Question

Опишите втарую стадию деления клетки

Answer 1

Правильный ответ: метафаза

Answer 2

Вторая стадия деления клетки называется метафаза. В этой стадии хромосомы, состоящие из двух хроматид, выстраиваются на экваторе клетки. К центромерам каждой хромосомы прикреплены по две нити веретена деления, которые исходят от центриолей, расположенных у полюсов клетки. Метафаза является самой длительной стадией митоза, так как в ней происходит точное выравнивание хромосом, что обеспечивает их равномерное распределение между дочерними клетками. Вы можете увидеть схематическое изображение метафазы на [этом сайте](https://scienceland.info/biology10/mitosis).

Answer 3

The Process of Cell Division

Cell division is the process by which a parent cell divides into two or more daughter cells. It is a fundamental process in all living organisms and is essential for growth, development, and the maintenance of tissues. There are two main stages of cell division: the interphase and the mitotic phase.

Interphase

Interphase is the first stage of the cell division process. It is a period of growth and preparation for cell division. During interphase, the cell undergoes several important processes:

1. G1 Phase: The cell grows and carries out its normal functions. It synthesizes proteins, RNA, and other molecules necessary for cell growth and division.

2. S Phase: DNA replication occurs during this phase. The cell's DNA is duplicated, resulting in two identical copies of each chromosome. This ensures that each daughter cell will receive a complete set of genetic information.

3. G2 Phase: The cell continues to grow and prepares for cell division. It synthesizes additional proteins and organelles needed for the upcoming division.

Mitotic Phase

The mitotic phase is the second stage of cell division, during which the cell divides into two daughter cells. It consists of several distinct steps:

1. Prophase: The chromatin, which is the loosely packed form of DNA, condenses into visible chromosomes. The nuclear envelope breaks down, and the mitotic spindle, composed of microtubules, begins to form.

2. Prometaphase: The nuclear envelope completely disintegrates, and the mitotic spindle attaches to the chromosomes. Each chromosome becomes connected to the spindle fibers at a specialized region called the kinetochore.

3. Metaphase: The chromosomes align along the equatorial plane of the cell, known as the metaphase plate. This alignment ensures that each daughter cell will receive an equal number of chromosomes.

4. Anaphase: The sister chromatids, which are the duplicated copies of each chromosome, separate and move towards opposite poles of the cell. This movement is facilitated by the shortening of the microtubules of the mitotic spindle.

5. Telophase: The separated chromosomes reach the opposite poles of the cell. The nuclear envelope reforms around each set of chromosomes, and the chromosomes begin to decondense. The mitotic spindle disassembles.

6. Cytokinesis: Cytokinesis is the final step of cell division. It involves the division of the cytoplasm and the formation of two separate daughter cells. In animal cells, a cleavage furrow forms and gradually deepens, eventually separating the two cells. In plant cells, a cell plate forms in the middle of the cell and develops into a new cell wall, dividing the cell into two.

Conclusion

The process of cell division involves two main stages: interphase and the mitotic phase. During interphase, the cell grows and prepares for division, while the mitotic phase includes prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Each stage is crucial for the proper division of genetic material and the formation of two daughter cells.