1. Plants Cell
cell wall
cytoplasm
vacuole
cell membrane

2. freely permeable so it lets most of molecules to go through
osmosis does not occur
cell membrane
beneath cell wall
selectively permeable
cell wall

3.  Water Relations of Plant - Turgor plant cell put in distilled water
net water movement into the cell by osmosis 
plant cell contains solutes
water potential lower than pure water
vacuole and cytoplasm swells

4. cytoplasm is pushed against cell wall
turgor
turgor is present because:
cell wall is rigid and strong, cell bursting is prevented
hydrostatic pressure develops inside the cell

5. When water potential of cell = water potential of water
tendency of the cell to give out water increases
water potential increases
When water potential of cell = water potential of water
Turgor occur (cell cannot take in any water) the cell is turgid

6. Water Relations of Plant - Plasmolysis
plant cell in concentrated solution
The whole phenomenon is called plasmolysis and cell is plasmolysed
net water movement out of the cell by osmosis
flaccid
vacuole and cytoplasm shrink
cytoplasm is torn away from cell wall

7. Turgidity of Plant Cells
cell membrane separated
from cell wall
cell wall
cytoplasm
vacuole
enlarged
vacuole
very small
solution here is the same
as the external solution
plasmolysed cell
(in hypertonic sol)
turgid cell
(in hypotonic sol.)

8. Cells in Different Solutions
Solution Concentration
hypotonic
hypertonic
animal cells
(e.g. RBC)
haemolysis
shrink
plasmolysis
(cell is flaccid)
plant cells
turgid

9. Investigation 11.2
To Investigate the Effects of Sucrose Solution and Tap Water on Epidermal Cells of Red Onion Scale Leaf or Rhoeo Discolor Leaf

10. fleshy scale leaf of red onion bulb
forceps
filter paper
epidermis
What do you observe when the epidermal strip is placed in the concentrated sucrose solution ?
Ans: The coloured cytoplasm shrinks.

11. fleshy scale leaf of red onion bulb
forceps
filter paper
epidermis
Explain your observation.
Ans: When the piece of epidermis is placed in concentrated solution, cells lose water by osmosis as the cells have a higher water potential than the sugar solution.

12. fleshy scale leaf of red onion bulb
forceps
filter paper
epidermis
What has happened to the cells in tap water ?
Ans: The coloured cytoplasm swells and cells become turgid.

13. fleshy scale leaf of red onion bulb
forceps
filter paper
epidermis
Explain your answer.
Ans: When the piece of epidermis is placed in tap water, cells gain water by osmosis as the surrounding tap water has a higher water potential than the cells.

15. Investigation 11.3
Effects of Concentrated Sucrose Solution and Tap Water on Raw Potato Strips

16. What has happened to the potato strips ?
petri dish
water
20% surcose solution
raw potato strips A B
What has happened to the potato strips ?
Ans: Potato strip A increases in both weight and length while potato strip B decreases in both weight and length.

17. petri dish
water
20% surcose solution
raw potato strips A B
Explain your answer.
Ans: For potato strip A, it gains water by osmosis so both of its weight and length increase but for potato strip B, it loses water by osmosis so its weight and length decrease.

18. Transpiration
an evaporation of water in form of water vapour from the surface of plant to atmosphere
it mainly takes place in leaves where there are some openings called stomata

19. more water loses from the lower surface of the leaf than the upper one as more stomata present on the lower surface
it also happens in lenticels and cuticle

20. Transpiration in Leaves
a thin film of moisture is covered with each mesophyll cell
the moisture evaporates from mesophyll cells into intercellular spaces and diffuses out of stomata into atmosphere

21. water potential of cells losing water decreases so they draw water from deeper cells in the leaf by osmosis. This in turn, draws water in xylem vessels into leaf to replace the loss

22. Experiment to Show that Water is Given Off During Transpiration
Investigation 11.4
Experiment to Show that Water is Given Off During Transpiration

23. What do you observe in the polythene bags ?
Ans: The one enclosing plant A becomes misty while nothing can be noticed in the one enclosing plant B.

24. How can you show that it is water ?
polythene bag A B
How can you show that it is water ?
Ans: We can use anhydrous cobalt chloride paper to test it. It will turn the paper from blue to pink or we can use anhydrous copper sulphate. Water will turn it from white to blue.

25. What conclusions can you draw from the results ?
polythene bag A B
What conclusions can you draw from the results ?
Ans: We can conclude that a leafy shoot gives off water during transpiration.

26. To Measure the Rate of Transpiration by Using a Simple Potometer
Investigation 11.5
To Measure the Rate of Transpiration by Using a Simple Potometer

27. graduated capillary tube
air/water meniscus
graduated capillary tube
reservoir
leafy shoot
tap
What are the environmental conditions under which transpiration occurs quickly ?
Ans: It is under dry, warm and windy conditions.

28. graduated capillary tube
air/water meniscus
graduated capillary tube
reservoir
leafy shoot
tap
Does this apparatus give you an accurate measurement of the rate of transpiration ?
Ans: No. It is because it only measures the rate of water uptake by the leafy shoot …
Ans: In addition, it is too small to fit the whole root system and this may affect the rate of water uptake.

29. graduated capillary tube
air/water meniscus
graduated capillary tube
reservoir
leafy shoot
tap
Sometimes you may introduce an air bubble into the capillary tube. State the advantage of this method.
Ans: Movement of the air bubble is easier to observe than that of air/water meniscus.

30. graduated capillary tube
air/water meniscus
graduated capillary tube
reservoir
leafy shoot
tap
Sometimes you may introduce an air bubble into the capillary tube. State the disadvantage of this method.
Ans: Friction between the capillary wall and the bubble may affect the movement of bubble.

31. Environmental Factors Affecting the Rate of Transpiration
There are five environmental factors which affect the rate of transpiration. They are:
(I) Light Intensity
(II) Temperature
(III) Humidity
(IV) Wind Speed
(V) Water Supply

32. Light Intensity
stomata open in light, so plants can get enough carbon dioxide from atmosphere for carrying out photosynthesis
light will increase temperature so increases the rate of transpiration

33. Temperature rate of evaporation of water from mesophyll cells
relative humidity of air outside leaf
rate of diffusion of water vapour from intercellular space in leaf to outside

34.  Humidity humidity outside rate of transpiration
it makes the diffusion gradient of water vapour from moist intercellular space of a leaf to the external atmosphere steeper 

35. Wind Speed & Water Supply
wind blows
lack of water
water vapour around the leaf sweeps away
soil dries, plant wilts and stomata close
transpiration rate
transpiration rate
INCREASES
DECREASES

36. Stomata
stomata are pores in the epidermis which gaseous exchange takes place during photosynthesis (or respiration)
find mainly in lower epidermis of dicotyledonous leaves and stems

37. Guard Cells
each stomata is surrounded by two guard cells which possess chloroplasts
its inner wall is thicker than outer wall
it is kidney-shaped
stoma
guard cell

38. Distribution of Stomata in Leaves
normal plants
mainly on the lower surface of leaves
floating plants
mainly on the upper surface
leaves may also have air sacs to keep them afloat so they can carry out gaseous exchange

39. submerged aquatic plants
no stomata (not required since gaseous exchange can be carried out by diffusion though the leave surface)
no cuticle (the primary function of cuticle is to prevent excess water transpiration which is not present in aquatic plants)

40. Investigation 11.6
Experiment to Investigate Stomatal Distribution in a Leaf by Using Cobalt Chloride Paper

41. Obtain a potted plant. Using sellotape stick a small square
cobalt chloride paper
sellotape
Obtain a potted plant. Using sellotape stick a small square
of anhydrous cobalt chloride paper onto each surface of
a leaf of the plant. Record the time taken for the cobalt
chloride paper on each surface of the leaf to turn pink.

42. Which piece of cobalt chloride paper turns pink first?
sellotape
Which piece of cobalt chloride paper turns pink first?
Ans: The piece of cobalt chloride paper attached to the lower epidermis of the leaf turns pink first.

43. Ans: It is because more stomata are present in the lower epidermis.
cobalt chloride paper
sellotape
Explain your answer.
Ans: It is because more stomata are present in the lower epidermis.

44. Why is it important to handle cobalt chloride paper with forceps?
sellotape
Why is it important to handle cobalt chloride paper with forceps?
Ans: It is because there is moisture on human fingers so the paper may turn pink before sticking onto the surfaces of leaves.

45. To Observe the Release of Air Bubbles from Leaves placed in Hot Water
Investigation 11.7
To Observe the Release of Air Bubbles from Leaves placed in Hot Water

46. Which surface has more air bubbles coming off?
forceps
hot water
leaf
Which surface has more air bubbles coming off?
Ans: There are more air bubbles appear on the lower surface of the leaf.

47. Where does the air come from?
forceps
hot water
leaf
Where does the air come from?
Ans: It is in the air spaces between the mesophyll cells in leaf which expands on heating and passes out through stomata of the leaf.

48. What does the result show?
forceps
hot water
leaf
What does the result show?
Ans: The result shows that more stomata are present on the lower epidermis of the leaf.

51. Structure of Root Root Cap a protective layer at the very tip of root
to protect the delicate cells of root from being damaged as the root grows down through the soil
Epidermis
cover the rest of root
absence of cuticle so water can enter

52. Growing Point
behind root cap
cells are capable of active division
Region of Elongation
more elongated than cells in growing point and have large vacuoles

54. Region of Root Hair
little way behind root tip
root hair are thin-walled extension of epidermal cells of root
increase surface area for uptake of water and mineral salts

55. Vascular Tissue
further from the tip of root
contain xylem and phloem
xylem transport absorbed water to every part of plant

59. Absorption of Soil Water by Root Hairs
soil water is a dilute solution of salts which is more dilute than cell sap and cytoplasm in root hair
water will pass by osmosis into root hair through cell wall and cell membrane

61. reduction of effective pressure at the top of xylem vessel
transpiration occurs in leaves so water is continuously removed from the plant
reduction of effective pressure at the top of xylem vessel
water flows upwards from roots continuously
flow of water through plant: transpiration stream
tension produced to draw up water: transpiration pull

62. Transverse Transport of Water to Xylem
cytoplasm and cell sap have higher water potential than neighbouring cortical cells
epidermal cells gain water by osmosis
NOTE: some water may travel inwards along or between cell walls without entering cytoplasm or vacuole of each cortical cell
water travels by osmosis inwards from cell to cell

63. ~ End ~

64. Functions of Transport System in Angiosperms
carries water and mineral salts from the roots to the mesophyll cells of the leaves for photosynthesis by xylem

65. carries foods made in the leaves by
carries foods made in the leaves by photosynthesis to other cells of the plant by phloem
xylem and phloem are together called vascular bundles

67. Arrangement of Conducting Tissues in Angiosperms
in root
- close to central position in which xylem is found in the centre in a star-like arrangement and phloem lies between the radial arms of the xylem

69. - to resist the strong pulling force from the wind blowing the shoot
in stem
- close to the epidermis where the conducting tissues are arranged in a ring near the outside edge, with phloem lying outside and xylem inside

73. in leaves - to resist the strong bending force produced by wind
- vascular bundles are often called veins in which xylem lies above the phloem

74. Xylem consists of long tubular vessels
each vessel is made up of many dead cells which are hollow and joined end to end

76. the end walls of the cells have disappeared
the end walls of the cells have disappeared and so a long and open tube is formed
xylem vessels run from the root, through the stem and finally branch out into every leaf of the plant

77. xylem vessels contain no cytoplasm or nuclei
to prevent xylem from collapsing, they have thick cell walls made of cellulose and strengthened by rings of a woody substance called lignin

78. Phloem
made up of tube cells called sieve tubes which are living cells joined end to end by perforated horizontal walls called sieve plate
the perforations allow dissolved substances to flow through them so food made in the leaves can be carried to other parts of the plant

79. sieve tubes contain cytoplasm but no
sieve tubes contain cytoplasm but no nuclei and they do not have lignin in their cell walls
each sieve tube has a companion cell next to it. The companion cell does have a nucleus and contain many other organelles

81. Comparison between Sieve Tubes and Vessels
living cells
dead cells
smaller diameter
larger diameter
walls relatively thin, flexible, composed of cellulose
walls relatively thick, hard, strengthened by rings of lignin

82. Comparison between Sieve Tubes and Vessels
the lumens of mature cells are filled with cytoplasm
the lumens of mature cells are empty
end walls of adjacent sieve tubes from sieve plates
end walls of adjacent vessels cells break down

83. Upward Transportation of Water and Mineral Salts
root pressure
capillarity
by transpiration pull

84. Transpiration Pull
most of the water rising up in the xylem of the stem is pulled up by this
during transpiration, water is continually removed from the top of xylem vessels to supply cells in the leaves so pressure at the top of xylem reduces and water flows up

86. Transport of Organic Nutrients
translocation is the process of transporting the manufactured carbohydrates in photosynthesis via phloem from the leaves to other parts of the plant

88. ~ End ~