Question

Place these mitotic events in the order that they occur, beginning with the earliest event at the top:

Nucleus envelope re-firms
Nuclear envelope breaks up and spindle fibers attach to chromosomes
Chromosomes align along the equator of the cell
Chromosomes condense and become visible
Sister chromatids separate

Answer 1

The correct order of events in mitosis is: nuclear envelope breaks up and spindle fibers attach to chromosomes, chromosomes condense and become visible, chromosomes align along the equator of the cell, sister chromatids separate, nucleus envelope re-forms.

Step-by-step explanation:

The correct order of events in mitosis is as follows:

1. Nuclear envelope breaks up and spindle fibers attach to chromosomes: During prophase, the nuclear envelope begins to dissociate into small vesicles and the microtubules form the basis of the mitotic spindle, attaching to the chromosomes.
2. Chromosomes condense and become visible: As prophase progresses, the sister chromatids begin to coil more tightly and become visible under a light microscope.
3. Chromosomes align along the equator of the cell: During metaphase, the chromosomes line up along the equator of the cell, forming the metaphase plate.
4. Sister chromatids separate: In anaphase, the sister chromatids separate and move towards opposite poles of the cell.
5. Nucleus envelope re-forms: During telophase, the nuclear envelope reforms around the separated sister chromatids.