Question

Как происходит деление клетки при митозе​

Answer 1

Ответ:

В процессе митоза происходит распределение ДНК хромосом материнской клетки строго поровну между возникающими из неё двумя дочерними клетками. Два последовательно сменяющих друг друга деления. Между двумя делениями – короткая интерфаза, во время которой не происходит удвоения ДНК.

Answer 2

Ответ:

Митоз — процесс непрямого деления соматических клеток эукариот, в результате которого из одной диплоидной материнской клетки образуются две дочерние с таким же набором хромосом. Подготовка клетки к митозу происходит в интерфазу: удваивается ДНК, накапливается АТФ, синтезируются белки веретена деления, удваиваются центриоли.

Answer 3

Mitosis: Cell Division in Detail

Mitosis is the process by which a cell divides to produce two identical daughter cells. It is a crucial process for growth, repair, and maintenance of multicellular organisms. Let's dive into the details of how mitosis occurs.

Phases of Mitosis

Mitosis consists of several distinct phases, each with its own characteristics and events. These phases are:

1. Interphase: This is the phase before mitosis begins. During interphase, the cell grows, carries out its normal functions, and replicates its DNA. Interphase is further divided into three subphases: G1, S, and G2.

- G1 phase: The cell grows and carries out its normal functions. - S phase: DNA replication occurs, resulting in the duplication of the cell's genetic material. - G2 phase: The cell continues to grow and prepares for mitosis.

2. Prophase: This is the first phase of mitosis. During prophase, the chromatin (loosely packed DNA) condenses into visible chromosomes. The nuclear membrane breaks down, and the mitotic spindle begins to form.

3. Prometaphase: In this phase, the nuclear membrane completely dissolves, and the chromosomes become more condensed. The mitotic spindle attaches to the centromeres of the chromosomes.

4. Metaphase: During metaphase, the chromosomes align along the equatorial plane of the cell, known as the metaphase plate. This alignment ensures that each daughter cell receives an equal number of chromosomes.

5. Anaphase: Anaphase is characterized by the separation of sister chromatids. The mitotic spindle pulls the sister chromatids apart, moving them towards opposite poles of the cell.

6. Telophase: Telophase marks the final stage of mitosis. The chromosomes reach the opposite poles of the cell, and a new nuclear membrane forms around each set of chromosomes. The chromosomes begin to decondense, and the mitotic spindle disassembles.

7. Cytokinesis: Cytokinesis is the division of the cytoplasm, which occurs after mitosis. In animal cells, a cleavage furrow forms, pinching the cell in two. In plant cells, a cell plate forms, eventually dividing the cell into two daughter cells.

Regulation of Mitosis

The process of mitosis is tightly regulated to ensure accurate cell division. Several checkpoints exist throughout the cell cycle to monitor DNA integrity and ensure that each phase is completed correctly before proceeding to the next. These checkpoints help prevent the formation of abnormal cells and the development of diseases like cancer.

Conclusion

Mitosis is a highly regulated process that allows cells to divide and produce identical daughter cells. It involves several distinct phases, including interphase, prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Each phase has specific characteristics and events that contribute to the accurate division of genetic material. The regulation of mitosis through checkpoints ensures the integrity of DNA and the proper progression of the cell cycle.