Which phase of the cell cycle is best to determine chromosom

Which phase of the cell cycle is best to determine chromosome appearance and number in a cell?

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Solution

Hi,

The answer is : G2.

The chromosomes do not always appear as the ones we look in pictures. When the cell is not growing, the chromosomes exists as fine threads spread in nucleus. Only when the cell prepares to divide , the chromosomes start to coil tightly and form into structures what we see in usual chormosome images. The homologous chromosomes align together and cell divides. The cell division is divided into 4 stages,

1. G0 = resting phase. The chromosomes are loosly coild, no apparent 3D structure.

2. g1 = Prophase- cell prepares to divide, active protein synthesis.

3. S = DNA replication, chromosomes start to condense.

4. G2= chromosome condensation is complete. cell is ready to divide by either mitosis or meiosis.

Hence the answer is G2.