GED Science TestLife ScienceMedium
A farmer observes that a particular variety of corn planted in a specific field consistently yields crops with stunted growth and yellowing leaves, despite adequate watering and sunlight. A soil test reveals a severe deficiency in a nutrient crucial for chlorophyll formation and overall plant vigor. Which of the following nutrients is most likely deficient?
- ACalcium
- BPhosphorus
- CNitrogen
- DPotassium
Show answer & explanationAnswer & explanation
Correct answer: C. Nitrogen
Nitrogen is a key component of chlorophyll, amino acids, and nucleic acids. A deficiency in nitrogen commonly leads to stunted growth and chlorosis (yellowing of leaves), particularly older leaves, as the plant reallocates nitrogen to new growth.
Why the other options are wrong
- A. Calcium deficiency typically affects new growth, causing distorted leaves and stunted roots.
- B. Phosphorus deficiency leads to dark green or purplish leaves, stunted growth, and poor root development.
- D. Potassium deficiency often results in yellowing or browning of leaf margins and reduced fruit/flower development.
Nitrogen in Plants
A macronutrient essential for plant growth, crucial for the formation of chlorophyll (for photosynthesis), amino acids (for proteins), and nucleic acids (DNA/RNA).
- Deficiency causes chlorosis (yellowing) and stunted growth.
- Abundant in healthy soil and fertilizers.
- Absorbed as nitrate (NO3-) or ammonium (NH4+).
Memory trick: N-P-K: Grow, Flower, Root.