Generation of heat within the storage container.
Explanation
Seeds, even when stored and seemingly dormant, are living entities that perform basal metabolic activities to maintain viability. The most fundamental of these activities is cellular respiration, a catabolic process where stored food reserves are broken down in the presence of oxygen to release energy.
Detailed Analysis
- Respiration as an Exothermic Process: Cellular respiration involves the oxidation of respiratory substrates (such as carbohydrates, fats, or proteins). This biochemical reaction releases energy, a portion of which is stored as ATP (Adenosine Triphosphate), while the rest is dissipated as heat.
- Heat Accumulation in Storage: When seeds are stored in bulk (e.g., in gunny bags or silos), the heat generated by the respiration of individual seeds accumulates because the insulating properties of the grain mass prevent rapid dissipation. This results in a perceptible rise in temperature within the storage container.
- Comparison with Other Options:
- Absorption of moisture : This is primarily a physical process known as imbibition or hygroscopy, dependent on the humidity gradient, not necessarily a sign of metabolic respiration.
- Change in colour and Volume reduction : These are not direct or immediate indicators of respiration. While dry weight decreases during respiration, volume changes are influenced by moisture content and physical packing.
Key Takeaway:
Cellular respiration is an exothermic process. The generation and accumulation of heat in stored seeds provide physical evidence that metabolic breakdown of substrates is occurring.