Applied Biology, Agriculture and Biotechnology
Applied biology, agriculture and biotechnology applies biological principles to food production and industry. Questions test nutrient management, propagation, pest control and fermentation.
Soil and plant nutrition
Soil texture, pH and organic matter affect root growth and nutrient availability. Nitrogen supports leaf growth, phosphorus root development and potassium fruit quality. Fertiliser recommendations are given as kg of nutrient per hectare, but products are sold by mass, so convert using the percentage composition.
Crop and animal production
Irrigation scheduling, mulching and crop rotation conserve water and reduce pests. Integrated pest management combines resistant varieties, biological control and limited pesticide use. Animal husbandry requires balanced feed, clean water, vaccination and hygiene.
Biotechnology
Tissue culture produces disease-free clones from meristem tissue under sterile conditions. Genetic engineering inserts genes using vectors and restriction enzymes. Fermentation uses microorganisms to make products such as curd, vinegar and ethanol; temperature, pH and sterility must be controlled.
Worked example
A recommendation is 60 kg N per hectare. Urea is 46% N by mass. Mass of urea = 60/0.46 = 130.4 kg per hectare. Applying 130 kg rather than 60 kg avoids a serious under-dose.
Traps
Confusing elemental nutrient mass with fertiliser product mass, treating N-P-K figures as percentages of compounds rather than of the elements, and ignoring contamination in tissue culture.