Final answer:
Wilting in plants is primarily caused by water deficiency, while stunted growth can occur due to a lack of essential nutrients such as nitrogen and calcium. Undernutrition in children also leads to stunting, with potential irreversible effects on development.
Step-by-step explanation:
The nutrient that causes wilting and stunted growth in plants is typically water. Water is critical for maintaining the structural integrity of plant cells and the overall plant structure. When a plant experiences water deficiency, it will wilt because the cells lose turgor pressure, which is the pressure of the cell contents against the cell wall. Without adequate water, cells cannot maintain this pressure, and the plant begins to droop. Additionally, the metabolism of a plant is compromised without sufficient water, as water is essential for metabolic processes.
On the other hand, stunted growth in plants is often linked to a deficiency in essential nutrients such as nitrogen, calcium, potassium, magnesium, and others. A shortage of these nutrients can lead to various growth problems, including slower growth rates, yellowing leaves (chlorosis), and less robust overall plant health. In severe cases, such deficiencies can also cause cell death in the leaves.
Undernutrition in children also leads to stunted growth, not just because of water deficiency, but due to a lack of calories and essential micronutrients like iron, vitamin A, and iodine. These deficiencies can result in a host of developmental issues and diseases, emphasizing the need for adequate nutrition for both plants and humans.