Mitotic Index Trend in Onion Root

Steps:

• Examine graph: Mitotic index decreases with increasing distance from root tip.
• Interpret trend: Higher mitotic index near tip indicates more active cell division there.
• Compare options to trend: Identify which aligns with decreasing division rate away from tip.
• Select best match: Option reflecting concentration of division near tip.

Why C is correct:

• Mitotic index formula shows proportion of dividing cells; decreasing values mean most mitosis occurs closer to tip where index is highest.

Why the others are wrong:

• A: Graph trend implies some division beyond 1 mm, though reduced.
• B: Similar to A; division likely persists beyond 1.4 mm at low levels.
• D: Not enough information; requires specific mitotic index value at 0.2 mm to verify 3% rate.

Final answer: C