Revision Notes of Plants Growth & Short tricks :-
🔭🔭 A single maize root apical meristem can be give rise to more than 17500 new cells per hour
💊💊 A wateremelon cell can increase its size upto 3,50,000 times
📪📪 Arithmetic growth rate – Only one daughter cell continuous to divide while others differentiate and matures
📣📣 Geometric growth rate – all the daughter cells produced will divide..Sigmoid growth curve is obtained
📌📌 Absolute growth rate – Increase in growth per unit time
📍📍 Relative growth rate – Increase in growth per unit time per unit initial parameter
🎡🎡 Relative growth rate also called as Efficiency index
🎢🎢 Differentiation – Conversion of meristamatic cell into structurally and functionally specialised Primary permanent tissue…eg: Formation of primary xylem
🎠🎠 Dedifferentiation – Conversion of primary permanent tissue to Secondary meristems….eg: Formation of cork cambium
🎪🎪 Redifferentiation – Formation of secondary permanent tissus from secondary meristems….eg: Formation of secondary xylem
🎥🎥 Development in plants = Growth + differentiation
🎭🎭 Eg of plasticity – Heterophylly in cotton, coriander, larkspur in which leaves of juvenile and mature stages are different……Heterophylly in buttercup in which leaves in terrestrial and aquatic habitat plants are different
molecule They can be indole compounds eg: Indole 3 acetic acid (IAA)…..Adenine derivatives eg: N6 furfuryl amino purine, kinetin…..carotenoids eg: abscisic acid….terpenes eg: gibberellic acid….Gases eg: ethylene
🐝🐝 Plant growth promotors – Auxin, Cytokinin, Giberellic acid
🐞🐞 Plant growth inhibitors – Abscisic acid
🐲🐲 Ethylene has both properties
💝💝 Auxin – Effects :
🎓1. First isolated from human urine
🎓2. IAA & IBA are natural auxins and NAA & 2,4 – D are synthetic auxins
🎓3. Auxin initiate roots in stem cuttings
🎓4. It promotes flowering in pineapples
🎓5. Prevent abscission of young fruit and leaf…promotes abscission of old leaf & fruits
🎓6. Promote apical dominance 7. 2,4-D act as herbicide in dicots
💝💝 Gibberellins – Effects
🌈🌈1. Increase length of grape stalks
🌈🌈2. Causes fruits like apple to elongate and improve its shape
🌈🌈3. Delay senescence
🌈🌈4. GA3 promote malting in brewing industry
🌈🌈5. Increase length of stem in sugarcane and increase yield upto 20 tonnes per acre
🌈🌈6. Cause internodal elongation in beet, cabbage, and other rosette plants
💝💝 Cytokinins – Effects
⛳️⛳️1. Promote cell division
⛳️⛳️2. Overcome apical dominance
⛳️⛳️3. Promote nutrient mobilisation
💝💝 Ethylene – Effects
🚀🚀1. Promotes senescence and abscission
🚀🚀2. Promote ripening
🚀🚀3. Breaks seed and bud dormancy
🚀🚀4. Helps leaf & upper part of shoot to remain above water
🚀🚀5. Initiate flowering in pineapple
💝💝 Abscissic acid – Effects
🚔🚔1. Inhibits seed germination
🚓🚓2. Also called stress hormone
🐍🐍3. Antagonist to
IMP OF ENVIRONMENTAL ISSUES
🍀Environment (Protection) Act
>Passed by Government of India in 1986
>To protect and improve the quality of the environment
🍀Air (Prevention and Control of Pollution) Act
>Passed in 1981
>Amended in 1986 to include noise under air pollution
🍀Water (Prevention and Control of Pollution) Act
>Passed in 1974 to protect water bodies
🍀Montreal Protocol
>Signed in 1987 and came into effect from 1989
>To protect the ozone layer by controlling the use of ozone-depleting substances such as CFCs
🍀Joint Forest Management (JFM)
>Conceptualised in 1980 by Government of India
>It involves a joint partnership of local communities and forest department in the protection and management of forests
🍀Chipko Movement
>In 1974, Garhwal Himalayas
🍀National Forest Policy
>Came into force in 1988
>According to it, plains should have 33% forest cover and hills 67% forest cover
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