16.1.6—Meiosis image interpretation

Interpret a meiosis photomicrograph or diagram by matching visible chromosome behaviour to the division and stage. Use pairing, alignment, centromere behaviour and cell number together rather than relying on one shape or position.

1. Decide whether meiosis I or meiosis II is shown. Homologous chromosomes paired side by side indicate meiosis I; single chromosomes suggest meiosis II. Two forming cells support meiosis I, while four forming haploid cells support meiosis II.
2. Identify the PMAT evidence: condensed chromosomes in prophase; chromosomes aligned at the spindle equator in metaphase; chromosomes or chromatids moving to opposite poles in anaphase; nuclei reforming and cytokinesis beginning in telophase.
3. Check the separation event. In anaphase I, whole homologous chromosomes move while centromeres remain intact. In anaphase II, centromeres divide and sister chromatids move apart.
4. Cross-check spindle direction, nuclear-envelope change and cell-surface division, then state the stage only when multiple visible clues agree.

A crowded, rotated or unevenly stained image may hide a clue. Record only visible evidence, explain how the evidence supports the stage label, and avoid inventing chromosome details that the image does not show.

A pair of dark shapes is not automatically a homologous pair, and anaphase I is not the same as anaphase II. This card is an image/diagram interpretation method; it does not add a separate mechanism for genetic variation.