Chromosome Contraction During Cell Cycle

Chromosomes go through various changes in structure and size throughout the cell cycle. Let's explore when chromosomes are shortest and thickest.

Anaphase
- During anaphase, chromosomes are at their shortest and thickest.
- This is the stage when sister chromatids are pulled apart towards opposite poles of the cell by the spindle fibers.
- As the chromatids are separated, they become condensed and appear shorter and thicker.

Metaphase
- In metaphase, chromosomes are aligned along the equatorial plate of the cell.
- They are condensed and visible under a microscope, but not as short and thick as during anaphase.
- Metaphase is a crucial stage where chromosomes are ready to be pulled apart during anaphase.

Telophase
- Telophase is the stage where chromosomes begin to de-condense and return to their less condensed state.
- Chromosomes start to elongate and become less visible as distinct structures.
- They are not as short and thick as in anaphase during this stage.

Interphase
- Interphase is the stage between cell divisions when chromosomes are in their least condensed form.
- Chromosomes are dispersed throughout the nucleus and are not visible under a light microscope.
- This is the phase where chromosomes replicate and prepare for the next cell division.

In conclusion, chromosomes are shortest and thickest during anaphase, when they are actively being separated and moved to opposite poles of the cell. During metaphase, they are aligned at the center of the cell, while in telophase, they begin to de-condense. In interphase, chromosomes are in their least condensed state as they prepare for the next cell division.