Cell Cycle and Cell Division Introduction

Cell Cycle

The cell cycle is a series of events that occur in a cell's life, leading to its growth, replication, and division into two daughter cells. It is a highly regulated and sequential process crucial for the maintenance, growth, and reproduction of multicellular organisms. The cell cycle consists of distinct phases, each serving specific functions.

  1. Interphase:

    • G1 Phase: The cell grows and carries out its normal functions.
    • S Phase: DNA synthesis occurs, resulting in the replication of genetic material.
    • G2 Phase: Continued growth and preparation for cell division.
  2. Mitosis (M Phase):

    • Prophase: Chromosomes condense, and the nuclear envelope breaks down.
    • Metaphase: Chromosomes align at the metaphase plate.
    • Anaphase: Sister chromatids separate and move towards opposite poles.
    • Telophase: Chromatids arrive at poles, and new nuclear envelopes form.
  3. Cytokinesis:

    • The division of the cell's cytoplasm and organelles to produce two daughter cells.
    • In animal cells, a cleavage furrow forms.
    • In plant cells, a cell plate develops into a new cell wall.

Cell Division

Cell division is the process by which a parent cell divides into two or more daughter cells. There are two main types of cell division:

  1. Mitosis:

    • Results in the production of two genetically identical daughter cells.
    • Essential for growth, tissue repair, and asexual reproduction.
    • Maintains the chromosome number (diploid) in daughter cells.
  2. Meiosis:

    • Occurs in specialized cells for the formation of gametes (sperm and egg cells).
    • Involves two sequential divisions, resulting in four non-identical haploid cells.
    • Introduces genetic diversity through processes such as crossing over.