Question

1. sketch a picture of a cell going through each phase in meiosis. next to each picture, briefly highlight any key events during the stage.

Explanation:

To solve this, we analyze the stages of meiosis (Meiosis I and Meiosis II) and their key events:

Meiosis I

• Prophase I: Chromosomes condense, homologous chromosomes pair (synapsis), crossing over occurs (exchange of genetic material between non - sister chromatids). The nuclear envelope breaks down, and the spindle apparatus forms.
• Metaphase I: Homologous chromosome pairs (tetrads) align at the cell’s equatorial plate (metaphase plate). Spindle fibers attach to the centromeres of each homologous chromosome.
• Anaphase I: Spindle fibers pull homologous chromosomes apart to opposite poles of the cell. Sister chromatids remain attached at their centromeres.
• Telophase I & Cytokinesis: Chromosomes reach the poles. The nuclear envelope may reform (in some cells). The cell divides into two daughter cells (cytokinesis), each with half the number of chromosomes (but still with sister chromatids).

Meiosis II

• Prophase II: If the nuclear envelope reformed in Telophase I, it breaks down again. Chromosomes condense, and the spindle apparatus forms in each of the two daughter cells.
• Metaphase II: Chromosomes (each with two sister chromatids) align at the metaphase plate of each daughter cell. Spindle fibers attach to the centromeres of sister chromatids.
• Anaphase II: Sister chromatids are pulled apart to opposite poles of each daughter cell (now called chromosomes).
• Telophase II & Cytokinesis: Chromosomes reach the poles. The nuclear envelope reforms, and cytokinesis occurs, resulting in four haploid daughter cells (gametes in animals, spores in plants/fungi).

For the sketches:

• Draw a cell (oval or rectangular) for each stage.
• In Prophase I, show paired homologous chromosomes (with crossing over, e.g., “X” shapes overlapping).
• In Metaphase I, show tetrads lined up at the center.
• In Anaphase I, show homologous chromosomes moving to opposite ends.
• In Telophase I/Cytokinesis, show two smaller cells.
• Repeat for Meiosis II stages, showing the events (e.g., in Anaphase II, sister chromatids separating).

Answer:

To complete the task, sketch the cell in each meiosis stage (Prophase I, Metaphase I, Anaphase I, Telophase I/Cytokinesis, Prophase II, Metaphase II, Anaphase II, Telophase II/Cytokinesis) and label key events as explained (synapsis/crossing over in Prophase I, tetrad alignment in Metaphase I, homologous separation in Anaphase I, cell division in Telophase I/Cytokinesis; and corresponding events in Meiosis II like sister chromatid separation in Anaphase II).