Cell Cycle and Cell Division

Cell Cycle

• Each new cell is formed by division of its parent cell.
• The series of changes that a cell undergoes from the time it forms until it divides is called the cell cycle.
• In other words, cell undergoing the process of Growth, development and reproduction is called cell cycle.
• For a cell to get divided, the cell must grow, synthesise materials like proteins, RNA, DNA etc. before splitting into two daughter cells.
• The duration of one cell cycle is known as Generation time.
• Hence, The cell cycle is a series of events that takes place in a cell leading to the duplication of its DNA and subsequent division of the cell to produce two daughter cells.

Phases of Cell Cycle

• The cell cycle has been divided into two phases –
  • Non dividing phase called INTERPHASE
  • Dividing phase called M-PHASE or mitosis

Interphase

• • Non-dividing phase or preparatory phase.
  • Lies between two successive cell division. The daughter cells produced from a mother cell are small, with less cytoplasm and full sized nucleus.
  • During this phase, before entering the division , cell prepares itself for division by –
    • • Synthesis of Protein for cell division
      • Replicating its DNA molecule
      • Forming Daughter chromatids from DNA and histones
  • Interphase is divided into 3 phases, namely –
    • • G₁ phase – first Growth Phase
      • S phase – Synthesis Phase
      • G₂ Phase – Second Growth Phase

Phases of Interphase

Cell Division

• Cell Division is a process by which parent cell divides into two identical daughter cells.
• The daughter cell has the exact copy of the hereditary materials their parent cells.
• The Cell division helps in growth, repair and reproduction.

Types of Cell Division

• • The cell Division are of two types –

1. 1. 1. Mitosis – cell division for growth and development. Leads to diploid cells.
      2. Meiosis – cell division leading to the production of Gametes. Leads to haploid cells

• • Each cell division is divided into two phases –

1. 1. 1. Karyokinesis – division of Nucleus
      2. Cytokinesis – division of the Cytoplasm

After the division of the cytoplasm, cell division is completed with the formation of two daughter cells.

Need of Division

• • Growth – all multi cellular organism begins life with single cell. This single cell divides and replicates to produce the whole organism. This is due to the increase in number of cell.
  • Repair – new cells are needed for healing wounds or to replace the damaged tissues etc.
  • Replacement – our body constantly sheds cells which dies, to replace them cell division is required.
  • Reproduction – essential for reproduction in living organisms.

Difference b/w Cell Cycle & Cell Division

So, this was all about the Cell Cycle, Cell Division and types of Cell Division and Interphase.

In the Next Post (Click here), we will discuss about the Mitosis – Somatic cell division.