TOPICS PLANT PHYSIOLOGY B 4 WATER RELATIONS OF PLANTS (10 MARKS) B 5 BIOENERGETICS (12 MARKS) B 6 GROWTH AND GROWTH REGULATORS IN PLANTS (05MARKS)
B.4 WATER RELATIONS OF PLANTS (10 marks)
IMBIBITION,DIFFUSION,OSMOSIS ABSORPTION OF WATER LATERAL CONDUCTION OF WATER ASCENT OF SAP LOSS OF WATER- TRANSPIRATION GUTTATION TRANSLOCATION OF ORGANIC SOLUTES
B.4 WATER RELATIONS OF PLANTS (10 marks) 1 mark questions 2 marks questions 5 marks questions
1 MARK QUESTIONS Q. Define Imbibition. Ans: Adsorption of water by hydrophilic substances like cellulose, gum etc.,
Q. Define wall pressure Ans: Pressure exerted by the cell wall on the protoplasm p against turgor pressure
A plant cell
Q. Name the phenomenon of shrinking of protoplast when the Rheo leaf is placed in sodium chloride solution. Ans: Exosmosis
Q. What is vein loading? Ans: Vein loading is transfer of food from mesophyll cells to sieve tube cells through parenchyma cells against concentration gradient.
Q. What is the significance of CoCl 2 experiment? Ans: It reveals unequal transpiration in a dorsiventral leaf.
Q. Define guttation. Ans: Guttation is the loss of water in the form of droplets through leaf tip / vein endings in herbaceous plants during warm humid nights.
L Sof leaf
Q. Level of mercury rises in Ans: the capillary tube of simple potometer. t Why? Transpiration pull
Give reasons (One mark each): Q. It is difficult to open and Ans: close wooden shutters during rainy season. Imbibition
Q. Turgidity or flaccidity Ans: of guard cells affect the rate of transpiration. Guard cells enclose stomata. Decrease in the osmotic concentration brings about transpiration
Q. Potato osmoscope is a physiological set up. Ans: It involves living cells
Q. Fresh grapes shrink Ans: in salt solution. Exosmosis
Q. Excessive use of Ans: chemical fertilizers results in wilting of plants. Exosmosis
Q. As the wind blows, rate of ascent of sap increases Ans: Wind carries away the moisture and increases the rate of transpiration
Q. When osmotic concentration Ans: increases in guard cells, the stomata opens Increased osmotic concentration expands the guard cells.
Q. Girdling experiment cannot be performed in sugar cane plants. Ans: Phloem does not occur in a ring.
Q. In cobalt chloride paper experiment, the lower strip of paper p turns pink faster than the upper strip. Why? Ans: Unequal transpiration
2 marks each: Q. Mention any two Ans: significances of diffusion in plants 1. Exchange of gases 2. Absorption and conduction of minerals
Q. Write any four significance of osmosis. 1. Turgidity of cells 2. Absorption of water 3. Cell to cell conduction of water 4. Regulation of stomata
Q. Write any four differences between transpiration and guttation. Transpiration Guttation 1. Day time 1. Warm humid nights 2. Vapour 3. Pure 4. More water 2. Droplets 3. Dissolved minerals 4. Less water
Q. What are antitranspirants? Name any two antitranspirants. Ans: Substances which reduce or stop transpiration are called antitranspirants. Physical- liquid wax. Physiological- Abscissic acid
Q. Mention four factors affecting transpiration. Ans: 1. Wind 2. Temperature 3. Soil water 4. Humidity
(5 mark questions) Q. TCT theory
Q. List and explain the different external factors affecting the rate of transpiration.
Q. Describe Steward s Starch hydrolysis theory of stomatal movement.
Q. Proton ion concept
Q. Explain Munch s mass flow hypothesis.
Practicals: Q. Simple potometer
Q. Unequal transpiration ti
B5 BIOENERGETICS (12 MARKS)
TOPICS: ATP PHOTOSYNTHESIS RESPIRATION
1 mark questions 2 marks questions 5 marks questions
Q. Name the energy currency of the cell. Ans: ATP (Adenosine Tri Phosphate)
Q. What is the significance of chromatography? h Ans: It reveals that leaf contains various pigments like Chlorophyll-a, chlorophyll-b, xathophyll and carotenes.
Q. Name the first stable intermediate compound formed in Calvin s cycle (C 3 pathway) Ans: Phospho Glyceric Acid (PGA) (3C)
Q. State Blackman s law of limiting factors. Ans: When a reaction is conditioned as to its rapidity by a number of separate factors, the rate of the reaction is decided by the pace of slowest factor.
Q. What is solarization? Ans: Breakdown of photosynthetic pigments under the influence of high intensity sunlight.
Q. Name the phase that is common for both aerobic and anaerobic respiration. Ans: Glycolysis / EMP pathway
Q. In which h cell organelle, Kreb s cycle occurs? Ans: Mitochondria
Q. Where does terminal oxidation take place in mitochondria? Ans: Racker s particles / elementary particles
Q. Define respiratory yquotient. Ans: The ratio of carbon dioxide released to the oxygen consumed during respiration.
Q. In germinating gram seeds that respire aerobically, value of RQ is less than one. Why? Ans: The amount of carbon dioxide released is equal to the oxygen consumed.
Q. What is Pasteur effect? Ans: The ability of yeast cells to switch over from anaerobic to aerobic respiration depending on the availability of oxygen.
Q. The addition of lime water to water in an experimental setup with aquatic plants decreases the amount of oxygen released. Why? Ans: Lime water combines with carbon dioxide and affects photosynthesis.
Q. Name the gas liberated in Ganong s respiroscope. Ans: Carbon dioxide
Give reasons (One mark each): Q. Some bacteria exhibit photosynthesis but they do not produce oxygen. Ans: They use H 2 S instead of H 2 O
Q. Carotenoid and xanthophyll are called accessory photosynthetic pigments Ans: They can only trap sunlight but cannot convert it to ATP.
Q. For NCPP,,photolysis of water is must Ans: Hydrogen released during photolysis of water is used to form NADPH 2
Q. Plants are lungs of nature Ans: They release oxygen
Q. CAM plants close their stomata during daytime. Ans: They fix carbon dioxide in the previous night.
Q. Very high temperature decreases the rate of photosynthesis. Ans: High temperature influence closure of stomata.
Q. RQ value of glucose is one. Ans: The amount of carbon dioxide released is equal to the amount of oxygen consumed.
(2 marks each) Q. Draw a labelled sketch of T S of chloroplast.
Q. Write the schematic representation of CPP.
(5 MARKS QUESTIONS)
Q. Write the schematic representation of C 3 pathway.
Q. External factors of photosynthesis Ans: Sunlight Temperature Carbon dioxide id Water
Q. Write the schematic representation of EMP pathway.
Q. Write the schematic representation of Kreb s cycle (Citric acid cycle) with preparatory phase
Q. Factors affecting respiration Temperature: CO concentration: 2 Light: Blue light is known to reduce respiration by influencing cyto b and cyto a / a 3 complex.
Moisture: Respiration is minimum in dry seeds where moisture content is 12-18%.
Mechanical stimulation and injury: Injury or infection increases the rate of respiration. Inorganic salts: Absorption of inorganic salts requires energy.
Respiratory substrate: Age: Respiration is high at the time of seed germination.
Inhibitors: Cyanides, CO, azides etc., inhibits respiration. Hormones:
Oxygen: The availability of Oxygen is directly proportional to the rate of aerobic respiration. State t of cell:
Practicals:
Q. Explain Ganong srespiroscope experiment with a neat labelled diagram.
Q. With a labelled diagram, describe the experiment to demonstrate the evolution of oxygen during photosynthesis in the presence of sunlight.
Q. Kuhne s fermentation flask experiment
B6 GROWTH AND GROWTH REGULATORS IN PLANTS (05 marks) 1 mark questions 2 marks questions
Q. Expand IBA Ans: Indole Butyric Acid
Q. Which is the commonly used selective weed killer? Ans: 2,4-D (2,4-dichlorophenoxy acetic acid)
Q. Name the hormone responsible for bolting in biennial plants. Ans: GA3. (Gibberellic acid)
Q. What is Richmond-Lang Ans: effect? Plants remain fresh and green for a long time under the influence of cytokinins. This is called Richmond-Lang effect.
Q. Expand ABA Ans: Abscissic acid
Q. Name the synthetic ethylene- releasing compound used as a fruit ripener. Ans: Ethylene
Q. Fruit flies swarm around ripe banana. Why? Ans: Ethylene
Give reasons (One mark each): Q. Removal of apical buds in some plants makes them grow bushy. Ans: It overcomes apical dominance
Q. Fruits of some plants are naturally seedless Ans: Excessive production of auxins
Q. Cytokinins are very essential for tissue culture Ans: They influence morphogenesis / differentiation
Q. ABA is known as dormin Ans: It induces dormancy
(2 marks each) Q. Define growth. Mention the phases of growth curve
Q. Write any two applications of synthetic auxins
Q. Write any four physiological roles of gibberellins
Q. Write any four physiological role of cytokinin in plants
Q. Mention two physiological functions of abscissic acid
Q. Give an example for gaseous phytohormone. Mention any two of its effects on plants