Current Location  >  Biology Topics > Cell Biology > Cell Division Part 1

Cell Division Part 1

Cell Biology - Cell Division Part 1

Definition:
One cell divides and forms two new cells are called cell division

Importance of cell division:
  • Repeated cell division forms the body of an organism
  • Helps in replacement of degenerated and dead cells of body
  • Helps in wound healing
  • Require for formation of reproductive cells

Types of cell division:
1.  Mitosis:
·  Occurs in formation of somatic cells of body
·  The number of chromosomes is the same in new cells as it was in the parent cell


2.  Meiosis:
·  Occurs during formation of reproductive cells
·  The number of chromosomes is reduced to half the number in the parent cell


Cell cycle:
The sequence of events by which the cell is duplicated its contents and divides into two new cells is called cell cycle. The entire process is controlled by genes. Cell cycle is divides into two phases:
·  Interphase
·  Mitotic phase


Interphase:
The phase of cell cycle in which all the cell content gets duplicate and increases the size of cell is called Interphase.
·  Genes are replicated and hence chromosomes are also replicated
·  Chromosomes cannot be observed in their phase as it is dispersed in chromatin   material
·  Centrosome also replicates and two Centriole appear at right angle to each other


Sub-phases of Interphase:
1.  G1 Phase:
·  It is a gap-1 phase and starts at the end of previous cell division.
·  RNA and protein synthesize in this phase

2.  S Phase:
·  It is a synthesis phase and synthesize DNA
·  Replication of chromosome also occurs during this phase

3.  G
2 Phase:
·  It is a gap-2 phase and end of interphase
·  It stops synthesis of DNA


Self Study:
Example- 1:  Match the following

A B
Mitosis Process of one cell divides into two
Meiosis Number of Chromosomes are half
Cell cycle Number of chromosomes are same
Cell division Process of duplication of cell content and division into two cells

Answer:

A B
Mitosis Number of chromosomes are same
Meiosis Number of Chromosomes are half
Cell cycle Process of duplication of cell content and division into two cells
Cell division Process of one cell divides into two

Example-2:  Which of the following phase synthesize RNA and protein?
a)  Mitosis
b)  Meiosis
c)  G
1-Phase
d)  Cell cycle

Answer: G
1-Phase synthesizes RNA and protein.

Example-3: ………….. is a process which replaces degenerated and dead cells of body
a)  Cell molecules
b)  Cell division
c)  Mitosis
d)  Meiosis

Answer: Cell division is a process which replaces degenerated and dead cells of body.

Web-Formulas.com © 2017 | Contact us | Terms of Use | Privacy Policy | Yellow Sparks Network
Web Formulas