Cell Cycle and Cell Division
NCERT Class 11 Biology Chapter 10: Cell Cycle and Cell Division (Pages 120–130)
Listen to this article
Summary of Cell Cycle and Cell Division
Cell Cycle and Cell Division at a Glance
CBSE
Class 11
Biology
Biology
10
120–130
6 study resources
Cell Cycle and Cell Division Summary
The cell cycle is essential for life and consists of multiple stages through which a cell progresses before division. It is divided mainly into two phases: interphase and the mitotic phase. Interphase is further categorized into three stages: G1 phase where the cell grows and metabolizes, S phase where DNA replication occurs, and G2 phase where the cell prepares for division. The mitotic phase, or M phase, includes mitosis and cytokinesis. Mitosis is a type of cell division that results in two genetically identical daughter cells. It is divided into four main stages: prophase, metaphase, anaphase, and telophase. During prophase, chromatin condenses to form chromosomes, and the nuclear envelope breaks down. In metaphase, chromosomes align at the cell's equator, preparing for separation. Anaphase involves splitting of sister chromatids, which are pulled to opposite poles, while telophase concludes mitosis with the formation of two nuclei. Cytokinesis follows, completing the cell division process by dividing the cytoplasm and resulting in two distinct cells. In contrast to mitosis, meiosis is a specialized form of cell division occurring in diploid cells to produce haploid gametes. Meiosis includes two sequential divisions: meiosis I and meiosis II. In meiosis I, homologous chromosomes pair and exchange genetic material through a process known as crossing over, increasing genetic variation. This process also ensures that gametes contain half the chromosome number of the parent cell. After meiosis II, four haploid daughter cells emerge, each unique due to recombination events. Both mitosis and meiosis are vital for growth, tissue repair, and reproduction, emphasizing the importance of cell division in the life cycle.
