Analyze how environmental factors such as light and gravity influenceplant growth and development. How do plants adapt when these factors arealtered?
Answer (1)
1. Plant Growth and Development:Growth = Increase in height, root length, number of leaves, etc.Development = Formation of specific structures and life stages (seedling, flowering, fruiting).Controlled by plant hormones like auxins, gibberellins, cytokinins, ethylene, and abscisic acid.2. Adaptation to Changing Factors:Plants cannot move, so they adapt physically and chemically to survive when factors change:a) Light:In low light, they grow tall and pale (etiolation) to reach light.In high light, they develop thicker leaves or protective pigments.b) Water:In dry areas, plants reduce leaf size, grow deep roots, or store water in stems (e.g., cactus).In wet areas, plants develop air spaces in roots (aerenchyma) to help with breathing.c) Temperature:In cold, some enter dormancy or produce antifreeze proteins.In heat, they open stomata for cooling or develop reflective leaf surfaces.d) Nutrients:In poor soils, plants may grow more roots or form symbiotic relationships (e.g., legumes with nitrogen-fixing bacteria).
