Which term describes the structure formed due to elongation of the radicle?

• A. Lateral root
• B. Primary root
• C. Secondary root
• D. Adventitious root

Answer: (B)

The main idea here is that the first root formed during germination is produced when the radicle elongates. The radicle is the embryonic root, and as it grows it becomes the primary root—the main rooting axis of the young plant. Lateral or secondary roots are later branches that arise from this primary root, not the initial product of radicle elongation. Adventitious roots come from non-root tissues, such as stems or leaves, and are unrelated to the radicle’s elongation. So the structure produced directly by elongation of the radicle is the primary root.