2.3 Adaptations for Transport in Plants

Question 1

Transport in plants occurs on three levels:
CELLULAR UPTAKE

Answer 1

Question 2

Transport in plants occurs on three levels:
. TISSUE TRANSPORT – SHORT DISTANCE

Answer 2

Question 3

Transport in plants occurs on three levels:
WHOLE PLANT TRANSPORT – LONG DISTANCE

Answer 3

Question 4

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Question 5

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Question 6

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Question 7

Adaptations of root hairs to increase absorption include:

Answer 7

thin cellulose cell wall on root hair extension so the distance for transport is short

large numbers of root hairs each with a long and thin extension into soil to increase the surface area for absorption

large number of mitochondria to produce ATP for active transport of ions.

Question 8

Water can be absorbed in two ways in roots:

Answer 8

it can be absorbed passively into the cell wall which acts as a sponge

it can move into the cell cytoplasm through osmosis.

Question 9

Ions can be absorbed in roots:

Answer 9

passively with water into the cell wall

by active transport into the cell cytoplasm.

Question 10

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Question 11

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Question 12

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Question 13

Answer 13

Question 14

Xylem

A number of different cell types are found in xylem:

Answer 14

tissue that transports water and ions from the roots to the rest of the plant.

Question 15

xylem

Answer 15

Question 16

🌊 Structure of Xylem Tissue

Answer 16

Tracheids and xylem vessels are made of dead cells and have no cell contents.

Their walls contain lignin, which is impermeable to water.

Water enters and leaves xylem vessels through pits (holes in the walls).

Question 17

🌱 Development of Lignin in Xylem

Answer 17

Lignin fibres form differently in:

Protoxylem (young xylem)

Metaxylem (older xylem)

Question 18

Answer 18

Question 19

🌾 Structure and Function of Phloem

Answer 19

Phloem is the tissue that transports organic molecules to the tissues of a plant.

All cells in phloem are alive.

Question 20

Phloem
🧪 Sieve Tube Elements

Answer 20

Question 21

Phloem
⚡ Companion Cells

Answer 21

Question 22

Companion cells and sieve tube link

Answer 22

Companion cells and sieve tube elements are connected via plasmodesmata.

Question 23

phloem

Answer 23

Question 24

🧬 Phloem Sieve Plates

Answer 24

Question 25

phloem

Answer 25

Question 26

phloem

Answer 26

Question 27

Vascular bundles contain

Answer 27

both xylem and phloem together with cambium and other cells.

Question 28

Cambium

Answer 28

is a meristematic tissue; the cells can keep on dividing by mitosis. The cells then differentiate to form the other cells found in the vascular bundle.

Question 29

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Question 30

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Question 31

Answer 31

Question 32

Water moves across the cortex of the root to the endodermis by THREE routes. APOPLAST ROUTE

Answer 32

NOTE: As water moves across the root, water can move between these pathways.

Question 33

Water moves across the cortex of the root to the endodermis by THREE routes. SYMPLAST ROUTE

Answer 33

NOTE: As water moves across the root, water can move between these pathways.

Question 34

Water moves across the cortex of the root to the endodermis by THREE routes. VACUOLAR ROUTE

Answer 34

NOTE: As water moves across the root, water can move between these pathways.

Question 35

Answer 35

Question 36

Ions are absorbed by

Answer 36

a combination of active transport and co-transport as shown in the diagram.

Question 37

mineral ion absorption

Answer 37

Question 38

🔒Apoplast route Ion Movement at the Endodermis

Answer 38

Question 39

Symplast route

Answer 39

Question 40

Answer 40

Question 41

Root pressure

Answer 41

can push water up the xylem against gravity.

Question 42

guttation

Answer 42

water that reaches the leaves is often forced out, causing a beading of water upon the leaf tips

Question 43

Root pressure is caused by:

Answer 43

Question 44

water properties summary

Answer 44

Question 45

transpiration stream

Answer 45

Question 46

transpiration stream diagram

Answer 46

The cohesion-tension theory is the main theory used to explain water movement in xylem.

Question 47

Not all the water absorbed through the roots is lost through the leaves:

Answer 47

Question 48

wilting

Answer 48

If water loss exceeds water uptake, plants will wilt as the leaves and stems lose turgor pressure. The conditions that favour wilting are hot, sunny and windy days.

Question 49

four main factors that affect the rate of water uptake in plants:

Answer 49

Question 50

Answer 50

Question 51

Proving that water is lost from leaves:

Answer 51

Question 52

Measuring water loss:

Answer 52

Question 53

Measuring water uptake:

Answer 53

The rate of water uptake can be determined using a potometer.

Question 54

photometer equations

Answer 54

Question 55

Answer 55

Question 56

Estimating the area of the leaves can be done in two ways.

Answer 56

Question 57

Mesophytes

Answer 57

are plants that live in habitats where there is sufficient water available for their survival.

Question 58

Hydrophytes

Answer 58

are plants that live in or on water and have a plentiful supply of water at all times

Question 59

Xerophytes

Answer 59

are plants that live in areas of low water availability, e.g. deserts, sand dunes, tundra (frozen soil).

Question 60

Adaptations to reduce transpiration loss in plants growing in dry conditions (xerophytes) include:

Answer 60

Question 61

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Question 62

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Question 63

Hydrophytes

Answer 63

are plants that have adapted to living in water – they have different adaptations to xerophytes as water is plentiful.

Question 64

hydrophytes problems they face

Answer 64

Question 65

Adaptations of hydrophytes include:

Answer 65

Question 66

Translocation

Answer 66

is the process of moving the products of photosynthesis from where they are made or stored to other parts of the plant. in phloem

Question 67

Mass flow hypothesis

Answer 67

explain transport in phloem as shown in the diagram.

Question 68

Mass flow hypothesis DAYTIME

Answer 68

Question 69

Mass flow hypothesis Night

Answer 69

Question 70

Mass flow hypothesis diagram of xylem and phloem

Answer 70

Question 71

Mass flow hypothesis Evidence against mass flow

Answer 71

Question 72

Mass flow hypothesis Alternative Theories

Answer 72

Question 73

life cycle of a potato

Answer 73

Question 74

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Question 75

Investigating translocation ringing diagram

Answer 75

Question 76

It was concluded from ringing experiments that:

Answer 76

Question 77

Investigating translocation Use of radio-isotopes

Answer 77

A more sophisticated experiment involved exposing leaves to radioactive CO2 containing the radioactive 14C isotope of carbon as their only external source of CO2. Sugars and other substances made as a result of photosynthesis would then be radioactive. When photographic or X-ray film is exposed to radiation it becomes exposed.

Question 78

Investigating translocation Use of radio-isotopes Diagram

Answer 78

Question 79

Investigating translocation Use of radio-isotopes

Answer 79

When sections of the stem are examined using chemicals that become black under exposure to radiation, black regions appear in the phloem. The only source of radioactivity was from the 14CO2 therefore the radioactive carbon must now be incorporated into organic chemicals produced via photosynthesis and carried in the phloem.

Question 80

Conclusions from these experiments include: Conclusions from these experiments include:

Answer 80

Question 81

Investigating translocation Use of aphids

Answer 81

Question 82

Investigating translocation Use of aphids Diagram

Answer 82

Answer 83