for the developing embryo plant)

Question 3

What are herbaceous dicots

Answer 3

Soft tissues

Short life cycle

Question 4

What are woody dicots

Answer 4

Hard lignified tissues and long life cycle

Question 5

What is a vascular system

Answer 5

Series of transport vessels running through the stem, roots and leaves

Question 6

What is the vascular system in the dicots

Answer 6

Xylem and phloem arranged into a vascular bundle in the leaves, steam and roots

Question 7

Osmosis

Answer 7

Net movement of water molecules through a partially permeable membrane from a region of high water potential to a region of lower water potential
(Passive)

Question 8

Water potential

Answer 8

The tendency of water molecules to move from one place to another
(0 is highest)

Question 9

Hypotonic

Answer 9

Less solute concentrated

Question 10

Isotonic

Answer 10

Equal amounts of solute and water

Question 11

Hypertonic

Answer 11

More solute concentrated

Question 12

Xylem

Answer 12

Transports water and mineral ions (one way)
Dead cells
Columns of cambium cells
Lignin in walls (support and waterproof)
Bordered pits (water leaves xylem and moves to other cells)
Passive

Question 13

Phloem

Answer 13

Transports food (unidirectional)
Living cells
Companion cells have nucleus and linked by plasmodesmata
Active

Question 14

Vascular bundle

Answer 14

Phloem (outside)
Xylem (inside)
Cambium cell’s (divide)

Question 15

Photosynthesis equation

Answer 15

6CO2 + 6H2O —> C6H12O6 + 6O2

Question 16

Root cells

Answer 16

Microscopic size- penetrate easily
Large SA:V
Thin surface area
Water potential gradient

Question 17

Symplast pathway

Answer 17

Cytoplasm
Water moves via osmosis
Water from soil moved from root hair cell to next cell until xylem reached

Question 18

Apoplast pathway

Answer 18

Cell walls and intercellular spaces
Water movies into xylem and cohesion pulls other molecules
Creates tension

Question 19

Explain the movement of water into xylem

Answer 19

Water moves from roots in apoplast/symplast pathway
Casparin strip (Suberin) makes cells waterproof
Water in A blocked and must join S

Question 20

Cohesion tension theory

Answer 20

Model of water moving from the soil in a continuous stream up the xylem and across the leaf

Question 21

What do cells use water for?

Answer 21

Photosynthesis
Maintaining cell turgidity
Making new cells

Question 22

What abiotic factors affect water loss

Answer 22

Temperature 
Light intensity 
Humidity 
Amount of air movement 
Availability of soil water

Question 23

Transpiration

Answer 23

Evaporation of water vapour from the surfaces of plants

Question 24

What biotic factors affect water loss

Answer 24

Stomatal pore size 
Stomata frequency and distribution 
SA:V 
Thickness of cuticle 
Ability to absorb soil water

Question 25

Xerophytes

Answer 25

Plant that is adapted to live in conditions in which there is a scarcity of water in the environment Cacti

Question 26

Adaptations of xerophytes

Answer 26

``` Reduced no. of stomata/sunken stomata Reduced leaves/leaf loss Hairy/curled leaves Long roots Thick wavy cuticle ```

Question 27

Hydrophytes

Answer 27

Plants growing in water and contain many aerenchyma | Water lily

Question 28

Adaptations of hydrophytes

Answer 28

``` Large/thin leaves Very thin or no waxy cuticle Large air sacs Many always open stomata Large SA ```

Question 29

Translocation

Answer 29

The movement of assimilates

Question 30

Symplast route of translocation

Answer 30

Assimilates move through cytoplasm of mesophyll (Passive)

Question 31

Apoplast route of translocation

Answer 31

Assimilates diffuse through cell wall | Reach companion cells and actively transport across membrane with H+ ions (co transport)

Question 32

Evidence for phloem as tissue for translocation

Answer 32

Swollen after ringing Radioactive tracers Aphids Electron microscopy

Question 33

Pressure flow hypothesis

Answer 33

Movement of sap through phloem

Question 34

What does potometer do

Answer 34

Measures water uptake

Question 35

How does the movement of phloem sap occur

Answer 35

By mass flow from sucrose sources to sucrose sinks

Question 36

Active transport

Answer 36

Movement of particles across a plasma membrane against a concentration gradient

Question 37

what are the gaps in the cell walls between companion cells and sieve tube elements called

Answer 37

plasmodesmata