http kalviamuthu blogspot com Learning Objectives At end
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Learning Objectives At end of this unit, students will be able to understand : § Various physiological activities of plants. § § § Plants also show movements. Tropic and nastic movements in plants Plants feed the entire world Types of transpiration Macro and micro nutrients required for the plants § Gaseous exchange during photosynthesis and respiration in plants. ����� http: //kalviamuthu. blogspot. com
Why is this unit here? 1. It is an eye opener on plant life processes like photosynthesis, transpiration, respiration, nutrition etc. , 2. It is an interdisciplinary experimental and lab based field of science. 3. It is the study of plants as machines. 4. We can observe the life processes of plants in relation to their external environmental conditions. 5. Studies on discovery of photosynthesis and tropic movements instigates research interests in students. ����� http: //kalviamuthu. blogspot. com
Living World of Plants - Plant Physiology Introduction. . . ����� http: //kalviamuthu. blogspot. com
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Living World of Plants - Plant Physiology Do plants show movement? ����� http: //kalviamuthu. blogspot. com
Living World of Plants - Plant Physiology 6. 1 Do they move on their own accord? 1. Do the plants have spontaneous movements without external agency? 2. Do they breathe? ����� http: //kalviamuthu. blogspot. com
Living World of Plants - Plant Physiology ����� http: //kalviamuthu. blogspot. com
6. 2. Do plants move? ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology 6. 3. Do plants actually sense light? Structure of a Maize seed Once germinated, embryo structure of Maize seed sends primary root downward &����� pushes primary shoot to soil. ����� http: //kalviamuthu. blogspot. com
6. 3 Do Plants Actually Sense Light? Living World of Plants - Plant Physiology Darwin’s experiment on Phototropism - 1880 Conclusion: Some “Influence” is transmitted from the tip to the more basal regions of the shoot thereby regulating the growth and inducing curvature. ����� http: //kalviamuthu. blogspot. com
Peter Boysen – Jensen’s Experiment (Danish Botanist - 1913) Exp. No. Experiment Observation 1. He removed the Coleoptile The plant growth stopped. 2. He inserted a piece of agar and placed the coleoptile on it’s top. The plant was able to curve towards the light. (Chemical was predicted to be water soluble 3. He replaced the agar block with butter. The water soluble chemical did not dissolve in butter. Conclusion: - Water soluble “Influence” – identified as Auxin (Plant hormone) - In response to light, auxin elongates the cells on the dark side of ����� the stem so that the plant literally bends towards the light source. http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology Bending of stem towards light ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology 6. 4. Types of Tropism in Plants Types - based on the external stimulus: 1. Phototropism/heliotropism: Light – Shoots, leaves, flowers 2. Geotropism/Gravitropism : Gravity – Roots. 3. Hydrotropism : Water – Roots 4. Thigmotropism : Touch – Climbing Vines 5. Chemotropism : Chemicals – Pollen tube Types - based on the direction: 1. Positive: Movement towards the signal - 2. Negative: Movement away from the signal Shoots – positive phototropism, negative geotropism ����� http: //kalviamuthu. blogspot. com Roots – negative phototropism, positive geotropism
Living World of Plants – Plant Physiology Positive phototropism (Negative Geotropism) Positive Geotropism Negative Geotropism ����� http: //kalviamuthu. blogspot. com
Thigmotropism Brunnichia ovata Chemotropism Pollen germination ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology Activity 1 - Roots grow down and Shoots grow up 1. Take 4 or 5 earthen cups or small pots, ( hole at the bottom) 1. Fill with soil 2. Add cow dung 3. Label the pots as A, B, C , D & E 4. Green gram seeds - water 5. Select a shoot of the same height (each cup). 6. Remove remaining. ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology Roots grow down and Shoots grow up. . . Step 2 1. 2. 3. 4. 5. Take a shoe box. Cut a window (1 x 1 cm) on one side Cover all cups, except A, with the box. Openings face different directions. Keep cups in sun light. ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology Roots grow down and Shoots grow up 1. Wait for 3 to 4 days 2. Remove the box and look at the plants 3. Compile the results and discuss Questions for observation and inference 1. Are the plants tilted? 2. To which side are they tilted? 3. With the opening facing different directions, did all the plants tilt the same direction? ����� Conclusion : Plants growhttp: //kalviamuthu. blogspot. com towards the sunlight.
Activity 2: Experiment to demonstrate Phototropism 1. Take soaked pea seeds 2. seeds germinate 3. Cover the seedling – box (opening on one side. ) 4. Observe growth of the stem. ����� http: //kalviamuthu. blogspot. com
Experiment: Water or gravity? 1. Primary shoot goes up / primary root goes down 2. What is principally responsible for the direction of the growth of the primary root? It is gravity or water? ����� http: //kalviamuthu. blogspot. com
Living World of Plants – Plant Physiology Activity 3 – Clinostat Experiment to demonstrate Geotropism 1. 2 clinostats with potted plant (horizontal position. ) 2. Rotate one 3. Other stationary Observation Stationary clinostat : Shoot bends upwards (negative geotropism) Root bends downwards (positive geotropism) Rotating Clinostat : no bending of shoot/root Gravitational stimulus is not unilateral when rotated ����� http: //kalviamuthu. blogspot. com
6. 5 More to movement than growth movements Types of movements: 1. Thigmonasty or Seismonasty : Touch Mimosa pudica(Touch-me-not) Dionaea muscipula(Venus Flytrap) ����� http: //kalviamuthu. blogspot. com
2. Nictinasty – darkness Eg Leucaena leucocephala 3. Thermonasty - temperature Eg : Tulipa sp ����� http: //kalviamuthu. blogspot. com
4. Photonasty – light intensity Photonasty in Taraxacum officinale (Dandelion) Night Day Photonasty (Samanea saman) Photonasty in Ipomoea alba (Moon flower) Day Night ����� http: //kalviamuthu. blogspot. com
Advantages of tropic and nastic movements 1. Root – downwards - water and minerals 2. Stem - upward a) sunlight b) display flowers (pollinators) c) spreading seeds Table 1 : Differences between tropic and nastic movements S. No Tropic movements Nastic movements 1. Unidirectional response to stimulus Non-directional response to stimulus 2. Growth dependent movement Growth independent movement 3. Permanent and irreversible Temporary and reversible 4. Found in all parts Only a few specialized plants 5. Slow action Immediate action ����� http: //kalviamuthu. blogspot. com
Photosynthesis 6. 6 What is Photosynthesis? Photo Synthesis Photosynthesis Light Energy Green plants - Light - To build - Building up with the help of light - Chemical energy ����� -����� Autotrophic (Photosynthesis) http: //kalviamuthu. blogspot. com
Overall equation of photosynthesis End product - Glucose - Starch(Stored) Take in - Carbon dioxide Oxygen - to carry on cellular respiration ����� http: //kalviamuthu. blogspot. com
Jan Baptist van Helmont’s experiment v Banyan tree - Sapling – huge tree. v How did it gain mass ? v Jan Baptist van Helmont (Belgian Scientist ) – 1648 v Soil – dried – measured - 90. 9 kg – porous container. v Willow tree sapling - 2. 3 kg – container closed v 5 years- only water - tree v Uprooted – 77 kg , soil → 90. 8 kg v Gain in plant’s weight → 77. 0 -2. 3 = 74. 7 kg (5 years) v Loss in soil weight → 90. 9 -90. 8 = 0. 1 kg ����� http: //kalviamuthu. blogspot. com
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6. 6. 1 What else is needed for photosynthesis Things needed for Photosynthesis 1. Chorophyll 2. Water 3. Carbon dioxide 4. Light ����� http: //kalviamuthu. blogspot. com
Experiment: Chlorophyll is essential for photosynthesis Aim: Materials Required : croton plant , boiling water , Alcohol , Iodine solution. Procedure : ü Destarch the plant (24 hrs) ü Pluck a variegated leaf ü Draw (shape & patches of chlorophyll) ü Immerse (boiling water and alcohol) ü Iodine test Observation: Green patches turn blueblack Other portions remain colorless ����� Conclusion: http: //kalviamuthu. blogspot. com
Experiment: Sunlight is necessary for photosynthesis Aim: Materials Required : potted plant, black paper, boiling water, Alcohol , Iodine solution. Procedure : ü Destarch plant (24 hours) ü Cover a leaf (thin black paper) ü Sunlight (4 -6 hrs) ü Pluck covered leaf. ü Immerse in boiling water and alcohol ü Iodine test Observation: Covered part did not turn blue. Other portions turns blue-black. Conclusion: ����� http: //kalviamuthu. blogspot. com
6. 6. 2 Exchange of Gas Roots absorb water Ø How does the plant get air ? Ø Leaves – tiny pores – Stomata Ø Microscopic Ø Inhale and exhale – continuously Stomata Ø ����� http: //kalviamuthu. blogspot. com
6. 6. 3 Transpiration Ø Definition: Ø Types: 1. Stomatal transpiration : most dominant – 90 to 95% 2. Cuticular Transpiration : Cuticle 3. Lenticular transpiration : Lenticels ����� http: //kalviamuthu. blogspot. com
Experiment - 1 Ø Ø Ø Ø Take a plant Tie a plastic bag over a leaf Place in light See water condensing inside Water is let out by the leaves Stomata – Guard cells regulate transpiration by opening and closing of stoma. 0. 1 % of absorbed water – to produce carbohydrate ����� http: //kalviamuthu. blogspot. com
Activity 4 Ø To observe the impression of Stomata Ø Nail polish (lower surface) -peeled off Ø Observe cells and stomata under microscope - Hot weather - more water evaporates. - Stomata begin to closes - Lessens evaporation - Dry land desert plants adapt to conserve water ����� http: //kalviamuthu. blogspot. com
Transpiration is a necessary evil: Discuss Ø Creates a pull in leaf & stem Ø Absorption force in roots Ø Takes more water Ø Needs continuous supply of minerals Ø Regulates temperature ����� http: //kalviamuthu. blogspot. com
6. 6. 4 Macronutrients and Micronutrients for plants • Macronutrients: • Required In substantial quantity • C, H, O, N, P, Ca, Mg, S and P. • Micronutrients: • Required in minute quantities • Fe, Mn, Cu, B, Mo, Cl, Si, Co and Zn. • Circulated along with water ����� http: //kalviamuthu. blogspot. com
Food Chain: link between plants , animals and microorgan Plants – primary producers Herbivores – consume the plants Carnivores – eat animals that graze and gather energy from plants Decomposers – microorganisms ����� http: //kalviamuthu. blogspot. com
6. 6. 6 RESPIRATION: q plants too respire q take in oxygen and give out carbon dioxide q goes on 24 hours (day and night) q in photosynthesis, take in carbon dioxide and give out oxygen q photosynthesis occurs only during day time ����� http: //kalviamuthu. blogspot. com
MIND MAPPING TROPIC MOVEMENTS NASTIC MOVEMENTS PHOTOSYSNTHESIS TRANSPIRATION PLANT PHYSIOLOGY RESPIRATION ����� http: //kalviamuthu. blogspot. com FOOD CHAIN MACRO & MICRO NUTRIENTS
Info bits 1. Pg 136 : tropism, tropic and nastic movements 2. Pg. 137: pneumatophores 3. Pg 140 : photosynthesis – oxygen into ozone ozone protects mother earth 4. Pg 142 : structural resemblance between chlorophyll and haemoglobin. 5. Pg 145 : 1% of absorbed water is used & 99% lost – Maize plant (55 gallons of water) ����� http: //kalviamuthu. blogspot. com
More to know. . . 1. Pg 134 : Desmodium gyrans (Indian telegraph plant) – compound leaf – dancing plant – Jagadish Chandra Bose 2. Pg 141 : Helmont and Priestley’s Experiments 3. Pg 144 : Chemical analysis of photosynthesis: 100 g + 260 g (H 2 O) → 180 g (CO 2) (CH 2 O) n ����� http: //kalviamuthu. blogspot. com + 180 g (O 2)
Do You know ? • 1. Pg. 134: Mimosa pudica – thotta surungi Desmodium gyrans – thozhu kanni 2. Pg. 138: Insectivorous plants– Venus fly trap- fastest known nastic movements 3. Pg. 143: Sea Slug – Elysia chlorotica – consumes Vaucheria litorea 4. Pg. 143: Organisms live deep in ocean do photosynthesis – Green sulphur bacteria (2400 meters deep) – Mexico ocean 5. Pg. 145 : Guard cells can’t photosynthesize. Why? 6. Pg. 146 : Conifers have a pyramidal shape – advantages. 7. Pg. 146 : Why do we get more rainfall in amazon? 8. Pg. 146 : Do the Insects trap solar energy? ����� Vespa orientalis (oriental hornets) – by Tel Aviv University Scientists http: //kalviamuthu. blogspot. com
s Activitie • Pg 134 : Roots grow down and shoots grow up • Pg 136 : Experiment to demonstrate phototropism • Pg 137 : Experiment to demonstrate geotropism • Pg 145 : Experiment to observe Impression of stomata ����� http: //kalviamuthu. blogspot. com
ments Experi • Pg. 137: Water or gravity • Pg. 142 : Experiment to demonstrate that chlorophyll is essential for photosynthesis • Pg. 143 : Experiment to demonstrate sunlight is necessary for photosynthesis • Pg. 144 : Transpiration (plastic bag covering) ����� http: //kalviamuthu. blogspot. com
Exercise… I. Multiple Choice Questions(MCQs) 1. A big tree falls in a forest but it’s roots are still in contact with the soil. The branches of this fallen tree straight up. This happens in response to ____. a) Water and light. b) Water and minerals. c) Gravity and water. d) Light and gravity. II. State whether the following statements are true or false. If false, write the correct statement 2. When the weather is hot, water evaporates lesser which is due to opening of stomata III. Answer in a word or two 3. Observe the given picture. a. Identify this plant. What type of special movement is shown by this plant ? ����� b. What are the other movements seen in this plant ? http: //kalviamuthu. blogspot. com
…Exercise IV. Answer the following in one or two sentences 4. Photosynthesis converts energy X into energy Y. a. What are X and Y? b. Green plants are autotrophic in their mode of nutrition. Why ? V. Answer in detail 5. Design an experiment to demonstrate hydrotropism. ����� http: //kalviamuthu. blogspot. com
Work Book… I. Multiple choice questions 1. The root of the plant is _____ i) Positively phototropic but negatively geotropic ii) Positively geotropic but negatively phototropic iii) Negatively phototropic but positively hydrotropic iv) Negatively hydrotropic but positively phototropic a. (i) and (ii) b. (ii) and (iii) c. (iii) and (iv) d. (i) and (iv) II. Fill in the blanks 2. Plants utilize only _______ % of the absorbed water for photosynthesis and the other activities. ����� http: //kalviamuthu. blogspot. com
. . . Work Book… III. State whether the following statements are true or false. If false write the correct statement: 3. The petals of the moon flower open up in the morning and closes in the evening. This is called photonasty. IV. Answer in a word or two 4. Study the picture given below and then complete the table by putting a plus (+) if the shoot or root grows towards the stimulus and a minus (-) if It grows away from it. Stimulus Light Gravity Shoot + - Root ? + V. Fill in the blanks Sun Light 5. 6 CO 2 + ______ ____ + 6 O 2 ↑ ����� http: //kalviamuthu. blogspot. com Chlorophyll
V. Answer in one or two sentences: 5) A potted plant is kept horizontally for a considerable time. The three positions of the part A and B of the potted plant are shown in the following figures : (i) (ii) (iii) a) Which figure shows the correct position taken by parts A and B of the plant ? b) What type of phenomenon is exhibited by the figure by (A) in the figure (ii) ? VI ����� http: //kalviamuthu. blogspot. com
VI. Assertion and Reason 6. Assertion (A): If the plant part moves in the direction of gravity, it is called positive geotropism. Reason (R) : Stem shows positive geotropism a) A and R are incorrect b) A is incorrect , R is correct c) A is correct , R is incorrect d) Both A and R are correct 7. Assertion (A): The loss of excess water from the aerial parts of the plant in the form of water vapour is known as transpiration. Reason (R) : Stomata of the leaf perform transpiration. a) A and R are incorrect b) A is incorrect , R is correct c) A is correct , R is incorrect d) Both A and R are correct ����� http: //kalviamuthu. blogspot. com
VII. Higher Order Thinking Questions (HOTS) 8. There are 3 plants: A, B and C. The flowers of A open their petals in bright light during the day but close them when it gets dark at night. On the other hand, the flowers of plant B open their petals at night but close them during the day when there is bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object. a) Name the phenomenon shown by the flowers of the plant A and B. b) Name one flower each which behaves like flowers of plant A and B. c) Name the phenomenon exhibited by the leaves of plant C. d) Name a plant whose leaves behave like those of plant C. 9. While conducting experiments to study the effects of various stimuli on the plants , it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bends away from third stimulus C. The stem of the plant X however bends away from Stimulus A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to too much weight of that with earth. Keeping these points in mind answer the following questions: a) What could be stimulus A? ����� http: //kalviamuthu. blogspot. com b) Name the stimulus seen in B. C) What could be stimulus C?
10. An Organism A which cannot move from one place to another makes a simple food B from the substances C and D available in the environment. This food is made in the presence of green coloured substance E present in organs F in the presence of light energy in a process called G. Some of the simple food B also gets converted into complex food H for storage purposes. This food gives blue-black colour with iodine solution. a) What is (i) Organism A (ii) Food B and Food H b) What are C and D? c) Name (i) Green pigments E (ii) Organ F d) What is the process G? 11) Imagine that a student A studied the importance of certain factors in photosynthesis. He took a potted plant and kept in dark for over 24 hours. In the early hours of next morning he covered one of the leaves with dark paper in the centre only. Then he placed the plant in the sun light for a few hours and tested the leaf which was covered with black paper for starch. a) What aspect of photosynthesis was being investigated? b) Why was the plant kept in the dark before the experiment? c) How will you prove that starch is present in the leaves? ����� d) What are the other raw materials for photosynthesis? http: //kalviamuthu. blogspot. com
GROUP GAME: 1… S: NO Movement Stimulus Plant part 1 Photosynthesis Light Shoot 2 Geotropism Gravity Root 3 Hydrotropism Water Root 4 Thigmotropism Touch Climbing vines 5 Chemotropism ����� Chemicals Pollen tube http: //kalviamuthu. blogspot. com Pcture
…GROUP GAME: 1 S: NO Movement Stimulus Plant part Pcture 6 Thigmonasty Darkness Leaves 7 8 9 Nictinasty Thermonasty Photonasty Darkness Temperature Light Leaves Flowers ����� http: //kalviamuthu. blogspot. com
GROUP GAME : 2 (MACROS & MICROS) 1 Boron B Micronutrient 2 Calcium Ca Macronutrient 3 Chlorine Cl Micronutrient 4 Cobalt Co Micronutrient 5 Potassium K Macronutrient 6 Hydrogen H Macronutrient 7 Magnesium Mg Macronutrient 8 Silicon Si Micronutrient ����� http: //kalviamuthu. blogspot. com
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