Railway Science (Biology-Nutrition in Plant)

Glucose (C₆H₁₂O₆ ), a type of carbohydrate, made by the process of photosynthesis may be used in three ways : It can be converted into chemicals required for growth of plant cells such as cellulose, converted into starch that can be converted back to glucose when the plant requires it, It can be broken down during the process of respiration releasing energy stored in the glucose molecules.

Food, amino acids and hormones (related to Active transport). Depending on the expenditure of energy, there are majorly two types of transport across membranes, Active transport and Passive transport.
Passive transport - This does not require any energy expenditure as it occurs along the concentration gradient of the molecule being translocated. Examples include simple diffusion, facilitated diffusion, and osmosis.

Plant nutrition - An element which is essential or beneficial for plant growth and reproduction, plant metabolism and their external supply.
Minerals and nutrients are absorbed by water in plants, It uses the water in the soil at the root zone.
Main nutrients (NPK) - Nitrogen (N), phosphorus (P) and potassium (K). Other nutrients - calcium (Ca), magnesium (Mg) and sulphur (S). Micronutrients - Boron (B), Chlorine (Cl), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn).

Osmosis: Movement of water from a region of higher concentration to a region of lower concentration through a semipermeable membrane, helps in stabilizing the internal environment of the organism by balancing the levels of water and intracellular fluids.
Diffusion is the process of movement of molecules under a concentration gradient, which helps in the movement of substances in and out of the cells. Transpiration helps in the conduction of water and minerals to different parts of the plants.

Transpiration - Process of removing surplus water from the plant's body. Water molecules in the plant tissues are removed from the aerial parts of the plants.
Types of Transpiration : Stomatal Transpiration - The water on the surface of leaves changes into vapour and evaporates when the stomata are open. Lenticular Transpiration - Evaporation of water from the lenticels.
Cuticular Transpiration - Water from the leaves is lost through cuticular transpiration during dry conditions.

Photosynthesis - The process by which green plants produce carbohydrates by absorbing carbon dioxide, water and sunlight in the presence of chloroplasts and releasing chemical energy.
Equation - 6CO₂ (Carbon dioxide) + 6H₂O (Water) → C₆H₁₂O₆ (Glucose) + 6O₂ (Oxygen). Factors affecting photosynthesis - Carbon dioxide concentration, Water availability, Nutrient availability, Temperature, Sunlight and Chlorophyll (a green pigment found in the chloroplasts of cells).

Photosynthesis converts solar energy into chemical energy. Oxygen is released as a by-product. Synthesized food is stored as carbohydrates (glucose as well as starch). Chlorophyll (a green pigment) found in the chloroplasts (sites of photosynthesis - found only in plant cells).

Functions - Promotes cell division and increases cell expansion. Other types of Plant Hormones and their functions : Gibberellin - Controls germination, elongation growth, flower development.
Auxins - Embryonic development, root and stem tropisms, apical dominance and transition to flowering. Abscisic acid - Regulating plant growth, development, and stress responses.

Saprotrophic nutrition: Mode of nutrition in which organisms obtain their food from the dead and decaying organic matter of plants and animals. Examples of saprotrophic organisms - Mushrooms, Rhizopus (bread mould), Mucor (pin mould), Yeast.
Chemotrophic nutrition - Organisms synthesize many organic compounds using inorganic compounds with carbon atoms. Example - Bacteria.
Symbiotic nutrition - Mutual sharing of shelter and nourishment by two different organisms. Example - leguminous plant and Rhizobium bacteria.