Govt. Exams
Entrance Exams
Soil pH has minimal direct effect on transpiration rate. Primary factors affecting transpiration are light, humidity, temperature, and wind velocity.
Chlorophyll a is the primary pigment that directly participates in the photochemical reactions of both PSI and PSII, while other pigments act as accessory pigments.
The source in phloem transport is any photosynthetically active tissue, primarily mature leaves, which produce and load photosynthates into sieve tubes.
Abscisic acid is the stress hormone that promotes stomatal closure during drought by reducing guard cell turgor pressure, thereby reducing water loss.
Magnesium is the central atom in the porphyrin ring of chlorophyll molecules, making it essential for photosynthetic light absorption.
The Calvin cycle (light-independent reactions) takes place in the stroma of chloroplasts, where CO2 is fixed and glucose is synthesized.
Diffusion is a passive process that does not require ATP; substances move along the concentration gradient.
Phototropism is the directional growth response of plants towards light, mediated by differential distribution of auxin.
Auxin promotes cell elongation and causes apical dominance by inhibiting lateral bud growth through differential distribution.
Dark reactions (Calvin cycle) do not directly require light; they use ATP and NADPH produced from light reactions to fix CO2.
