Question

(iii) during the pre-mitotic gap phase (g2), synthesis of rna and protein continues, but dna synthesis stops. The durations of the s phase, the g2 phase and mitosis is generally constant in most cell types. The length of g1 phase is usually variable. Cells that do not divide frequently have a longer g1 phase, while frequently dividing cells have a shorter g1 phase. During g1 phase, a cell may follow one of the three options: (a) cell may

Answer 1









Introduction to Cell Cycle and Cell Division



Meiosis I Prophase I and Metaphase I Hin

 

Cell Cycle

Cell cycle and cell division form the basis of life. Growth, regeneration, and reproduction depend upon cell cycle and cell division. However, what happens when this cell cycle is disturbed or when the cells fail to regulate the cell cycle? It can lead to uncontrolled cell growth and the division which can finally lead to cancer

Scientists and microscopists have known cell cycle and cell division for over hundred years. However, it was the pioneering and revolutionary work of Alma Howard and Stephen Pelc in the 1950s that revealed DNA replication took place at a particular phase of the cell cycle. They demonstrated that cell cycle is distinct and separate from the mitosis process.

Definition

Cell cycle (cell division cycle) is an ordered sequence of events occurring in a cell. Cell cycle results in cell growth and DNA replication thereby forming two daughter cells. It is an essential process for the formation of a mature organism from single-celled fertilized eggs. The process of cell cycle promotes renewal and regeneration of hair, blood cells, skin, and certain internal organs. The formation of daughter cells by cell division indicates the start of a new interphase cycle.