The series of events that cells go through as they grow and divide is known as the cell cycle. The cell cycle consists of several phases, including:
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Interphase: This is the phase where the cell prepares for division and consists of three sub-phases:
- G1 Phase (Gap 1): The cell grows and synthesizes proteins, producing the necessary components for DNA replication.
- S Phase (Synthesis): DNA replication occurs, resulting in the duplication of chromosomes. Each chromosome is now composed of two sister chromatids.
- G2 Phase (Gap 2): The cell continues to grow and prepares for mitosis by producing the required proteins and organelles.
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M Phase (Mitosis): This phase involves the actual division of the cell's nucleus and cytoplasm. Mitosis can be further divided into stages:
- Prophase: Chromosomes condense, spindle fibers form, and the nuclear envelope begins to break down.
- Metaphase: Chromosomes align at the cell's equatorial plane.
- Anaphase: Sister chromatids are pulled apart to opposite poles of the cell.
- Telophase: Nuclear envelopes re-form around the two sets of chromosomes, which begin to de-condense.
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Cytokinesis: This is the final step following mitosis where the cytoplasm divides, resulting in two daughter cells.
In plants, cytokinesis involves the formation of a cell plate, which develops into the new cell wall that separates the two daughter cells.
Mutations can occur during the cell cycle, particularly during DNA replication in the S phase. These changes in the DNA sequence can affect the function of genes and potentially lead to various biological consequences, including cancer if they occur in key regulatory genes.
In summary, the cell cycle is a critical process that involves growth, DNA replication, and cell division, with specific events such as the S phase, where DNA is synthesized, and the production of a cell plate in plant cells during cytokinesis. Mutation can impact the cell cycle and lead to various outcomes.
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