Ijmb Model Questions Vol1 2022 Biology Question 2

Practice practical question 2 from the 2022 Ijmb Model Questions Vol1 Biology examination. This question covers Cell Division .

Ijmb Model Questions Vol1 2022 Biology Practical

Topic: Cell Division

Question 2 IJMB_MODEL_QUESTIONS_VOL1 • 2022 • BIOLOGY • practical

You are to examine a prepared slide of an onion (Allium cepa) root tip that has been stained with aceto‑orcein to reveal chromosomes during mitosis. Use the same microscope (10× ocular, 40× objective).

Question Parts

( a )

Describe how you locate the region of the root tip where mitotic figures are most abundant. State the characteristic features you use to identify this meristematic zone.

( b )

From a single field of view, count 200 cells and record how many are in each stage of mitosis: prophase, metaphase, anaphase, telophase, and interphase. The observed numbers are: prophase 30, metaphase 50, anaphase 40, telophase 20, interphase 60. Verify that the total count is correct.

( c )

Calculate the mitotic index (MI) using the formula MI = (Number of cells in mitosis / Total cells observed) × 100. Show your working.

( d )

Interpret the mitotic index obtained. What does a high or low mitotic index indicate about the growth activity of the root tip?

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About This Question

This is Ijmb Model Questions Vol1 2022 Biology Question 2. It is one of the practical questions from the 2022 Ijmb Model Questions Vol1 Biology examination.

The question covers Cell Division .

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