Govt Exams
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.
Photosynthesis is the primary source of energy for plant cells as it converts light energy into chemical energy in the form of glucose.
Root hairs are unicellular extensions of root epidermis that greatly increase absorptive surface area for water and mineral uptake.