Question

During which stages of the cell cycle does a chromosome consist of two identical chromatids?

Short answer

Duplication of chromosomes is an important event of the cell cycle; This leads to the formation of one more copy of the chromosomes. In the S phase of the cell cycle, the chromosome bear two exact same chromatids.

This remains till the end of the metaphase of the cell cycle. In metaphase, the duplicated chromatids are placed in the mid of the cell-cell interaction at the equatorial plate, and these get separated in anaphase.

Step-by-step solution

Cell cycle

The cell cycle is formed of two vital events; these are the Interphase and the M phase. The Interphase is a very long phase, and the M phase is a short phase.

The different parts of the cell cycle are the G1 phase, S phase, G2 phase, M phase, and G0 phase. Amino acids, ATP synthesis, and the synthesis of enzymes are observed in the G1 phase of the cell cycle.

S phase of cell cycle

The S phase is otherwise called the synthesis phase. DNA content in this phase becomes twice, but the number of chromosomes does not increase. In this phase, the duplication of centrioles also occurs, and synthesis of histone also takes place.

M phase of cell cycle

The M phases are divided into two phases, karyokinesis and cytokinesis. The cell division occurs by two methods that are meiosis and mitosis. Mitotic division occurs in somatic cells that produce the same daughter cells with the same amount of DNA as that of the parental cell.

Prophase is the initial phase, next is the metaphase phase, anaphase is the third phase, and the last one is telophase. From the S phase to the metaphase, chromatids remain in duplicate form.