Lab 3: The Cell Cycle and Mitosis PDF

Cell biology The Cell Cycle and MITOSIS Vienna Marie Echalar Dumlao RMT, MLS (ASCP), MIB  Understand the stages of the cell cycle and their significance in the life of a cell. Explain the role of checkpoints in the cell cy...

Cell biology The Cell Cycle and MITOSIS Vienna Marie Echalar Dumlao RMT, MLS (ASCP), MIB  Understand the stages of the cell cycle and their significance in the life of a cell. Explain the role of checkpoints in the cell cycle and how they regulate cell division. Identify and describe the phases of mitosis and the key events in Learning each phase. Outcomes  All cells are produced through the Cell 1 process of cell division, during which one cell splits into two. To divide, a cell must complete several 2 important tasks: it must grow, copy its genetic material (DNA), and physically split into two daughter cells. Cells perform these tasks in an 3 organized, regulated series of steps known as the cell cycle.  The cell cycle is split into two primary phases: interphase and the mitotic (M) phase. The mitotic phase is when the cell During interphase, the cell divides. During the M phase, the grows and replicates (makes a copy of) each of its 2 cell separates its chromosomes into two sets and then divides its 1 chromosomes. cytoplasm, forming two genetically identical daughter cells.  Interphase The G phase is when a cell does most of its growing, which requires the cell to take in extra nutrients. During this phase, the cell increases in size, and synthesizes new proteins and organelles. The S phase (synthesis phase) is when a cell replicates its DNA. At the end of this phase, the cell contains a complete copy of each of its chromosomes. During the G phase, the cell grows even more and continues to synthesize proteins and organelles. In particular, the cell makes many of the molecules and structures required for the process of cell division, and it also begins to reorganize its contents in preparation for the M phase. Cell reproduction It is a fundamental process to create life, occurring in all forms of it, ensuring the perpetuity of their existence, as well as growth, tissue replacement, and reproduction in multicellular organisms. It is known as cell reproduction or cell division, is the stage in the cell cycle where each cell divides to form two daughter cells. There are three biological mechanisms of cell reproduction: binary fission, meiosis, and mitosis. Cell reproduction  Mitosis When mitosis is completed, It is the most common form 1 2 two genetically identical cells of cell division in somatic are produced. It is a eukaryotic cells (those that fundamental process during will not become sex cells). growth and tissue repair. Mitosis  Centrosome Interphase The period between two consecutive mitoses is called interphase. As the cell prepares for reproduction, it duplicates its DNA and takes the necessary internal and external measures to successfully undergo the process. A cell divides into two daughter cells that can then divide again, creating a cycle of cell division. Deoxyribonucleic Acid (DNA)  Prophase Centrosome Chromosomes The nuclear envelope starts to break down, gradually dissolving. Chromatin undergoes progressive condensation due to supercoiling, resulting in the formation of chromosomes. The centrosome duplicates, and each one moves to one of the cell's ends, where microtubules are formed. Microtubules Centrosome Microtubules Metaphase The chromosomes align at the cell's equator during metaphase, with the fibers of the mitotic spindle. Microtubules attach to each centromere of the chromosomes. Each chromosome has already duplicated during interphase, so at this point, the two copies separate. Centromere Chromosome  Anaphase Centrosome Chromosome It is the crucial phase of mitosis because it is when the distribution of the original genetic information occurs. The two groups of chromosomes (which are identical) move apart thanks to the microtubules toward opposite poles of the cell. Each set of genetic information concentrates around a centrosome. Microtubules Centrosome Microtubules Telophase The microtubules that aided in the migration of the two groups of chromosomes disappear. The chromosomes start to decondense, exposing the DNA and initiating the processes characteristic of an independent cell. Two new nuclear envelopes begin to form, each containing the information for each new cell. Deoxyribonucleic Acid (DNA)  Cytokinesis Contractile ring It involves the physical separation of the cytoplasm. A contractile ring composed of actin and myosin microfilaments forms, constricting the cell and creating a structure resembling an hourglass. A cleavage furrow forms, ultimately separating the two daughter cells, each with the same number of chromosomes as the parent cell. Mitosis  Cancer Cancer is a term that describes many different diseases caused by the same problem: uncontrolled cell growth. Most cancers occur due to a series of mutations that make them divide more quickly, bypass checkpoints during cell division, and avoid apoptosis (programmed cell death). Generally, mutations of two types of cell cycle regulators can promote the development of cancer: Positive regulators, which normally promote cell growth, may become hyperactivated (oncogenic). Negative regulators (tumor suppressors), which prevent the formation of tumors, may become inactivated. BIO 102 END