Nitrate Deficiency Causes Stunted Growth in Young Leaves

Steps:

• Nitrate is a key nitrogen source for amino acid and protein synthesis in plants.
• Deficiency limits protein production, impairing cell division and expansion.
• Nitrogen is mobile, so older leaves sacrifice nutrients to support young leaves, but overall growth slows.
• Symptoms include reduced leaf size and slow development in new growth areas.

Why D is correct:

• Nitrate enables chlorophyll and protein formation; lack thereof directly stunts young leaf growth via halted meristem activity.

Why the others are wrong:

• A: Dark green leaves indicate excess nitrogen, not deficiency.
• B: Deficiency causes yellowing from chlorophyll loss, not color gain.
• C: Yellowing (chlorosis) affects older leaves in nitrate deficiency, not the primary effect on young leaves.

Final answer: D