The diagram given below represents a stage during cell division. Study the same and answer the questions that follow: The diagram given below represents a stage during cell division. Study the same and answer the questions that follow:
Draw a neat, labelled diagram of the stage mentioned in (iv).
Topic: Prophase — diagram
Answer
Draw PROPHASE. Since part (i) identified this as a PLANT cell, your diagram must show: • a rectangular CELL WALL (no centrioles and no aster) • CHROMOSOMES condensed and visible, each as two CHROMATIDS joined at a CENTROMERE, scattered within the nuclear area • the NUCLEAR MEMBRANE DISINTEGRATING, drawn as a broken line • the NUCLEOLUS disappearing • SPINDLE FIBRES beginning to form
Labels required: cell wall, chromosome, chromatid, centromere, nuclear membrane disappearing, spindle fibre.
WHAT IDENTIFIES PROPHASE, and what the examiner looks for: the chromosomes are visible but NOT yet lined up at the equator, and the NUCLEAR MEMBRANE is BREAKING DOWN. Draw that membrane as a dashed or broken line — it is the clearest way to signal the stage.
YOUR DIAGRAM MUST MATCH YOUR ANSWER TO PART (i). Having identified a plant cell, draw a plant cell — with a cell wall and without centrioles or asters. Drawing an animal cell here contradicts your own earlier answer, and examiners notice.
Each chromosome must be drawn DOUBLE (two chromatids joined at the centromere), since replication happened in interphase, before prophase began.