Govt Exams
Rhizobium bacteria in root nodules of legumes fix atmospheric nitrogen into ammonia through nitrogenase enzyme.
Cohesion-tension theory explains that water is pulled upward due to transpirational pull creating negative pressure in xylem.
CAM plants like pineapple, cactus, and agave fix CO2 at night into organic acids and release during day for photosynthesis.
RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyzes CO2 fixation with RuBP in the Calvin cycle.
Water photolysis (2H2O → O2 + 4H+ + 4e-) releases electrons that are transferred through electron transport chains.
Transpiration is the loss of water vapour from aerial parts of plants, primarily through stomata during daytime.
Sieve tube members conduct sugars while companion cells provide ATP and metabolic support for active transport.
Osmotic potential (Ψs) = -iCRT, where it depends on solute concentration (C) and absolute temperature (T).
High auxin to low cytokinin ratio promotes callus formation, while the ratios determine the type of organogenesis.
Abscisic acid (ABA) accumulates during water stress and environmental changes, promoting abscission layer formation and leaf fall.