Introduction / Context:
Understanding how plants obtain their essential requirements is a fundamental topic in biology. While students often know that plants need sunlight, water, air and nutrients, it is important to distinguish which component provides energy and which supplies mineral nutrients. Competitive exams frequently test whether candidates can identify that soil is the primary source of mineral nutrients absorbed by plant roots for healthy growth and development.
Given Data / Assumptions:
• The question asks where plants mainly receive their nutrients from.
• Options include sunlight, soil, pesticides and chlorophyll.
• ‘‘Nutrients’’ here refers mainly to mineral nutrients like nitrogen, phosphorus and potassium.
Concept / Approach:
Plants use different sources for different needs. Sunlight provides energy for photosynthesis, carbon dioxide comes from air, and water and mineral nutrients are primarily absorbed from the soil through roots. Essential nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium and trace elements are dissolved in soil water and taken up by the root system. Therefore, when asked where plants ‘‘mainly receive their nutrients’’, the accurate answer is soil, not sunlight or chlorophyll.
Step-by-Step Solution:
1. Recall that plants require water, mineral nutrients, carbon dioxide and sunlight.
2. Energy for photosynthesis comes from sunlight, but it is not a nutrient itself.
3. Mineral nutrients are absorbed by roots from the soil solution.
4. Pesticides are chemicals applied to control pests and are not nutrient sources.
5. Chlorophyll is a green pigment inside leaves that captures light; it does not supply nutrients.
6. Therefore, the main source of nutrients for plants is the soil.
Verification / Alternative check:
Textbooks on plant physiology clearly state that roots absorb water and dissolved minerals from the soil. Agricultural practices like fertilization, manuring and soil testing all revolve around improving the nutrient content of soil to promote plant growth. This practical evidence from farming and gardening further confirms that soil is the primary nutrient source for plants.
Why Other Options Are Wrong:
Option A, sunlight, is essential for photosynthesis but does not provide mineral ions such as nitrate or phosphate. Option C, pesticides, are applied to kill or repel pests and diseases; excessive use can even harm plants and soil organisms. Option D, chlorophyll, is part of the plant's internal structure and enables light absorption; it is not an external nutrient source. Thus, these alternatives misunderstand the role of energy, chemicals and pigments in plant life.
Common Pitfalls:
Students sometimes equate ‘‘needs’’ with ‘‘nutrients’’ and assume that since sunlight is crucial, it must also be the main nutrient source. Another pitfall is to confuse fertilizers and pesticides, thinking both supply useful substances to plants. Remember that nutrients refer to chemical elements like nitrogen and potassium, and these mainly come from the soil solution that roots absorb.
Final Answer:
Plants mainly receive their mineral nutrients from the
soil.
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