How Do Cells Divide - Phases Of Mitosis - Cell Division And The Cell Cycle - Cellular Division

In this video we discuss how do cells divide and what is the cell cycle. We cover the different phases of cell division, and what takes place during each of these phases.
Transcript/notes

Cell division

There are 2 types of cell division in the body, mitosis and meiosis. Meiosis occurs in the sex cells, egg cells in females, and sperm cells in men. And mitosis the type of cell division that occurs in all other cells in the body. In this video we are going to cover mitosis.

Cell division occurs when a parent cell divides to produce 2 daughter cells. Cell division is important in tissue growth, tissue repair caused by some sort of trauma or disease, and replacement of dying or old cells.

The cell-division cycle has 2 major phases, interphase and the mitotic phase. We will use the chart on the screen to go through this process.

During interphase the cell prepares for division, there are 3 sections in interphase; G1 phase, S phase and G2 phase.

During the G1 phase, cells produce new organelles, increase the supply of proteins and the centrioles begin replicating to eventually produce 2 new pairs.

During the S phase, DNA replication takes place. The DNA strands are unwound by DNA polymerase enzymes, free deoxyribonucleotides are paired up with the open DNA strands and the strands are returned to their coiled helix structure.

During the G2 phase, the centriole replication is completed and the cell continues to grow and prepare for division.

Once the interphase is complete, the M phase or mitotic phase will begin. There are 2 major events that take place in this phase, mitosis, which is the division of the nucleus and cytokinesis, which is division of the cytoplasm. These events overlap one another.

The M phase has 4 phases, prophase, metaphase, anaphase, and telophase.

During prophase chromatin, which is tightly packed DNA and protein, are further condensed to form chromosomes. Spindle fibers also begin to grow from the 2 centrioles pushing them apart to a point where they lie at opposite ends or poles of the cell. The nuclear membrane also disassembles which allows the chromosomes to be moved by the spindle fibers.

During metaphase some of the spindle fibers attatch to the centromeres of the chromosomes, aligning them in the middle of the cell at the equatorial plate.

During the 3rd stage, anaphase, the centromeres that held the sister chromatids together separate, and the sister chromatids are pulled by the spindle fibers toward the poles or ends of the cell. Each sister chromatid is now a chromosome with its own centromere. Cytokinesis also begins at this point.

During telophase, a new nuclear envelop forms around the chromosomes, a nucleolus reforms within the nucleus, the spindle fibers break up and disappear, the chromosomes uncoil to form chromatin and cytokinesis continues.

Once this is complete, 2 new daughter cells are formed and the process of cell division is complete.

Timestamps
0:00 Overview and the 2 types of cell division in the body
0:20 What is mitosis?
0:34 The 2 major phases of the cell division cycle
0:44 Interphase
1:05 The g1 phase
1:15 The s phase
1:31 The g2 phase
1:41 The mitotic phase
2:04 Prophase
2:27 Metaphase
2:37 Anaphase
2:56 Telophase

Видео How Do Cells Divide - Phases Of Mitosis - Cell Division And The Cell Cycle - Cellular Division канала Whats Up Dude