Definitions [3]
Definition: Cell Cycle
The cell cycle is a series of events that take place in a cell leading to the duplication of its DNA and the subsequent division of the cell to produce two daughter cells.
Define the following term:
Aster
The centrosome (in animal cell) splits into two along with the simultaneous duplication of the centrioles contained in it. The daughter centrioles move apart and occupy opposite "poles" of the cell. Each centriole is surrounded by radiating rays and is termed an aster (aster : star).
Define cell division.
Cell division is one of the most fundamental characteristics of life. This is the method which enables life to perpetuate generation after generation.
Key Points
Key Points: Cell Cycle
- The cell cycle is the sequence of events in which a cell grows, duplicates its DNA, and divides into two daughter cells.
- Cell division is essential for growth and reproduction in all living organisms, starting from a single cell.
- A single cell forms a large organism through repeated cycles of growth and division, producing many cells.
- DNA replication and cell growth must be coordinated to ensure that daughter cells receive a complete and correct genome.
- Cell growth is continuous, but DNA synthesis occurs only at a specific stage of the cell cycle, followed by the distribution of chromosomes during division.
Key Points: Cell Division
- Cell division is a vital process for growth, repair, and the formation of new organisms, helping maintain life in all living beings.
- It occurs in two forms: mitosis (in somatic and stem cells) for producing diploid identical cells, and meiosis (in germ cells) for forming haploid gametes.
- Mitosis supports body growth and tissue repair, while meiosis ensures genetic variation and maintains chromosome number in reproduction.
- Before division, the cell’s chromosome number doubles (e.g., from 2n to 4n) to ensure accurate distribution during mitosis or meiosis.
