Binary Fission.

Only available on StudyMode
  • Download(s) : 455
  • Published : October 4, 2010
Open Document
Text Preview
Binary fission begins with DNA replication. DNA replication starts from an origin of replication, which opens up into a replication bubble (note: prokaryotic DNA replication usually has only 1 origin of replication, whereas eukaryotes have multiple origins of replication). The replication bubble separates the DNA double strand, each strand acts as template for synthesis of a daughter strand by semiconservative replication, until the entire prokaryotic DNA is duplicated. After this replicational process, cell growth occurs.

Each circular DNA strand then attaches to the cell membrane. The cell elongates, causing the two chromosomes to separate. Cell division in bacteria is controlled by the septal ring, a collection of about a dozen proteins that collect around the site of division. There, they direct assembly of the division septum.the cell wall and plasma membrane starts growing transversely from near the middle of the dividing cell. The dividing septum originates centripetally and separates the parent cell into two nearly equal daughter cells ,each having a nuclear body [1] The stages in the cell cycle are: 

1. Interphase
3.Cytokinesis (This is a seperate process that begins at the same time as telophase) 

Different Stages in the Process of Meiosis

There are two stages of meiosis, namely, meiosis I and meiosis II. The parent cell or the dividing cell undergoes a preparatory phase, known as interphase, before entering the two stages of meiosis. In the interphase, the parent cell synthesizes more DNA (deoxyribonucleic acid) andproteins, increasing the overall size and mass of the cell. As a part of the preparatory phase, the dividing cell duplicates or doubles its chromosomes. With these major changes, the parent cell enters the first stage of meiosis. Following is a brief discussion about the two stages and their phases. 

Meiosis I: Meiosis I is divided into four phases, which are as follows:...
tracking img