1

2 parent plantsingle cells

3 dish with nutrientscell masses

4 small plantsadult plants

5 They are identical to the parent plant.

6 What process does 1 the single plant cell undergo to form a mass of cells

7 2 How do the unspecialized cells give rise to a whole plant

Concepts of growth and development zygote growth ( 生長 ) development ( 發育 ) complex multicellular adult

9 Growth 14.1 Concepts of growth and development 1Cell division an irreversible increase in size and dry mass brought by: mitotic cell division increase in number

10 Growth 14.1 Concepts of growth and development 2Cell enlargement an irreversible increase in size and dry mass brought by: synthesis of new materials increase in size

11 Development 14.1 Concepts of growth and development an irreversible change in form and increase in complexity formation of specialized cells to carry out different functions brought by differentiation of cells

12 Development 14.1 Concepts of growth and development cells growth occurs at the same time tissues organs systems

13 Growth and development in humans 14.1 Concepts of growth and development Growth Cell division zygote first mitotic cell division daughter cells second mitotic division

14 Growth and development in humans 14.1 Concepts of growth and development Growth Cell division repeated divisions a ball of cells Cell enlargement

15 Growth and development in humans 14.1 Concepts of growth and development Development Cell differentiation differentiate red blood cells cardiac muscle cells nerve cells

16 Growth and development in humans 14.1 Concepts of growth and development Development similar cells group together tissues organs systems (increase in complexity)

17 1a Growth is the irreversible increase in and of an organism. sizedry mass 14.1 Concepts of growth and development

18 1b Development is the irreversible change in and the increase in of an organism. form complexity 14.1 Concepts of growth and development

19 2 Growth results from and. Mitotic cell division increases the number of cells and cell enlargement increases the of cells Concepts of growth and development cell division cell enlargement number size

20 process of forming cells to carry out different functions 3a Development results from differentiation of cells. differentiation specialized 14.1 Concepts of growth and development

21 3b Similar types of specialized cells group together to form, organs and Concepts of growth and development tissues systems organs

22 Growth and development in plants

23 Dicot vs Monocot Seeds

24 Seed Germination seedseedling

25 Seed Germination seedseedling dormancy active grow

26 dehydration Seed maturation involves dehydration

27 Water during seed development, dormancy and germination Seed germination

28 Water during seed development, dormancy and germination Seed germination food reserve water embryo

29 Water during seed development, dormancy and germination Seed germination food reserve water embryo

30 Water during seed development, dormancy and germination Seed germination food reserve water embryo

31 Seed (dicot) Germination

32 XY

33 c. In terms of the change in dry mass during seed germination (before leaves emerge), what kind of growth is demonstrated?

34 Where does growth and development take place in plants?

35 Regions of growth and development 14.2 Growth and development in plants growth only happens in meristems ( 分生組織 ) a group of undifferentiated cells

36 Regions of growth and development 14.2 Growth and development in plants growth only happens in meristems ( 分生組織 ) able to divide by mitotic cell division throughout the plant’s life apical meristem lateral meristem

Growth and development in plants Regions of growth and development apical meristem shoot tip root tip tips of roots and shoots increase in length primary growth ( 初生生長 )

Growth and development in plants Regions of growth and development lateral meristem periphery of stems and roots increase in thickness secondary growth ( 次生生長 )

Measurement of growth I record its height every day. Do you know how many parameters we can use to measure the growth of an organism?

40 1Size 14.3 Measurement of growth By measuring … a length or height suitable for organisms or structures which grow mainly by elongation e.g. length of root of a seedling

41 1Size 14.3 Measurement of growth By measuring … b surface area suitable for flat structures e.g. surface area of a leaf transparent grid paper

42 1Size 14.3 Measurement of growth By measuring … c volume suitable for structures with irregular shapes e.g. fruit change in volume = volume of pear

43 1Size 14.3 Measurement of growth Advantages organisms remain alive, allowing continuous measurement easy and convenient

44 1Size 14.3 Measurement of growth Disadvantage measured in one dimension, growth in other dimension is ignored e.g. shrub may grow laterally without any increase in height

45 2Fresh mass 14.3 Measurement of growth = total mass under normal conditions (including water)

46 2Fresh mass 14.3 Measurement of growth Advantages organisms remain alive, allow continuous measurement easy and convenient

47 2Fresh mass 14.3 Measurement of growth Disadvantage affected by water content, leads to great variation affected by environmental conditions and behaviour of organisms

48 3Dry mass 14.3 Measurement of growth = mass when all water is removed from the organism’s body = mass of organic matter present

49 3Dry mass 14.3 Measurement of growth oven slightly above 100°C constant mass is obtained

50 3Dry mass 14.3 Measurement of growth Advantage NotNot affected by water content of organisms which fluctuates a lot due to environmental conditions

51 3Dry mass 14.3 Measurement of growth Disadvantages large sample size is needed organisms are killed after measurement Cannot make continuous measurement

52 3Dry mass 14.3 Measurement of growth Disadvantages time-consuming, not suitable for large organisms

53 Parameter for measuring growth: size i.e. measuring length,, surface area and 14.3 Measurement of growth volume height

54 Advantage: The organism remains, so its growth can be measured continuously Easy and 14.3 Measurement of growth alive convenient Parameter for measuring growth: size

55 Disadvantage: Size is measured in dimension, growth in other dimension can / cannot be taken into account 14.3 Measurement of growth one Parameter for measuring growth: size

56 Parameter for measuring growth: fresh mass i.e. measuring mass with retained 14.3 Measurement of growth water

57 Advantage: The organism remains, so its growth can be measured continuously Easy and 14.3 Measurement of growth alive convenient Parameter for measuring growth: fresh mass

58 Disadvantage: Affected by which varies with different environmental conditions and behaviour of the organism 14.3 Measurement of growth water content behaviour Parameter for measuring growth: fresh mass

59 Parameter for measuring growth: dry mass i.e. measuring mass with removed 14.3 Measurement of growth water

60 Parameter for measuring growth: dry mass Advantage: An method to measure the amount of organic matter in an organism 14.3 Measurement of growth accurate

61 Disadvantage: The organism is, so its growth can / cannot be measured continuously A number of specimen is needed 14.3 Measurement of growth killed large Parameter for measuring growth: dry mass

62 Disadvantage: Time-consuming Not suitable for organisms 14.3 Measurement of growth large Parameter for measuring growth: dry mass

Growth curves I have recorded the length of the main roots of young seedlings for a week. How should I present the data? Use a growth curve.

64 S-shaped growth curve

65 Growth curves of annual plants 14.4 Growth curves annual plant ( 一年生植物 ) lives for only one growing season growth curve has 3 stages and an S-shape

66 Growth curves of annual plants Stage 1 stage 50 time (weeks) Stored food is broken down to provide energy for growth dry mass decreases dry mass (g) 14.4 Growth curves

67 Growth curves of annual plants Stage 2 stage 50 time (weeks) Green leaves are formed to make food by photosynthesis dry mass increases 2 dry mass (g) 14.4 Growth curves

68 Growth curves of annual plants Stage 2 stage 50 time (weeks) Green leaves are formed to make food by photosynthesis dry mass increases 2 dry mass (g) 14.4 Growth curves rate of photosynthesis > rate of respiration food production > consumption

69 Growth curves of annual plants Stage 3 stage 50 time (weeks) Dispersal of fruits and seeds dry mass decreases 23 death dry mass (g) 14.4 Growth curves

70 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) foetal growth birth

71 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) infancy ( 嬰兒期 ) 3 rapid growth

72 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) childhood ( 兒童期 ) 313 growth slows down

73 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) adolescence ( 青年期 ) 313 rapid growth 18

74 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) adult stage ( 成年期 ) height remains steady 65

75 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) adult stage ( 成年期 ) cell division still occurs to replace worn out cells 65

76 Growth curves of humans 14.4 Growth curves 0 body weight / height age (years) old stage ( 衰老期 ) death negative growth

77 Growth rates of different body parts 14.4 Growth curves Different body parts also grow at different times and different rates.

78 age (years) Growth rates of different body parts 14.4 Growth curves relative growth rate (%) whole body

79 Our body proportion changes as we grow

80

81 age (years) Growth rates of different body parts 14.4 Growth curves relative growth rate (%) whole body brain rapid growth during infancy and early childhood

82 age (years) Growth rates of different body parts 14.4 Growth curves relative growth rate (%) whole body reproductive organs rapid growth at puberty brain

83 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs5 yrs13 yrs22 yrs head grows rapidly at early stage

84 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs relative size decreases with age 5 yrs

85 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs limbs grow slowly at early stage 5 yrs

86 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs relative size increases with age 5 yrs

87 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs trunk grows at a rate proportional to 5 yrs

88 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs the rate of whole body 5 yrs

89 Growth rates of different body parts 14.4 Growth curves 9-week foetus new- born 2 yrs13 yrs22 yrs relative size remains the same 5 yrs

Growth rates of different sexes 14.4 Growth curves body mass (kg) age (years) girls boys different rates during adolescence

Growth rates of different sexes 14.4 Growth curves body mass (kg) age (years) girls reach puberty earlier

Growth rates of different sexes 14.4 Growth curves body mass (kg) age (years) girls reach puberty earlier boys grow faster than girls at adolescence

Growth rates of different sexes 14.4 Growth curves body mass (kg) age (years) girls grow faster than boys boys boys grow faster than girls girls reach puberty earlier girls

94 Different kinds of growth curves Absolute growth Absolute growth rate Relative growth rate

95 Growth patterns Isometric Growth

96 Growth patterns Allometric Growth – growth with a change in relative proportion of body parts

97 Growth patterns Limited vs unlimited Growth in human age height

98 Growth patterns catfish Limited vs Unlimited Growth in some fish

99 Growth curve in annual plants Sunflower plant in bloom

100 Growth curve in annual plants

101 Growth curve in annual plants Seed germination Rapid vegetative growth flower, seed, fruit formation seed dispersal and death

102 Growth patterns Limited vs unlimited growth in perennial plants

103 Growth curve in perennial plants

104 Dry mass during the early stage of germination because the stored food is broken down to provide energy for growth. 1 Growth stages of annual plants: broken down decreases 14.4 Growth curves

105 Dry mass after green leaves are produced because food production is faster than food consumption. 1 Growth stages of annual plants: increases 14.4 Growth curves green leaves

106 Dry mass when the plant disperses its fruits and seeds. 1 Growth stages of annual plants: decreases 14.4 Growth curves seeds

107 2 Growth occurs in parts of the human body. all 14.4 Growth curves

108 Growth occurs during infancy. 3 Growth stages in humans: rapidly 14.4 Growth curves

109 Growth then during childhood and becomes again in adolescence. 3 Growth stages in humans: slows down rapid 14.4 Growth curves

110 A person reaches the maximum size in. 3 Growth stages in humans: adulthood 14.4 Growth curves

111 Growth becomes during the old stage. 3 Growth stages in humans: negative 14.4 Growth curves

112 4 Relative sizes of different body parts change with age because they have different growth rates. different 14.4 Growth curves

113 5 Girls enter puberty than boys, therefore girls have a faster growth rate than boys during the early stage of adolescence. earlier 14.4 Growth curves

Growth and development in plants I still don’t understand ‘growth’ and ‘development’. Let’s discuss the situation in plants.

115 Seed germination 14.2 Growth and development in plants process by which a seed grows and develops into a seedling germination ( 萌發 )

116 Seed germination 14.2 Growth and development in plants Day 2 radicle seed coat water The radicle emerges. mung bean seed

117 Seed germination 14.2 Growth and development in plants seed cut open

118 Seed germination 14.2 Growth and development in plants 1 Seed absorbs water through the micropyle and the seed coat breaks. Day 2

119 Seed germination 14.2 Growth and development in plants 2 Insoluble food in cotyledons is converted to soluble form by enzymes. Day 2

120 Seed germination 14.2 Growth and development in plants 3 Soluble food is transported to the plumule and radicle for growth and development. Day 2

121 Seed germination 14.2 Growth and development in plants Day 3 Root hairs increase the surface area for absorbing water and minerals. root hairs radicle

122 Seed germination 14.2 Growth and development in plants Day 4 The hypocotyl elongates and brings the cotyledons up. hooked hypocotyl ( 下胚軸 ) plumule tip protected by cotyledons

123 Seed germination 14.2 Growth and development in plants Day 5 The hypocotyl straightens. hypocotyl

124 Seed germination 14.2 Growth and development in plants Day 5 The cotyledons carry out photosynthesis for a few days. hypocotyl cotyledons turn green

125 Seed germination 14.2 Growth and development in plants Day 6 Young leaves develop to make food by photosynthesis. Cotyledons fall off. young leaves cotyledons

126 Conditions for seed germination 14.2 Growth and development in plants i)Water a softens seed coat and makes cotyledons swell seed coat breaks, radicle can emerge

127 Conditions for seed germination 14.2 Growth and development in plants b activates enzymes help convert insoluble food reserves into simpler and soluble forms for growth i)Water

128 Conditions for seed germination 14.2 Growth and development in plants c acts as a solvent transports soluble food to growing regions i)Water

129 Conditions for seed germination 14.2 Growth and development in plants ii) Warmth allows enzymes to work effectively

130 Conditions for seed germination 14.2 Growth and development in plants iii) Oxygen necessary for respiration to provide energy for growth

131 Two centres of activity in seed germination

132 Regions of growth and development 14.2 Growth and development in plants growth only happens in meristems ( 分生組織 ) a group of undifferentiated cells

133 Regions of growth and development 14.2 Growth and development in plants growth only happens in meristems ( 分生組織 ) able to divide by mitotic cell division throughout the plant’s life apical meristem lateral meristem

Growth and development in plants Regions of growth and development apical meristem shoot tip root tip tips of roots and shoots increase in length primary growth ( 初生生長 )

Growth and development in plants Regions of growth and development lateral meristem periphery of stems and roots increase in thickness secondary growth ( 次生生長 )

136 At the root tip 14.2 Growth and development in plants region of differentiation ( 分化區 ) region of elongation ( 延長區 ) region of cell division ( 細胞分裂區 )

137 At the root tip 14.2 Growth and development in plants produces new cells by mitotic cell division region of cell division apical meristem root cap ( 根冠 ) protected by root cap

138 At the root tip 14.2 Growth and development in plants region of cell division dense cytoplasm (no vacuole) nucleus

139 At the root tip 14.2 Growth and development in plants cells come from region of cell division region of elongation cells enlarge by taking in water by osmosis and forming small vacuoles

140 At the root tip 14.2 Growth and development in plants region of elongation small vacuole thin cell wall

141 At the root tip 14.2 Growth and development in plants small vacuoles fuse to form large vacuoles region of differentiation cellulose fibres are made and added to cell walls

142 At the root tip 14.2 Growth and development in plants cell walls become thicker and more rigid region of differentiation cells differentiate to perform specific functions

143 At the root tip 14.2 Growth and development in plants region of differentiation xylem old root hair young root hair larger vacuole thicker cell wall

144 At the root tip 14.2 Growth and development in plants

145 Increase in length of root tip is mainly due to increase in number of cells.  14.2 Growth and development in plants

146 It is mainly due to elongation of cells Growth and development in plants

147 At the shoot tip 14.2 Growth and development in plants region of cell division region of elongation region of differentiation young leaf apical meristem

148 At the shoot tip 14.2 Growth and development in plants

149 At the periphery of stems and roots 14.2 Growth and development in plants lateral meristem found between xylem and phloem in woody plants new cells differentiate into secondary xylem and phloem

150 lateral meristem (cambium)between xylem and phloem

151 At the periphery of stems and roots 14.2 Growth and development in plants epidermis primary xylem primary phloem cortex direction of growth lateral meristem

152 lateral meristem form a ring of dividing tissue at the periphery of a stem lateral meristem

153 At the periphery of stems and roots 14.2 Growth and development in plants increase in thickness

154 At the periphery of stems and roots 14.2 Growth and development in plants increase in thickness secondary xylem ( 次生木質部 ) pushed inwards and becomes wood secondary phloem ( 次生韌皮部 )

155 At the periphery of stems and roots 14.2 Growth and development in plants years later … annual ring ( 年輪 )

156 First year secondary growth

157 Spring wood and autumn wood

158

159 Primary & Secondary growth in a woody stem

160 A Lenticel on bark

161 Seed absorbs and swells. Stored food in the is converted to soluble form for the growth of the plumule and radicle Growth and development in plants 1 Major processes in seed germination: water cotyledons

162 Root hairs develop from the radicle. They absorb water and minerals from the soil Growth and development in plants 1 Major processes in seed germination: Root hairs

163 The grows out of the soil. The cotyledons become and carry out photosynthesis Growth and development in plants hypocotyl green 1 Major processes in seed germination:

164 The plumule forms young to make food Growth and development in plants leaves 1 Major processes in seed germination:

Growth and development in plants 2, and are needed for seeds to germinate. Waterwarmthoxygen

Growth and development in plants 3 Growth occurs in at the tips of roots and shoots and lateral at the periphery of stems and roots. apical meristem lateral meristem

Growth and development in plants 4 Primary growth increases the length of a plant while secondary growth increases the of the stems and roots. length thickness

Growth and development in plants 5a Cells in region of cell division divide by to produce new cells. mitotic cell division

Growth and development in plants 5b Cells in region of elongation enlarge by taking in water. enlarge

Growth and development in plants 5c Cells in region of differentiation specialize to perform particular functions. functions

171 What process does the single plant cell undergo to form a mass of cells? 1 A single plant cell divides repeatedly by mitotic cell division to form a mass of cells.

172 How do the unspecialized cells give rise to a whole plant? 2 Through cell division, cell enlargement and cell differentiation, the unspecialized cells develop into a whole plant with specialized organs like leaves, stems and roots.

173 irreversible increase in resulted from Growth irreversible increase in cell division cell differentiation size or dry mass Development cell enlargement complexity

174 can be measured by the change in size Growth fresh mass dry mass

175 start from in humans occur in in plants germination GrowthDevelopment occur in root tip shoot tip periphery of stems & roots whole body