1. Transport in Plants

Plants absorb water and minerals from the soil through roots and transport them to various parts via xylem. Similarly, photosynthates produced during photosynthesis are transported from source tissues (usually leaves) to sink tissues (e.g., roots, fruits) through phloem. Transport in plants occurs through both short-distance processes like diffusion and osmosis, and long-distance processes like transpiration pull for water transport and translocation for sugar transport.

2. Mineral Nutrition

Plants require essential mineral nutrients absorbed from the soil for their growth and development. These are broadly categorized as macronutrients (required in large amounts, e.g., Nitrogen, Phosphorus, Potassium) and micronutrients (required in trace amounts, e.g., Iron, Zinc, Copper). Deficiencies in these minerals can lead to stunted growth, chlorosis (yellowing of leaves), and reduced yield, impacting agriculture significantly in regions like India.

3. Photosynthesis in Higher Plants

Photosynthesis is the process by which green plants use sunlight, water, and carbon dioxide to synthesize organic food molecules (glucose) and release oxygen. This vital process occurs in chloroplasts, primarily in leaves. It involves two main stages: the light-dependent reactions (capturing light energy) and the light-independent reactions or Calvin cycle (using this energy to fix carbon dioxide). Photosynthesis forms the base of most food chains on Earth.

4. Respiration in Plants

Plant respiration is the process by which plants break down organic molecules (like glucose) to release energy, which is then used for various metabolic activities. This process occurs in all living cells of the plant, day and night, and involves stages like glycolysis, Krebs cycle, and oxidative phosphorylation, consuming oxygen and releasing carbon dioxide and water. Respiration is essential for plant growth, maintenance, and reproduction.

5. Plant Growth and Development

Plant growth is an irreversible increase in size or mass, while development encompasses all changes an organism undergoes throughout its life, from germination to senescence. Growth occurs through cell division, enlargement, and differentiation. Plant hormones, such as auxins, gibberellins, cytokinins, abscisic acid, and ethylene, play crucial roles in regulating these processes, influencing everything from root formation to flowering and fruit ripening.