Transport In Plants

Front 1

Types of water in soil

Back 1

Hygroscopic , Combined, Gravitational, Capillary

Front 2

____________ water is held very tightly around soil particles by adhesive forces

Back 2

Hygroscopic

Front 3

Meaning of hygroscopic water

Back 3

water held very tightly around soil particles by adhesive forces

Front 4

Meaning of combined water

Back 4

Water present in form of hydrated oxides of Al,.Si, etc.

Front 5

What is combined water? How much of it available to plants?

Back 5

Hygroscopic and combined. Not available to plants

Front 6

Meaning of gravitational water

Back 6

Due to gravitational force, some amount of water goes beyond through the large pores between soil particles, goes beyond the reach of roots of plants and reaches the water table

Front 7

Which type of water is available to plants?

Back 7

Capillary water

Front 8

What is capillary water?

Back 8

In between small, colloidal soil particles, very small spaces (capillaries) are present. The water in this spaces is known as capillary water available for absorption.

Front 9

Diffusion is obvious in ____________. Give reason-

Back 9

Gases and liquids due to high KE

Front 10

Define Simple Diffusion

Back 10

Movement of ions, atoms, or molecules of solutes, liquids or gases from region of hugher concentration to region of lower concentration till equilibrium is reached.

Front 11

Which of Diffusion, facilitated diffusion and active transport is not dependent on living system?

Back 11

Diffusion

Front 12

In diffusion, particles move in a ____________ fashion.

Back 12

Random

Front 13

Comment on probability of diffusion w.r.t. solids.

Back 13

Diffusion in solids is more likely than diffusion of solids

Front 14

Why is diffusion very very important in plants?

Back 14

It is the only means for gaseous movement within body

Front 15

Factors affecting diffusion rates

Back 15

1. Concentration gradient

2. Permeability of separating membrane

3. Temperature

4. Pressure

5. Size of substances

Front 16

Diffusion pressure is (cause/ result) of diffusion

Back 16

Cause

Front 17

Define diffusion pressure

Back 17

Potential ability of solid liquid or gad to diffuse from an area of its greater concentration to an area of lesser concentration

Front 18

DP proportional to -

Back 18

Number of diffusing molecules

Front 19

Effects of adding solutes to water

Back 19

DP reduces

Front 20

What is DP of pure water?

Back 20

1236 (Maximum)

Front 21

What is facilitated diffusion?

Back 21

Selective transport of large molecules across cell membrane assisted by special proteins (porins) without expenditure of energy

Front 22

Water soluble substances are transported across membranes by ___________ ___________ aquaporins.

Back 22

8 different

Front 23

Diffusion of a substance across cell membrane primarily depends on its _______________.

Back 23

Solubility of lipids

Front 24

Which substances diffuse through cell membrane faster?

Back 24

Fat soluble/ Hydrophobic

Front 25

Which substances find difficult to diffuse through cell membrane ?

Back 25

Substances that have a hydrophilic moeity

Front 26

Porins facilitate diffusion by setting up a concentration gradient - True or False giving reasons

Back 26

False - They do set up a gradient, a gradient should already be present

Front 27

How do porins help in transport?

Back 27

The proteins form channels in the membrane for molecules to pass through. Some channels are always open others can be controlled.

Front 28

Give types of passive transport with meaning

Back 28

Symport - 2 molecules in same direction

Anti port - 2 molecules in Opp. Direction

Uniport - 1 molecule membrane independently

Front 29

Factors increasing active transport

Back 29

Higher rate of respiration - more ATP - more salt accumulation

Front 30

Factors reducing active transport

Back 30

Respiratory inhibitors, Low O2 content

Front 31

What the proteins used for active transport known as?

Back 31

Pumps

Front 32

Transport from lower to higher concentration to lower concentration also known as -

Back 32

Uphill transport

Front 33

Compare diffusion, facilitated diffusion and active transport w.r.t. to above points

Back 33

Front 34

Water has ________________ so it can move up by capillary action.

Back 34

High surface tension

Front 35

Water has ________________ which enables to form a continuos stream of water.

Back 35

High tensile strength

Front 36

Water has high ____________, ____________, ____________, hence it acts as temperature stabilizer.

Back 36

Specific heat, heat of fusion, heat of vaporization

Front 37

Water has high Specific heat, heat of fusion, heat of vaporization so it can act as _____________.

Back 37

Temperature stabilizer

Front 38

In what activities is water required w.r.t. reproduction and gaseous exchange? (4)

Back 38

Movement of gametes, stomatal movements, dehiscence of fruits, germination of seeds

Front 39

How does water help aquatic plants?

Back 39

Transparent, so light passes - photosynthesis

Front 40

Percentage of water in

1. Watermelon

2. Most herbaceous plants

Back 40

1. 92%

2. 10-15% of fresh weight as dry matter

Front 41

Is a seed actually dry? Give reason

Back 41

No, it has water. Otherwise, it wouldn't be alive and respiring

Front 42

Give amount of absorption of water by

1. A mature corn plant

2. Mustard plant

Back 42

1. About 5 L/ day

2. = Body weight / 5 hr

Front 43

Water is a limiting factor for _____________ and ____________ in both ____________ and ___________ environments.

Back 43

Plant growth, productivity, agricultural, natural

Front 44

Examples of membranes

1. Freely Permeable

2. Semi Permeable

3. Selectively Permeable

4. Impermeable

Back 44

1. Cell wall

2. Parchment paper, Egg membrane

3. Cell membrane, tonoplast

4. Suberin in cork and endodermis, cuticle

Front 45

What do the following membranes allow to pass?

1. Freely Permeable

2. Semi Permeable

3. Selectively Permeable

4. Impermeable

Back 45

1. Solvent, solute

2. Solvent

3. Solvent, some selected solutes

4. None

Front 46

Water always goes from _________ to ___________.

Back 46

Hypotonic to hypertonic

Front 47

Concentration of solution is given by _______________. Its unit is ______________.

Back 47

Osmolarity, milliosmoles/litre

Front 48

Formula of osmolarity

Back 48

Moles of solute / volume of solvent in litres

Front 49

Define osmosis

Back 49

Diffusion of water or solvent from a solution of lower concentration to a solution of higher concentration or from pure solvent to solution through semi-permeable membrane

Front 50

Type of surrounding solution for following condition

1. Turgid

2. Flaccid

3. Plasmolysed

Back 50

1. Hypotonic

2. Isotonic

3. Hypertonic

Front 51

What happens when cell is kept in -

1. Hypotonic

2. Hypertonic

3. Isotonic

Back 51

1. Endosmosis - Turgid

2. Exosmosis - Plasmolysed

3. No net flow - Equal in and out - Flaccid

Front 52

In plant cells, the _____________ contributes to solute potential of cell.

Back 52

Vacuolar sap

Front 53

In plant cells, the vacuolar sap contributes to ___________ of cell.

Back 53

solute potential

Front 54

At equilibrium, both cell and surrounding should have same ______________.

Back 54

Water potential

Front 55

Which is the most accepted mechanism used for Translocation of sugar from source to sink? Who put it forward?

Back 55

Pressure/ mass flow hypothesis by E. Munch

Front 56

Process of mass flow hypothesis

Back 56

Glucose - Sucrose - Companion cells - Sieve tube (active transport) - hypertonic - water from xylem - OP increase - decrease at sink - active transport - glucose - energy use - water to xylem

Front 57

Loading of phloem sets up a __________________ that facilitates _______________ in phloem.

Back 57

Water potential gradient, mass movement

Front 58

Which experiment is used to identify the tissues through which food is transported?

Back 58

Girdling

Front 59

What is done in girdling?

Back 59

On the trunk of a tree, ring of bark upto a depth of phloem layer is removed.

Front 60

Girdling shows that _________ is the tissue responsible for Translocation of food and that transport takes place in _______ direction.

Back 60

Phloem, one

(Note: in this experiment, it shows unidirectional, answer is not wrong)

Front 61

Since the source-sink relationship is ________, (depending on _____________) direction of movement in phloem is bidirectional.

Back 61

Variable, season or plant's needs

Front 62

Movement in phloem is _________ directional.

Back 62

Bi

Front 63

Compare C3 and C4 plants in terms of efficiency of carbon fixation into sugar

Back 63

C4 are twice efficient than C3

Front 64

Compare C3 and C4 plants in terms of water loss during photosynthesis (CO2 fixation)

Back 64

C4 loses only half as much water as C3 for same amount of CO2

Front 65

Environmental factors affecting transpiration

Back 65

Temperature, light, humidity, wind speed

Front 66

Effect of humidity on transpiration

Back 66

More humidity less transpiration

Front 67

Least transpiration occurs at _____________ humidity.

Back 67

100% relative

Front 68

Plant factors affecting transpiration

Back 68

Number and distribution of stomata, percent of stomata open, water status of plant , canopy structure, etc.

Front 69

Transpiration driven ascent of xylem sap depends mainly of following properties of water:

Back 69

Cohesion, Adhesion, Surface Tension, Tensile Strength, Capillarity

Front 70

Cohesion, Adhesion, Surface Tension give water high __________ and high __________.

Back 70

Tensile strength, Capillarity

Front 71

Measurements reveal ghat forces generated by transpiration can create pressures sufficient to lift xylem sized column of water over ___________ high.

Back 71

130 m

Front 72

Who called transpiration necessary evil and unavoidable evil respectively?

Back 72

Curtis, Steward

Front 73

Mesophyll with intercellular spaces and stomata are essentially meant for ___________, but the _____________ is unavoidably responsible for transpiration.

Back 73

Gaseous exchange, leaf anatomy

Front 74

Benefits of transpiration (key words)

Back 74

1. Cooling effect

2. Mineral Nutrition

3. Water movement

4. Optimum turgidity

Front 75

Which benefit of transpiration has exception? The exception is related to _____________.

Back 75

Optimum turgidity, succulent plants

Front 76

Transpiration cools surface by ____________ degrees by ___________.

Back 76

10 to 15, evaporative cooling

Front 77

Transpiration supplies water for __________________.

Back 77

Photosynthesis

Front 78

Transpiration maintains _________________ of plants by keeping cells turgid.

Back 78

Shape and structure

Front 79

Each gram of water adsorbs ______________ heat from leaf and its environment.

Back 79

580 cal

Front 80

Transpiration is important for miner Nutrition because -

Back 80

Minerals are transported through transpiration stream

Front 81

Transpiration provides an efficient means of ____________ and ___________ of salts absorbed by roots.

Back 81

Transport and distribution

Front 82

Water absorbed is translocated through xylem vessels in a ______________.

Back 82

Continuous water column

Front 83

Transpiration maintains ___________ in cells.

Back 83

Optimum degree of turgidity

Front 84

Plants cells function best when there is some water __________ (deficit/excess)

Back 84

Deficit

Front 85

How much amount of water absorbed is lost through transpiration? What is the effect?

Back 85

98%, large amount of energy wasted

Front 86

Transpiration causes water deficit and plants suffer from ___________ due to ______________.

Back 86

Injury, dessication

Front 87

If amount of water lost exceeds the amount of water absorbed, then it causes ____________.

Back 87

Wilting of leaves

Front 88

What cannot be explained by transpiration?

Back 88

Movement of food

Front 89

Succulent plants store water in _______________.

Back 89

Special water storage tissues

Front 90

Stomata movement are brought by changes in ____________.

Back 90

Volume and shape of guard cells

Front 91

Guard cells absorb water from ____________.

Back 91

Subsidiary cells

Front 92

What happens to the shape of guard cells when they absorb water?

Back 92

Pressure on walls causes thin outer wall to bulge out and inner walls to crescent shape

Front 93

Who proposed the proton transport concept? It explains ____________.

Back 93

Levitt, mechanism of opening and closing of stomata

Front 94

According to proton transport concept, the opening and closing of stomata takes place as a result of ______________.

Back 94

Active transport into and out of guard cells

Front 95

Which 2 major compounds are involved in opening and closing of stomata?

Back 95

Starch, CO2

Front 96

During day, starch is converted into __________ in ___________ which in turn dissociates into _________.

Back 96

Malic acid, cytoplasm of guard cells, H+ and malate ions

Front 97

H+ ions given out of cells and ___________ from ________ enter into guard cells.

Back 97

K+ ions, subsidiary cells

Front 98

The intake of K+ ions is balanced by intake of _____. This raises __________ of guard cells.

Back 98

Cl- ions, osmotic pressure

Front 99

Answer w.r.t. mechanism of opening and closing of stomata:

At night photosynthetic activity ceases. What is the effect? (Minor level)

Back 99

CO2 concentration increases

pH becomes acidic 5.0

Front 100

In presence of CO2, an inhibitor hormone _____________ functions and inhibits Uptake of K+ and Cl- ions by -

Back 100

Abscissic acid (ABA)

1.Changing diffusion

2. Changing permeability of guard cells

Front 101

Who proposed Starch sugar hypothesis? It explains ____________.

Back 101

Steward, mechanism of opening and closing of stomata

Front 102

Explain starch sugar hypothesis for opening of stomata

Back 102

Day - chloroplasts in guard cells - photosynthesis - sugar - OP increase - Endosmosis

Front 103

Explain starch sugar hypothesis for closing of stomata

Back 103

Night - sugar to starch - increase TP - exosmosis

Front 104

Mention the parts of stomatal apparatus with numbers

Back 104

1. 2 Guard cells

2. 1 Stoma

3. Many accessory or subsidiary cells

Front 105

Guard cells are ______________. What is the speciality of these cells w.r.t. other cells of the tissue type?

Back 105

Modified Epidermal cells, presence if chloroplasts

Front 106

Shape of guard cells

Back 106

Dicot - kidney shaped

Monocot - Dumbbell shaped

Front 107

How many nuclei do guard cells have? How is the cytoplasm?

Back 107

1, peripheral granular

Front 108

Comment on walls of guard cells

Back 108

1. Inner - Thick, elastic

2. Outer - Thin, elastic, Permeable

Front 109

Inner wall of guard cells is thick due to _____________.

Back 109

Presence of secondary wall layer

Front 110

Opening of stoma is also aided due to _________________ of guard cells

Back 110

Radial orientation of cellulose microfibrils in cell walls

Front 111

What is a stoma?

Back 111

Elliptical pore formed due to specific arrangement of guard cells

Front 112

What are accessory cells?

Back 112

Cells immediately surrounding guard cells

Front 113

____________ are reservoirs of K+ and Cl- ions.

Back 113

Accessory cells

Front 114

Subsidiary cells are reservoirs of ___________.

Back 114

K+ and Cl- ions

Front 115

Which gases are exchanged through stomata?

Back 115

CO2 and O2

(Note: not H2O because it is only diffused out - not involved in exchange)

Front 116

Which gas only diffuses out through stoma?

Back 116

Water vapours

Front 117

How much percent of water absorbed is utilized by plants?

Back 117

2%

Front 118

Define transpiration

Back 118

Evaporative loss of water in form of water vapour by aerial parts of plants

Front 119

Mention types of transpiration with percentage transpiration through each

Back 119

1. Cuticular - 8-10%

2. Lenticular - 0.1%

3. Stomatal - 80-90%

Front 120

What is cuticle?

Back 120

Cuticle is waxy coating on epidermis of leaves

Front 121

Thickness of cuticle varies from plant to plant - True or False

Back 121

True

Front 122

Function of cuticle

Back 122

To Check transpiration

Front 123

Actual cuticular transpiration takes place through _______

Back 123

Cracks in cuticle or by diffusion through thin areas of cuticle

Front 124

Factor affecting Rate of cuticular. Give one application

Back 124

It is inversely proportional to thickness of cuticle.

In xerophytes, cuticle is thicker to decrease water loss

Front 125

Lenticular respiration occurs in -

Back 125

Older bark

Pericarp of woody fruits

Pneumatophores

Front 126

Give the types of leaves based on location of stomata

Back 126

Front 127

Stomata connect -

Back 127

Intercellular spaces between spongy tissues to atmosphere

Front 128

Diffusion can account for only _____________ movement of molecules.

Back 128

Short distance

Front 129

Movement of molecules across a typical plant cells (about _________) takes approximately ________.

Back 129

50 microns, 2.5 sec

Front 130

Water, minerals and food are generally moved by ______________ system.

Back 130

Mass or bulk flow

Front 131

What is mass flow?

Back 131

Mass flow is the movement of substances in bulk or en masse from one point to another as a result of pressure differences between the two points

Front 132

What is characteristic of mass flow?

Back 132

Substances in solution or in suspension are swept along at same pace

Front 133

Bulk flow can be achieved by ___________ or _________.

Back 133

Positive hydrostatic pressure, negative hydrostatic pressure

Front 134

Give one example each of - Positive hydrostatic pressure, negative hydrostatic pressure

Back 134

1. Garden hose

2. Suction through straw

Front 135

Define Translocation

Back 135

The bulk Movement of substances through the conducting or vascular tissues of plants is called Translocation

Front 136

Colour of root hair

Back 136

Colourless

Front 137

Layers of cell wall of root hair

Back 137

Outer pectin, inner cellulose (OPIC)

Front 138

Pathway of water was given by ____________.

Back 138

E. Munch

Front 139

According to E. Munch, what is the path of water?

Back 139

Soil - Epidermis - Cortex - Endodermis - Pericycle - Xylem

Front 140

What are the main pathways of water?

Back 140

1. Apoplast

2. Symplast

3. Transmembrane

Front 141

Apoplastic movement of water takes place through -

Back 141

Cell walls and intercellular spaces

Front 142

____________ pathway does not involve crossing cell membrane.

Back 142

Apoplast

Front 143

Choose correct option in each w.r.t. to apoplast -

1. Osmotic/ Non-osmotic

2. Dependent/ Independent of gradient

3. Due to absorption/ imbibition

Back 143

1. Non-Osmotic

2. Dependent

3. Imbibition

Front 144

Apoplast is continuous movement throughout the transport - True or False giving reason

Back 144

False - Apoplast is continuous movement throughout the plant, except the casparian strips

Front 145

Which pathway of water is faster and why?

Back 145

Apoplast - because it provides no barrier to water movement

Front 146

Xylem and phloem are parts of _____________ pathway. Why?

Back 146

Apoplast - they are non living conduits

Front 147

What is symplastic pathway?

Back 147

Symplastic system is the system of interconnected protoplast through plasmodesmata

Front 148

What is symplast?

Back 148

Neighbouring cells are connected through cytoplasmic strands that extend through plasmodesmata and form cytoplasmic network call symplast.

Front 149

Symplastic movement is aided by ______________.

Back 149

Cytoplasmic streaming

Front 150

Which layer of root cells is impervious to water and why?

Back 150

Endodermis. - band of suberised matrix called casparian strips

Front 151

Movement of water through root layers is ultimately ___________ in __________.

Back 151

Symplastic, endodermis

Front 152

Transmembrane pathway of water is through ____________.

Back 152

All layers of cell (including tonoplast)

Front 153

How are mycorrhiza useful for plants in absorption of water?

Back 153

Very large surface are

Front 154

Give example of obligate association of plant with mycorrhiza

Back 154

Pinus seeds cannot germinate without mycorrhiza

Front 155

Factors affecting water absorption

Back 155

1. Availability of soil water

2. Concentration of soil solution

3. Soil aeration

4. Soil temperature

5. Osmotic pressure of root hair

6. Root anatomy

7. Transpiration

Front 156

How does availability of soil water affect absorption?

Back 156

Decrease in soil water below the permanent wilting percentage causes considerable decrease in absorption of water.

Front 157

How does concentration of soil solution affect absorption?

Back 157

Increased concentration of soil due to presence of salts inhibits

Front 158

What is physiologically dry soil?

Back 158

Soil in which water is concentrated. Having high osmotic pressure. Here water is physically present, but not available for absorption

Front 159

How does soil aeration affect absorption?

Back 159

Low O2 and high CO2 retards growth and disturbs metabolism. Retards rate of absorption

Front 160

Optimum range of soil temperature is ______________ for maximum water absorption.

Back 160

20℃ to 30℃

Front 161

How does osmotic pressure of root hair affect absorption?

Back 161

More OP more rate of absorption

Front 162

How does root anatomy affect absorption?

Back 162

Less root hair, thick walled cortical cells, casparian strips reduce rate of absorption

Front 163

How does transpiration affect absorption?

Back 163

High rate of transpiration more absorption rate

Front 164

What are the two theories explaining why root cells are hypertonic?

Back 164

1. Active Osmotic Theory

2. Passive Transpiration Theory

(AOPT)

Front 165

According to active Osmotic Theory, root hair and cortical cells are hypertonic due to -

Back 165

Metabolic activities in the living cells of root utility ATP

Front 166

In active osmotic theory, after absorption water is transported to next cells due to __________.

Back 166

DPD

Front 167

According to active Osmotic Theory, root cells alternately become _______________.

Back 167

Flaccid and turgid

Front 168

According to passive transpiration theory, what is major factor for absorption of water?

Back 168

Suction or cohesive pull developed by the leaves due to transpiration develops water deficit and draws water from the petiole which pulls water from the stem

Front 169

According to which theory of absorption, metabolic energy is not used?

Back 169

Passive transpiration theory

Front 170

Role of root in absorption according to passive transpiration theory

Back 170

Only ad physical absorbing organ providing surface area for absorption

Front 171

Role of root in absorption according to passive transpiration theory

Back 171

Only ad physical absorbing organ providing surface area for absorption

Front 172

One atmospheric pressure raises a column of water up to _______ m or ______ feet

Back 172

10.3 m, 34 feet

Front 173

Height of

1. Californian Sequoia plant

2. Australian Eucalyptus plant

Back 173

1. 111.6 m or 366.2 feet

2. 114.4 m or 374 feet

Front 174

In a well watered potted tomato plant, cut the stem close to root. What will you observe?

Back 174

Exudation/ bleeding of xylem sap from stump

Front 175

How can we measure the rate of exudation from cut stump? What else can be determined?

Back 175

Fix a rubber tube to cut stem as a sleeve and collect, composition of exudates

Front 176

Root pressure is a (positive/ negative) pressure, responsible for -

Back 176

Positive, pushing up water to small heights in stem

Front 177

Who explained Root pressure?

Back 177

Priestly

Front 178

What was Priestly's explanation of root pressure?

Back 178

Priestly explained that a sort of hydrostatic pressure develops in the root due to accumulation of absorbed water

Front 179

What is guttation?

Back 179

Water loss in its Liquid phase through intact plant parts is known as guttation

Front 180

Guttation is observed in -

Back 180

Grass blades, fern leaflets, leaves of many herbaceous plants

Front 181

Excess water in tips of Grass blades, fern leaflets, leaves of many herbaceous plants etc collects in form of ____________ around special openings called _____________ of __________.

Back 181

Droplets, hydathodes, veins

Front 182

Exuded water from guttation often contains __________. What is the further consequence?

Back 182

Calcium salts, water evaporates off, white crust remains on surface

Front 183

Hydathodes are also known as ___________.

Back 183

Chalk glands

Front 184

2 facts confirming root pressure:

Back 184

1. Living cells are essential in the root for root pressure to develop

2. Oxygen supply effects root pressure

Front 185

What is magnitude of root pressure?

Back 185

Less than 2 atm

Front 186

How is root pressure measured?

Back 186

By manometer sealed over cut stump

Front 187

Root pressure is sufficient only for ____________.

Back 187

Herbs and shrubs

Front 188

Root pressure is not applicable to plants taller than __________

Back 188

20 m or 68 feet

Front 189

Comment on root pressure in tall connifers and other gymnosperms

Back 189

Absent

Front 190

Root pressure is absent in _________.

Back 190

Tallest plants like conifers and other gymnosperms

Front 191

Season dependence of root pressure. So Why root root pressure is not applicable?

Back 191

During summer root pressure is lowest when transpiration rate is very high, wheras during spring it is highest when transpiration rate is low. Actually in summer aerial parts of plants need maximum water

Front 192

What cannot be explained by root pressure theory?

Back 192

Root pressure theory cannot explain ascent of sap through xylem elements which is dead lignified tissue

Front 193

Capillarity theory is a (physical/ living) theory

Back 193

Physical

Front 194

Who gave Capillarity theory?

Back 194

Boehm

Front 195

According to Boehm water rises in narrow tube by -

Back 195

Capillarity develop because of force of surface tension just as oil rises in the wick of an oil lamp

Front 196

According to Capillarity theory, water continues to rise until -

Back 196

Forces of Adhesion and cohesion are balanced by downward force of gravity

Front 197

In a 1 micron Capillary, water rises to a height of ___________, only due to ____________.

Back 197

29 m, resistance to flow of water

Front 198

Demerits of Capillarity theory

Back 198

1. Distance to which water can rise is limited

2. Tube must be open, hollow and open at both ends. In gymnosperms and pteridophytes, xylem is vessel less and tracheids have cross walls at ends

3. Requires free surface, but xylem not in direct contact with water

4. Requires uniform diameter, but not so in xylem

5. Thinner capillary, more rise distance. Opposite in xylem.

Front 199

Who proposed cohesion theory?

Back 199

Dixon and Jolly

Front 200

Magnitude of cohesive force of water ___________

Back 200

350 atms

Front 201

Cell with shrunken protoplasm is called ____________.

Back 201

Plasmolysed cell

Front 202

Water is first lost from ___________ and then from __________.

Back 202

Cytoplasm, vacuole

Front 203

When Plasmolysed cell is placed in hypotonic solution, it reabsorbs by _______________, its protoplast resumes original shape. This is known as ___________.

Back 203

Endosmosis, deplasmolysis

Front 204

What is osmotic pressure?

Back 204

Pressure applied to stop osmosis or the pressure needed to prevent passage of pure water through semi-permeable membrane

Front 205

OP is proportional to -

Back 205

Solute molecules in given amount of solvent

Front 206

Compare OP of hypertonic and hypotonic solution

Back 206

OP of Hypertonic more than OP of hypotonic

Front 207

Give relationship between osmotic pressure and osmotic potential

Back 207

Numerically equal, opposite in sign. Osmotic pressure is positive pressure applied, osmotic potential is negative

Front 208

Give alternate name and symbol for osmotic potential

Back 208

Solute potential - Psi(s)

Front 209

Define turgor pressure

Back 209

The hydrostatic pressure that develops due to endosmosis inside plant cell

Front 210

Define pressure potential

Back 210

The pressure exerted by protoplasts due to entry of water against rigid walls

Front 211

______________ is ultimately responsible for enlargement and extension growth of cells

Back 211

Turgor pressure

Front 212

After endosmosis, why doesn't cell rupture?

Back 212

Rigidity of cell wall

Front 213

What is wall pressure?

Back 213

Protoplasts exert pressure potential on wall. Cell wall is rigid and develops an equal and opposite pressure on cell contents known as WP

Front 214

Relate TP, WP and OP

Back 214

In fully turgid cell, TP=WP=OP

Front 215

Give full form of DPD, along with alternate names and abbreviations

Back 215

Diffusion pressure deficit

Suction force (SF)

Suction pressure (SP)

Front 216

What is DPD?

Back 216

Difference between DP of pure water (1236) and that of solution

Front 217

DPD is proportional to

Back 217

Solute

Front 218

Give formulae of DPD

Back 218

DPD = DP (pure water : 1236) - DP (solution) = OP - TP (WP)

Front 219

DPD in a fully turgid cell is _______

Back 219

Zero

Front 220

When DPD =0, what happens?

Back 220

Endosmosis stops

Front 221

Water potential is denoted by _______ and is measured in _______.

Back 221

Psi(w), pressure units like pascals

Front 222

Pressure potential is denoted by

Back 222

Psi (p)

Front 223

What is value of water potential at atmospheric pressure?

Back 223

Psi(w)=Psi(s)

Front 224

What is water potential?

Back 224

Chemical potential of water or potential energy of water

Front 225

Water potential is proportional to

Back 225

Solvent

Front 226

Give formalae for water potential

Back 226

Psi(w) = Psi (s) + Psi(p) = - OP + TP = - DPD

Front 227

Define solute potential

Back 227

Magnitude of lowering of water potential due to dissolution of solute is called solute potential

Front 228

If pressure greater than atmospheric pressure is applied to solution, it's water potential (increases/decreases)

Back 228

Increases

Front 229

State whether positive or negative:

1. Pressure potential

2. Solute potential

Back 229

1. Usually positive

2. Always negative

Front 230

Comment on movement of water w.r.t. to following:

1. Concentration

2. OP

3. Psi(s)

4. DPD

5. Psi(w)

Back 230

1. Po to per

2. Less to more

3. More to less (less negative to more negative)

4. Less to more

5. More to less (less negative to more negative)

Front 231

Which are the first and second physical processes to occur?

Back 231

Imbibition and Diffusion respectively

Front 232

What is imbibition?

Back 232

Adsorption of water by hydrophilic compounds

Front 233

What happens in Adsorption?

Back 233

Water gets tightly adsorbed on surface of compounds without forming a solution. So, compounds show swelling

Front 234

Meaning of imbibant and imbibant

Back 234

1. Imbibant - substance/solid/colloid which adsorbs water

2. Imbibate - adsorbed liquid

Front 235

What is heat of wetting?

Back 235

Water molecule get highly adsorbed and become immobilized and lose most of kinetic energy in form of heat

Front 236

After imbibition, imbibant increases in ___________.

Back 236

Volume

Front 237

Pre-requisites for imbibition

Back 237

1. Water potential gradient

2. Affinity

Between imbibant and liquid

Front 238

Examples of imbibants

Back 238

Proteins, cellulose, pectic compounds, starch, gum, dry seeds

Front 239

Why is glucose converted into Sucrose for transportation?

Back 239

Sucrose is osmotically active

Front 240

Give following values for pure water and mention whether maximum or minimum

1. DP

2. OP

3. DPD

4. Psi (w)

Back 240

1. 1236 (Max)

2. 0 (Min)

3. 0 (Min)

4. 0 (Max)

Front 241

Give stages of plasmolysis with description

Back 241

1. Limiting - Normal Cell

2. Incipient - Protoplasm withdraws from corners

3. Evident/ Existing/ Obvious - Complete detachment from cell membrane

(LIE)

Front 242

Magnitude of ___________ of water is 350 atms

Back 242

Cohesive force

Front 243

Water has great cohesive force due to ___________.

Back 243

Hydrogen bonds

Front 244

Cohesive and adhesive properties developed form ____________ in xylem.

Back 244

Unbroken continuous water column

Front 245

How is a continuous column of water maintained in xylem?

Back 245

Xylem vessels are short,wide and without end walls. They are placed one above the other and form a tubular structure which extends from the root to the top of the plant.

OR

Adhesive and cohesive forces, continuous anastomizing network of xylem elements

Front 246

Transpiration pull develop a (positive/negative) pressure or ___________ of about ______ atm in xylem sap.

Back 246

Negative, tension, 20

Front 247

H-bond is very (weak/strong).

Back 247

Weak

Front 248

Although, H-bond is very weak, how does is account for strong cohesion?

Back 248

When present in large numbers as in water, a very strong mutual cohesive force is developed

Front 249

According to cohesion theory, what causes pulling force for water?

Back 249

Water lost from mesophyll due to transpiration - increase OP - tension - pulling force

Front 250

What is the supposed demerit of cohesive theory?

Back 250

Due to variations in temperature/ atmospheric pressure, air bubbles may break continuity of water column

Front 251

How do xylem vessels allow collateral flow?

Back 251

Tracheids and vessels are pitted. These pits connect adjacent cells with one another and allow collateral water flow

Front 252

Who showed that under normal conditions, no air bubbles are present in xylem even in last stage of wilting?

Back 252

Renner and Bode

Front 253

What was Renner and Bode's observation?

Back 253

Under normal conditions, no air bubbles are present in xylem even in last stage of wilting