Transport In Plants Flashcards
1
Q
_____ proposed that plants change light energy to chemical energy by transferring an electron in an organised array of pigment molecules and other substances .
A
Melvin Calvin
2
Q
The mapping of the pathway of carbon assimilation in photosynthesis earned _______ Noble prize in 1961 .
A
Melvin Calvin
3
Q
Over SMALL distances , substances move by ______ and by ______ , SUPLEMENTED by ________.
A
Diffusion
Cytoplasmic streaming
Active transport
4
Q
Transport over long distances , proceeds through ___ system .
A
Vascular ( xylem/phloem_
5
Q
Transport over LONG distance is called -
A
Translocation
6
Q
Cytoplasmic streaming is supplemented by -
A
Active transport ( involved in short distance transport )
7
Q
ORGANIC and MINERAL NUTRIENTS undergo _______uni/multi directional transport .
A
Multi
8
Q
______ compounds are synthesised in the photosynthetic leaves are exported to all plants of the plants including STORAGE ORGANS .
A
Organic
9
Q
____ are taken up by the roots and transported upwards into the stem , leaves and growing regions .
A
Mineral nutrients
10
Q
When any part undergoes ______ , nutrients may be withdrawn from such regions and moved to the growing parts .
A
Senescence
11
Q
_______ and other chemical signals are also transported , though in ver. Small amounts .
A
Hormones Or PGRs (plant growth regulators )
12
Q
Plant hormones or PGRs are transported in very small amounts , sometimes in a strictly _______ or_______ manner from where they are synthesised to other parts .
A
Polarised
Unidirectional
13
Q
In a _____ plant ,there is a traffic of compounds ( but very orderly ) moving in diff directions
A
Flowering -angios
14
Q
Movement by DIFFUSION is ______ and may be from ONE CELL TO THE OTHER or from CELL-TO-CELL or from the INTERCELLULAR SPACES OF THE LEAVES TO THE OUTSIDE .
A
Passive
15
Q
Movement by diffusion is over _______ distances .
A
Short
Cell-to-cell
16
Q
In ______ molecules move in. A random fashion .(means of transport )
A
Diffusion
17
Q
What is the NET RESULT of the random motion of the molecules in diffusion .
A
Substances moving from region of HIGER CONC to LOWER conc
18
Q
Energy expenditure takes place in diffusion .T/F
A
F
19
Q
Diffusion is a slow/fast process .
A
Slow
20
Q
Diffusion is not dependent on -
A
A living system
21
Q
Diffusion is very important to ___ . Why ?
A
Plants
It is the ONLY MEANS OF GASEOUS MOVEMENT WITHIN THE PLANT BODY .
22
Q
DIFFUSION in ____ and _____ is obvious but diffusion __solids is more likely rather than diffusion ____ solids .
A
Gases
Liquids
In. , Of
23
Q
Diffusion is the only means of ______ transport _____ the plant body .
A
Gaseous
Within
24
Q
Diffusion rates are affected by -
A
4 things Gradient of conc Permeability of membrane separating them Temp Pressure
25
Diffusion rates are affected by pressure .T/F
T
| Both T and P affect the rate
26
A gradient must already be present for _____ to occur .
Diffusion
| Facilitated diffusion
27
Diffusion rates also depends on _____ of substances .
Size
| Smaller substances diffuse faster
28
The diffusion of any substance across a membrane also depends on its SOLUBILITY in _____ .
Lipids - major constituent of the membrane
29
Substances ______ in lipid , diffuse through the membrane faster .
Soluble
30
Substances that have a ______ moiety find it difficult to pass through the membrane .
Hydrophilic
(Water loving = water soluble = lipid insoluble
Membrane is made of lipid .)
31
The movement of which substances is facilitated ( facilitated diffusion )?
Substances that have a hydrophilic moiety ,(which are lipid insoluble )
32
_____ provide sites at which hydrophilic substances cross the membrane .
Membrane PROTEINS
33
A _____ must already be present for molecules to DIFFUSE even if facilitated by proteins .
Conc gradient
34
In facilitated diffusion , special proteins help move substances across a membrane without ______ .
Expenditure of ATP energy
35
Facilitated diffusion can cause net transport of molecules from LOW to HIGH conc .T/F
F
| Becoz this would require energy
36
Transport rate ( of facilitated diffusion ) reaches a ____ when ALL of the protein transporters are BEING USED ( SATURATION)
Max
37
_____diffusion is very SPECIFIC .
Facilitated
38
Why is facilitated diffusion specific ?
Becoz it allows cells to select substances for uptake . Sensitive to inhibitors
39
Facilitated diffusion is sensitive to ______ which react with ______.
Inhibitors
| Protein side chains
40
The proteins form ______ in the membrane for molecules to pass through. (facilitated diffusion)
Channels
41
Some channels are open , others may be ______ . Some are ____ allowing a variety of molecules to pass through .
Closed
| Large
42
The ______ are proteins that form LARGE PORES in the OUTER membrane of plastids ,mitochondria and some bacteria .
Porins
43
Porins are _____
Proteins
44
Porins are proteins that form large pores in the _____ membrane of plastids , mitochondria and some bacteria .
Outer
45
Porins form pores in the outer membrane of-
Plastids
Mitochondria
Some bacteria 🧫
46
Porins allow molecules upto the size of _______ to pass through .
Small proteins
47
The transport _____ and releases the bound extracellular molecule inside the cell .
Rotates
| Eg - water channel made of 8 types of aqua porins
48
Water channels are made of ______ different types of AQUAPORINS .
8
49
Some carrier or transport proteins allow diffusion only if two types of molecules move together .T/F
T
50
In _______ both molecules cross the membrane in the same direction .
In ______ they move in opposite directions .(types of facilitated difffusion )
Symposium
| Antiport
51
Symports and antiports are ______ active/passive
Passive
52
Symports ,antiports and uniports are types of -
Facilitated diffusion
53
When a molecule moves across a membrane INDEPENDENT f the other molecules , the process is called -
Uniport - a type of facilitated diffusion
54
_____uses energy to transport and pump molecules against a conc gradient .
Active transport
55
Active transport is carried out by _____.
Specific membrane-proteins
56
Different proteins in the membrane play a major role in both ____ and _______ transport .
Active
| Passive
57
______ are proteins that use energy to carry substances across the cell membrane .
Pumps
58
Pumps can transport substances from a __ low conc to a ___conc .
Low to high
| UPHILL TRANSPORT
59
When does the transport rate reach a maximum ? In active transport
When all the protein transporters are being used or are saturated .
60
The carrier protein in active transport is very ____ in what it carries across the membrane .
Specific
| Like enzymes
61
The carrier proteins are sensitive to ______ that react with protein sidechains .
Inhibitors
62
Proteins in the membrane are responsible for _____ and ______ transport .
Facilitated diffusion
| Active
63
Proteins in the membrane show a common characteristic of being -
Highly selective
64
______ in the membrane are liable to saturate , respond to inhibitors and are under hormonal regulation .
Proteins
65
Diffusion whether facilitated or not , take place _____ a conc gradient and ___ energy . ( use / do not use )
Along
| Do not
66
Simple diffusion is highly selective .T/F
F
67
Facilitated transport requires ATP energy or not ?
No . Does not require
68
Out of facilitated , simple diffusion and active tran which one is UPHILL transport ?
Only active ( against the gradient )
69
Which transport mechanism is highly selective ?
Facilitated diffusion
| Active transport
70
Which transport mechanism has TRANSPORT SATURATES ?
Facilitated
| Active transport
71
The _______of cell is nothing but water in which diff molecules are dissolved and suspended .
Protoplasm
72
a watermelon has ____ % of water . Most hebaceous plants have only about _____ % of its fresh weight as dry matter .
92%
| 10-15%
73
In a plant , _____ parts have relatively very little water but ___ parts mostly contain water .
Woody
| Soft
74
A seed appears dry but has water for respiration because it is ALIVE .
T/F
T
75
A mature CORN pant absorbs almost ______ water in a day ,
| While a ____ plant absorbs water equal to its own weight in 5 hours .
3 L
| Mustard
76
Mustard plant absorbs water equal to its own weight in about _____ .( time)
5 hours
77
Water is often the _____ for plant growth and productivity in both agricultural and natural environments .
Limiting factor
78
______ is the concept fundamental to understanding water movements .
Water potential
79
_____ and ______ are the 2 main components to determine WATER potential .
Solute potential
| Pressure potential
80
Water molecules possess _____ . The grater the conc of water in a system , _______ is its K.E .
KE
| Greater
81
The greater the conc of water in a system , greater is its ______ , or _______.
KE
Water potential
(KE = water potential )
82
Pure water has the ______ WATER POTENTIAL .
Highest
Becoz pure water has only water molecules and therefore , an the greater the conc of water molecules = greater their KE = greater water potential
83
Net movement of water molecules in a system occurs from a system with ______ energy to a system with _____ energy .
Higher
| Lower
84
Water will move from a system containing ______ water POTENTIAL to the one having ______ W.P .
Higher
Lower
( higher to lower energy )
85
Process of movement of water from high WP to low WP is called -
Diffusion
| Along conc gradient
86
Water potential is denoted by_____ symbol Psi and is expressed in PRESSURE units such as _______.
Greek
| Pascal
87
If some solute is dissolved in pure water , the solution has fewer ______ molecules , hence the free energy / conc of _____ dec reducing its _______ .
Water
Water
Water potential
88
All solutions have a ______ water potential than PURE water .
Lower
89
The magnitude of the lowering of water potential due to dissolution of a SOLUTE is called -
Solute potential
90
Solute potential is always ______ (+/-)
-ve
| Becoz WP of pure water is 0 . And lowering would be -ve
91
The more the ______ molecules , lower ( more -ve ) is solute potential .
Solute
92
For a solution at ATMOSPHERIC PRESSURE ,_______ potential = ______ potential .
Water
| Solute
93
If pressure greater than Atmospheric press is applied to pure water or a solution , its ________ INCREASES .
Water potential
94
When water enters a plant cell due to diffusion , pressure builts up against _______ making the cell TURGID .
Cel wall
95
When the pressure builts up against the cell wall making the turgid ( due to diffusion of water inside the cell ) , the ____INCREASES .
Pressure potential
96
Pressure potential is usually +/-ve.
+ve
| Exception - plants , -ve potential or tension in water column of xylem helps in transport of water .
97
_______ potential or tension in the water column in the xylem plays a major role in water transport up a stem .
-ve pressure potential
98
Cell membrane / wall is FREELY permeable to water and substances in solution hence is not a barrier t movement .
Cell wall
99
In plants , the cell contains a large vacuole whose contents are -
Vacuolar sap - contribute to the SOLUTE potential
100
The vacuolar sap contributes to the _____ potential in a plant cell .
Solute potential
101
In plant cells , the ____ and ______ together are important determinants of movement of molecules in or out of the CELL .
Cell membrane
| Tonoplast-membrane of vacuole
102
______ is the term used to refer to the diffusion of water across a DIFFERENTIALLY or SELECTIVELY PERMEABLE membrane .
Osmosis
103
Osmosis occurs ____ in response to a DRIVING FORCE .
Spontaneously
104
The NET DIRECTION and RATE of osmosis depends on what factors ??
2
Pressure gradient
Conc gradient
105
Water will move from its region of __ to _____ .
Higher chemical potential (conc)
| Lower chemical potential
106
Place the egg shell in dil . _______ for a few hours . The egg shell dissolves leaving the membrane intact .
HCL
107
The PRESSURE required to PREVENT WATER FROM DIFFUSING is -
Osmotic pressure
108
Osmotic pressure is the function of ______.
SOLUTE CONCENTRATION
109
More the ______ greater will be the PRESSURE required to prevent water from DIFFUSING IN .
Solute conc .
110
Osmotic pressure is the ______ (+/-) pressure applied while osmotic potential is ______ (+/-).
+ve
| -ve
111
The behaviour of the plant cells with regard to water movement depends on the -
Surrounding solution
112
If the external solution balances the ________ of the cytoplasm , it is said to be ISOTONIC .
Osmotic pressure
113
If the external solution is more DILUTE than the cytoplasm , it is called ______
Hypotonic solution
114
If the external solution is more CONCENTRATED than the surrounding solution , it is called -
Hypertonic
115
Cells ______ in hypertonic solution and _____ in hypotonic solution .
Shrink
| Swell
116
________. Occurs when water moves out of the cell and the cell membrane shrinks away from the cell wall .
Plasmolysis
117
Plasmolysis occurs when the cell is placed in a ___ solution TO THE PROTOPLASM .
Hypertonic (has more solutes )
118
During plasmolysis ______ shrinks away from the _______ . (Cell wall/membrane )
Cell membrane
| Cell wall
119
during plasmolysis ,when water moves out ,it is first lost from the _____and then from the _______ .
CYTOPLASM
| VACUOLE
120
During plasmolysis , water is first lost from the vacuole.T/F
F
121
The water when drawn out of the cell through diffusion into the EXTRACELLULAR (outside the cell ) FLIUD causes the _________ to shrink away from the walls .
Protoplast
122
During plasmolysis , the movement of water occurred across the membrane moving from an area of ___( THE CELL) to an area of ____OUTSIDE THE CELL .
High water potential
| Lower water potential
123
If the external solution balances the OSMOTIC PRESSURE of the cytoplasm ,it is said to be -
Isotonic
124
When water flows into the cell and out of the cell and re in EQUILIBRIUM , the cells are said to be -
Flaccid
125
When water flows INTO and OUT of the cell and are in ____ , he cells are said to be FLACCID .
Equilibrium
126
The process of PLASMOLYSIS is usually _______ (reversible/irreversible)
Reversible
127
When a cell is placed in a______ solution , water diffuses into the cell causing the CYTOPLASM to build up a pressure AGAINST THE WALL .
Hypotonic (higher water potential or DIL .solution as compared to the cytoplasm )
128
When the cell is placed in hypotonic solution , the cytoplasm builds up a pressure against the CELL WALL , that is called -
Turgor pressure
129
The pressure exerted by the protoplasts due to the entry of water against the rigid WALLS ( cell wall) is called -
Pressure potential
130
Becoz of the RIGIDITY of ______ , the cell does not rupture due to turgor pressure .
Cell wall
131
The ________ is ultimately responsible for ENLARGEMENT and EXTENSION growth of cells .
Turgor pressure
132
The pressure exerted by ___ due to ____ against the ____ is called PRESSURE POTENTIAL (Wp).
Protoplast
Entry of water
Rigid walls
133
Turgor pressure is developed when the cell is placed in a hypertonic/hypotonic .
Hypotonic
134
When the cell is placed in a hypotonic solution , ___ builds up a pressure against the _____ .
Cytoplasm
Cell wall
(Turgor pressure )
135
What is the TURGOR PRESSURE responsible for ?
Enlargement and extension growth of cells
136
_______ is a special type of DIFFUSION when water is absorbed by SOLIDS-COLLOIDS causing them to INCREASE IN VOLUME .
Imbibition
137
Imbibition is a special type of -
Diffusion
138
Imbibition is a type of diffusion in which water is absorbed by -
Solids-colloids
139
The classical example of imbibition is absorption of water by _____ and _____ .
Seeds and dry wood
140
If it were not for the pressure due to _____ , seedlings would not have been able to emerge out of the soil .
Imbibition
141
In Imbibition , water movement is ______ conc gradient .
Along
142
Why do seedlings undergo imbibition ?
Becoz imbibition is along a conc gradient . And seedlings has almost no water hence absorb water easily .
143
Water potential gradient between ___ and _____ is essential for IMBIBITION .
Absorbent
| Liquid imbibed
144
To imbibe any liquid , affinity between the ______ and ______ is also a pre-requisite .
Adsorbant
| Liquid
145
Movement of a molecule across a typical plant cell (about _____um ) takes approx. ______ (time) . By diffusion
5
| 2.5
146
Sometimes the sites of production or absorption and sites of storage are too far from each other , therefore ______and ______ would not suffice .
Diffusion
| Active absorption
147
Active absorption is involved in LONG DISTANCE TRANSPORT .T/F
F
148
Water and minerals and food are generally moved by a ____or______ system .
Bulk
| Bulk system
149
Mass flow is the movement of substances in bulk or ______ from one point from other as a result of pressure difference .
en masse
150
Mass flow is the movement of substances as a result of -
Pressure difference between 2 points
151
It is a characteristic of ______ that substances whether in solution or in suspension are swept along at the same pace .
Mass flow
152
Give a characteristic of mass flow -
Substances whether n solution or in suspension are swept along at the same pace as that In flowing river.
153
Mass flow or bulk flow is unlike _______ in which substances move independently depending on their conc gradient .
Diffusion
154
Bulk flow can be achieved either through _______ or a _______ .
Positive hydrostatic pressure gradient
| Negative hydrostatic pressure gradient
155
In a a garden hose , _____ pressure gradient can be seen .
Positive
156
During suction through a straw , _______ pressure gradient can be seen .
Negative
157
The bulk movement of substances through the conducting or vascular tissues of plants , is called -
Translocation
158
Xylem is associated with translocation of mainly _____,_____,_____and _____.
Water
Minerals
Some organic nitrogen
Hormones
159
Phloem, translocates a variety of ____ and __________ .
Organic
| Inorganic solutes
160
Root hairs are thin-walled slender extensions oƒ_______ that greatly _______the surface area for absorption .
Root epidermal cells
| Increase
161
Water is absorbed along with _____ , by root hairs , purely by ______ .
Mineral solutes
| Diffusion
162
Once water is absorb by the root hairs , it can move deeper into the root layers , by -
2distinct pathways
Apoplast
Symplast
163
________ is a system of adjacent cell walls that is continuous throughout the plant , except at the casparian strips in the roots .
Apoplast
164
Apoplast is continuous /discontinuous .
Continuous , except at the casparian strips
165
The apoplastic movement of water occurs exclusively through the ________ and ______ .
Intercellular spaces
| Walls of the cells
166
Movement through the _______ does not involve crossing the cell membrane .
Apoplast
167
Apoplastic movement is dependent on -
gradient
168
The ______does not provide any barrier to water movement .
Apoplast
169
In______ , water movement is through MASS FLOW .
apoplast
| Becoz it does not provide any barrier to water movement
170
Movement through apoplast does not involve CROSSING the -
Cell membrane
171
The _____ movement of water occurs through intercellular spaces and walls of cell .
Apoplastic
172
Apoplastic movement is dependent /independent on the gradient.
Dependent
173
As Water evaporates in the intercellular spaces or the atmosphere , tension develops in the ______of water in the _______ .
Continuous stream
| Apoplast
174
Mass flow of water occurs through ______ and _______ properties of water .
Adhesive
| Cohesive
175
Why does MASS FLOW of water occurs through adhesive and cohesive properties of water ?
Becoz due to evaporation of water , tension develops in the continuous stream of APOPLAST .
176
The _______ is the system of interconnected protoplasts
Symplastic system
177
Neighbouring strands are connected through _____ that extend through the ________ in SYMPLASTIC movement .
Cytoplasmic strands
| Plasmodesmata
178
______ movement in symplast is through PLASMODESMATA .
Intercellular
179
During _____ movement , the water travels through the cells - their cytoplasm .
Symplastic
180
In symplastic pathway , water has to enter the cEll through the ______ , hence the movement is relatively ____slower /faster .
Cell membrane
| Slower
181
Movement in symplastic ______ a potential gradient .
Down
| Like apoplast .
182
Symplastic and apoplastic movement are dependent on potential gradient . T/F
T
183
Symplastic movement may be aided by -
Cytoplasmic streaming
184
Cytoplasmic streaming can be observed in the cells of -
Hydrilla leaf
185
In hydrilla leaf , movement of _______ due to streaming (cytoplasmic) is easily visible .
Chloroplast
186
Plasmodesmata are involves in symplastic /apoplastic pathway .
Sym
187
Pathway that is continuous throughout the plant -
Apoplastic
188
Most of the water flow in the roots occurs via -
Apoplast
189
Why does most of the water flow int he roots occurs via the apoplast ?
Since the CORTICAL CELLS are loosely packed and hence offer no resistance to water movement .
190
In roots , the _______ cells are _____ packed and hence offer / do not offer resistance to water movement . APOPLASTIC pathway
Cortical
Loosely
Do not offer
191
The _______ boundary of ______ , the endodermis is impervious to water .
Inner
| Cortex
192
The inner boundary of cortex , the endodermis is impervious to water due to a band of -
Suberised matrix-casparian strip
193
Water molecules are unable to penetrate the casparian strip , therefore they are directed to ____ regions (not suberised ) into the cell proper through the _____ .
Wall
| Membranes
194
Water molecules moving in _____ pathway are directed INTO THE CELL PROPER due to casparian strip .
Apoplastic
195
Casparian strips offers resistance to -
Apoplastic ( through cell walls )
| When unlike normal conditions , thy have to cross the CELL MEMBRANE
196
Due to casparian strips , water moves through the _______ and again crosses a membrane to reach the ____ .
Symplast
| Xylem
197
The movement of water layers is ultimately _______ in the ______ .
Symplastic
| Endodermis
198
The only way water and other solutes can enter the vascular cylinder is -
Symplastic movement (in endodermis)
199
To reach the cells of xylem , water molecules have to cross -
Cell membrane
| After moving through symplast
200
Once inside the ______ ,water is again free to move between the cells as well as through them .
Xylem
201
In young roots water enters directly into ______ or/and______ .
Xylem vessels
| Tracheids
202
Xylem ______ and _____ are parts of apoplast .
Vessels
Tracheids
(Non-living)
203
Xylem vessels and tracheids are parts of _______ becoz these are _________ .
Apoplast
| Non-living conduits
204
Some plants have additional structures associated with them that help in _______ , for example -MYCORRHIZA
Water (and mineral )absorption
205
A mycorrhiza is a symbiotic association of a fungus with a _____ .
Root system
206
In mycorrhiza , the ______ filaments form a network around the young _____ or they penetrate the _____ .
Fungal filaments
Root
Root cells
207
In mycorrhiza _______ have a very large SURACE AREA that absorb mineral ions and water from the soil from a much larger volume of soil that perhaps a ROOT CANNOT DO .
Hyphae ( fungal)
208
The ______ provides minerals and water to the _____ , which in turn provide sugar and N -containing compounds to the ______ . In a mycorrhizal association .
Fungus
Roots
Mycorrhiza
209
Some plants have an _____ association with the mycorrhiza .eg pinus seeds .
Obligate
210
_______ cannot germinate and ESTABLISH without the presence of mycorrizha .
Pinus seeds
211
In a mycorrhizal association , the fungal component provide ____ to the roots and roots provide _______ to the fungus .
Fungus provides -minerals
And water
Roots provide -sugars and N-containing compounds
212
As various ions from the soil are ______ transported into the vascular tissues of the roots , water follows (its _____) and _____ the pressure inside the xylem .
Actively
Potential gradient
Increases
213
The ______ pressure that builds up inside xylem of roots is called ROOT PRESSURE
Positive
214
_______ is responsible for pushing up water to small heights in the stem
Root pressure .
215
Root pressure is +ve/-ve .
+ve
216
Positive root pressure is due to -
Active transportation of ions into the xylem of roots
217
Drops of water oozing out of a cut stem in early morning (when there is plenty of atmospheric pressure )is due to -
POSITIVE ROOT PRESSURE
218
If we fix a rubber tube to the cut stem , due to root pressure , we can actually collect and measure the rate of ______and also determine the composition of -
Exdudation
| Exudates
219
Effect of root pressure is also observable at night and early morning when evaporation is _____ .
Low
220
Water loss in its LIQUID PHASE from the tip of grass blades and leaves of many herbaceous parts is known as -
Guttation
221
Guttation occurs due to -
Positive root pressure
222
Guttation and exudation occurs becoz of -
+ve root pressure
223
Guttation can be seen when and where ?
At night and early morning when EVAPORATION IS LOW and excess water collects in the form of DROPLETS around special openings of VEINS near the TIP OF GRASS BLADES and LEAVES of many HERBACEOUS PARTS .
224
______ can , at best , only provide a modest push in the overall process of water transport .
Root pressure
225
Root pressure does not play a major role in water transport up a tall tree .T/F
T
226
What is the greatest contribution of ROOT PRESSURE ?
To RE-ESTABLISH the continuous chains of water molecules in the xylem which often break under the enormous TENSION CREATED BY TRANSPIRATION .
227
Continuous chains of water molecules in the xylem , often break under the enormous ____ created by _______ .
Tension
Transpiration
( Fixed by root pressure )
228
Root pressure accounts for majority of water transport .T/F
F
229
If root pressure does not account for majority of water transport , then how to most plants meet their need?
By transpiration pull
230
Upward flow of water through xylem can achieve fairly high rates , upto ______ metres PER HOUR .
15
231
The driving force for the pull of water upwards is -
Transpiration
232
Process of transpiration is referred to as the ___________ MODEL of water transport .
Cohesion-tension-transpiration pull model
233
______ is TRANSIENT in plants .
Water
234
_______ % of water reaching the leaves is used in PHOTOSYNTHESIS and PLANT GROWTH .
Less than 1 %
235
The water lost through ______ in the LEAVES is called TRANSPIRATION
Stomata
236
Less than 1% of the water reaching the leaves is used in -
Photosynthesis
| Plant growth
237
Transpiration is the ________ loss of water by plants .
Evaporative
| Guttation -liquid loss
238
Transpiration mainly occurs through -
Stomata
239
Functions of stomata -
Loss of water vapour in TRANSPIRATION
| exchange of O2 and CO2
240
Stomata are open during the _____ time and close during the _____ .
Day
| Night
241
The immediate cause of opening or closing of stomata is the ______________.
Change in turgidity of GUARD CELL .
242
Change in TURGIDITY OF _______ is the immediate cause of opening and closing of stomata .
Guard cell
243
The inner wall of each guard cell lies towards the _______ and is ____ and ____ .
Pore or stomatal aperture
Thick
Elastic
244
The ____ wall of each guard cell is elastic .
Inner
245
When turgidity increases within the 2 guard cells flanking each stomatal aperture or pore , outer walls _______ out , an force the inner walls into a ___ shape .
Bulge out
| Crescent shape .
246
_____ walls bulge out and force the _____ walls into a crescent shape due to turgidly .
Outer
| Inner
247
In a guard cell ,___wall is thin and _____ thick.
Outer
| Inner
248
The opening of stomata is also aided due to the orientation of _______ in the ______ of GUARD CELLS .
Microfibrils
| Cell walls
249
________ are oriented ______ rather than _______ making it easy foe the stoma to open .
Cellulose microfibrils
Radially
Longitudinally
250
Cellulose microfibrils are oriented longitudinally .T/F
F
251
When the guard cells ______ due to water loss (or water stress) , the ______ walls regain their original shape .
Lose turgor
| Elastic inner
252
When the guard cells lose turgor , due to water loss ( water stress ) , the _____ becomes flaccid and the ______ closes .
Guard cells
| Stoma
253
Usually the ______ surface of a dorsiventral leaf has a greater number of stomata .
Lower . Abaxial
254
Transpiration is affected by several EXTERNAL FACTORS like -
```
4
Temp
Light
Humidity
Wind speed
```
255
PLANT FACTORS which affect transpiration include -
```
4
Number and distribution of stomata
Per cent of open stomata
Water status of plant
Canopy structure
```
256
The transpiration driven ASCENT of xylem sap depends mainly on the _____ properties of _____ .
Physical
| Water
257
The physical properties of water o which the ascent of depends are -
Cohesion
Adhesion
Surface tension
258
MUTUAL attraction between water molecules is called -
Cohesion
259
Adhesion is the attraction of water molecules to ______ surfaces . For example -
Polar surfaces
| Surface of TRACHEARY ELEMENTS
260
Water molecules are attracted to each other in the _____ phase more than to water in the _____ phase .
Liquid
| Gas
261
Water molecules are attracted to each other in the liquid phase more than to water in the gas phase . This property of water is called -
Surface tension
262
Attraction of water to polar surfaces is called -
Adhesion
263
The 3 properties of water ( cohesion,adhesion and ST )give water HIGH _______ and _____ .
Tensile strength - ability to resist a pulling force
| High Capillarity -ability to rise in the tube .
264
In plants , CAPILLARITY is aided by the _______of the TRACHEARY ELEMENTS (tracheids and vessel elements ) .
Small diameter of TRACHEARY elements
265
Because of ______ conc of water vapour in the ATMOSPHERE as compared to SUBSTOMATAL CAVITY and intercellular spaces ,water diffuses into the surrounding air .
Lower
266
A pull is created when lower conc of water vapour in the atmosphere as compared to the _____ and _______ , water diffuses into the ______ .
SUBSTOMATAL cavity
Intercellular spaces
Surrounding air
267
As after evaporates through the stomata , since the thin film of water over the cells is continuous , it results in the pulling of water ______ by ______ into the leaf from the xylem .
Molecule by molecule
268
Measurements reveal that forces created by TRANSPIRATION can create PRESSURES sufficient to LIFT _______ column of water over ______ METERS HIGH .
A xylem sized
| 130 m
269
The capability of water to rise in THIN TUBES ( due to the properties of water ) is called -
Capillarity
270
The TRACHEARY elements which have small diameter for capillarity are -
Tracheids
| Vessel elements
271
______ transports minerals from soil to al parts of the plant .
Transpiration
272
______ cools leaf surface , sometimes _______ to _____ degrees by EVAPORATIVE COOLING .
Transpiration
| 10-15 degrees
273
Transpiration cools leaf surface by -
Evaporative cooling
274
Transpiration maintains the _____ and _____ of the plants by keeping cells _____ .
Shape
Structure
Turgid
275
An actively photosynthetic plant has an _____ need for water .
Insatiable
276
The _____ of rain forests is due to the vast cycling of water from root to leaf to atm and back to the soil .
Humidity
277
The evolution of C4 PHOTOSYNTHETIC system is probably one of the strategies for maximising the _______ while MINIMISING ______ .
Avaibility of CO2
| Water loss
278
C 4 plant are twice as efficient as C3 plants in terms of ______ .
Fixing CO2 (making sugars )
279
____ plant loses only half the amount of water as a __ plant for the same amount of CO2 fixed .
C4
| C3
280
Unlike water , all MINERALS cannot be ____ absorbed by roots .
Passively
281
Which 2 factors account for the fact that minerals cannot be passively absorbed by the roots?
1 - minerals are present as CHARGED PARTICLES (IONS )in the SOIL , which CANNOT MOVE ACROSS CELL MEMBRANE .
2-CONC OF MINERALS IN THE SOIL is usually LOWER than the conc of minerals in the ROOT .
282
Most minerals must enter the roots by into the CYTOPLASM of _____ cells .
Active absorption
| Epidermal
283
The ACTIVE uptake (requires ATP) of ion is partly responsible for the _____ in the roots and therefore for the uptake of water by ____ .
Water potential gradient
Osmosis
(Active absorption of ions (minerals)——>water potential gradient created ————>osmosis )
284
Some ions move into the epidermal cells of the root passively .T/F
T
285
Minerals are present in the soil as ___ which cannot move across ____ .
Ions
| Cell membrane
286
The conc of minerals in the ____ is usually LOWER than their conc in the ____ .
Soil
| Root
287
Ions are absorbed from the soil by both ____ and ____ transport .
Active
| Passive
288
______ in the membrane of root air cells actively pump ions from soil into the cytoplasm of the epidermal cells .
Specific proteins
289
Like all cells , the _____cells have many TRANSPORT PROTEINS embedded in their ______ .
Endodermal
| Plasma membrane
290
___ cells let some solutes cross the membrane nut not others (becoz of special proteins ).
Endodermal
291
Transport proteins of endodermal cells are ______ .
Control points
292
What are control points in the endodermal cells .
Transport proteins where a plant adjusts the QUANTITY and TYPES of solutes that reach the xylem .
293
Root endodermis becoz of the layer of Suberin has the ability to TRANSPORT IONS in ______ direction .
1 direction ONLY
294
Transport proteins of endodermal cells are CONTROL POINTS where a plant adjusts the ______ and ______ of SOLUTES reaching the xylem .
Quantity
| Types
295
After the ions have reached the xylem through active or passive transport , their further movement up the stem is through -
Transpiration stream
296
The chief SINKS of the MINERAL elements are ______regions of plants such as the -
```
Growing regions
Apical and lateral meristems
Young leaves ,
Developing flowers 💐,fruits and seeds
STORAGE ORGANS
```
297
Unloading of mineral ions occurs at the _____ through __ and ____ uptake by these cells .
Fine vein endings
Diffusion
Active
298
Mineral ions are frequently _______ ,particularly from OLDER ,SENESCING PARTS .
Remobilised
299
Before leaf fall in __ plants , minerals are removed to other parts .
Deciduous
300
Elements most readily mobilised are -
Phosphorous , sulphur , nitrogen , potassium
301
Some elements that are STRUCTURAL COMPONENTS like_______ are not remobilised .
Ca
302
An analysis of the xylem exudates shows that though some of the ______ travels as INORGANIC ions , much of it is carried in the ORGANIC form as AMINO ACIDS .
N
303
Much of nitrogen is carried is carried in the _____ from as ___ .
Organic
| Amino acids
304
Like N , small amounts of ___ and ____ are carried as ORGANIC compounds .
P
| S
305
Xylem transportes only only inorganic nutrients and phloem only organic materials .T/F
F
| Not necessarily
306
Food , primarily _____ is transported by the vascular tissue phloem from SOURCE to SINK .
Sucrose
307
Which part of the plant is referred to as the SOURCE -
| And sink ?
LEAF
| Part which needs or stores food 🥘
308
The ______ and ______ may be reversed depending on the SEASON or the plant’ NEEDS .
Source
| Sink
309
Sugar stored in the ______ may be mobilised t becomes he SOURCE of food in early SPRING when the ____ of trees act as SINK .
Roots
| Buds
310
Why do buds of trees act as sink during early spring ?
Becoz they need energy for growth and development of photosynthetic apparatus
311
Why is the direction of flow in phloem is BIDIRECTIONAL ?
Becoz source-sink relationship is variable
312
Phloem sap is mainly ____ and _____ .
Water
| Sucrose
313
Phloem sap is mainly water and sucrose but other _____ , ____ and ______ are also transported or trans located through phloem .
Sugars
Hormones
Amino acids
314
The direction of movement in phloem is -
Bi-directional
315
The =accepted mechanism used for the translocation of SUGARS from source to sink is called -
Pressure flow hypothesis
316
______ is prepared at the source by photosynthesis , so it is converted to ____.
Glucose
| Sucrose
317
After conversion of glucose into sucrose , the sugar is moved in the form of sucrose into. The ____ cells and then into theLIVING _______ cells by active transport .
Companion
| Living PHLOEM SEIVE TUBE cells
318
Sucrose is a _____.
Disachchide
319
Sucrose from companion cells is moved to sieve tube cells by -
Active transport
320
The processs of loading of SUCROSE at the source produces a ________ condition in the PHLOEM .
Hypertonic
321
What happens when loading of sucrose produces a hypertonic condition in the phloem ?
Water in adjacent XYLEM moves into the PHLOEM by osmosis .
322
As osmotic pressure builds up in the phloem (due to movement of water from xylem into phloem by. Osmosis), ______ will move to areas of _______ PRESSURE .
Phloem sap
| Lower
323
At the __source/sink , OSMOTIC PRESSURE MUST BE REDUCED .
Sink -reduced
| Source-increased
324
Again ______ is necessary to move the SUCROSE out of the PHLOEM SAP and into the cells which will use the sugar .
Active transport
325
The cell use sugar from sucrose by converting it into -
Energy
Starch
Cellulose
326
As sugars are removed from from the PHLOEM SAP , the _________ DECREASES in the PHLOEM and ______ moves out of phloem
Osmotic pressure
| Water
327
The movement of sugars in the phloem begins at the ______ , where sugars are loaded or ________ into the sieve tube .
Source
| Actively transported
328
Loading of phloem sets up a _____ that facilitates the ______movement in the phloem .
Water potential gradient
| Mass
329
Sieve tube cells form long columns with _____ in their ______ called _______ .
Holes
End walls
Sieve plates
330
________ pass through the holes in the sieve plates , so forming CONTINUOUS FILAMENTS .
Cytoplasmic strands
331
As ______ in the sieve tube of PHLOEM INCREASES , ______begins and the sap moves through the phloem .
Hydrostatic pressure
| Pressure flow
332
At the sink , INCOMING SUGARS are ______ transported out of the phloem and removed as ______ .
Actively
| Complex carbohydrates
333
The LOSS OF SOLUTE produces a HIGH ______ in the phloem and water moves ______ .
Water potential
| Out-into the xylem finally
334
An experiment called ______ was used to identify the tissues through which food is transported .
Girdling
335
Girdling shows that phloem is responsible for translocation of food and that transport takes place in _____ direction i.e towards the roots .
One
336
Sugars solution flows to regions of LOW -
Turgor pressure
337
What happens when sugars leave sieve tubes ?
Water follows by osmosis
338
Numerically , osmotic pressure is equivalent to ________ , but the sigh is NEGATIVE .
Osmotic potential
339
Sugars enter sieve tubes and water follows by osmosis . Which is = to _______ .TURGOR PRESSURE .
HIGH
340
The water when drawn out of the cell through diffusion into the extracellular FLIUD causes the ______ to shrink away from the walls .
Protoplast
