Cell division: Mitosis
What is mitosis?
It's when one cell (called the parent cell) makes an exact copy of itself and produces 2
daughter cells.
Inside a cell there is a nucleus, which holds your DNA, which contains all the “instructions
of how to build you.” That DNA is organized into chromosomes, and in your body cells, or
somatic cells, you have 46 chromosomes grouped into 23 pairs; one in each pair is from
your mother and the other from your father. Cells that have all 46 chromosomes are called
diploid cells because they have 2 sets each. And you also have haploid cells that have half
as many chromosomes (23). Mitosis takes place in a series of stages called interphase,
Prophase , Metaphase, Anaphase ,& Telophase.
Cytokinesis means cell movement.
The discovery of cells
How do new cells form?
• So, they form from existing cells.
• 2 new cells (daughter cells) are made from a parent cell.
• They are identical to the original or parent cell.
The Cell cycle
There are 4 main stages in the cell cycle:
1. The growth of the cell and the production of 2 new daughter cells form
2. Replication of DNA and duplication of chromosomes.
3. Final growth and preparation for division
4. Karyokinesis and cytokinesis.
Karyokinesis: The division of the nucleus.
Cytokinesis: The division of the cytoplasm.
, Interphase: Preparing for Mitosis
• During the cell cycle, a cell spends most of its time growing and preparing for cell
division. This phase is called interphase.
• Interphase consists of the following stages of the cell cycle:
1. Growth and production of new materials
2. Replication of DNA and duplication of chromosomes
3. Final growth and preparation for division
Chromosomes
• When a cell is not dividing, the chromosome
Forms long strands called the chromatin network.
• During interphase, the chromosome appears as a
A group of thin, tangled threads in the chromatin network.
• As the cell gets ready to divide during interphase, each chromosome
copies itself.
• This is to ensure that the new cells formed each have the same number of
chromosomes as the parent cell.
• Each chromosome then consists of two identical strands called chromatids.
• The chromatids are joined together by a structure called a centromere.
• The chromatin network untangles, and individual chromosomes can be seen.
• The long chromatids slowly begin to coil up so that by the time mitosis starts,
they are short and thick.
What is mitosis?
It's when one cell (called the parent cell) makes an exact copy of itself and produces 2
daughter cells.
Inside a cell there is a nucleus, which holds your DNA, which contains all the “instructions
of how to build you.” That DNA is organized into chromosomes, and in your body cells, or
somatic cells, you have 46 chromosomes grouped into 23 pairs; one in each pair is from
your mother and the other from your father. Cells that have all 46 chromosomes are called
diploid cells because they have 2 sets each. And you also have haploid cells that have half
as many chromosomes (23). Mitosis takes place in a series of stages called interphase,
Prophase , Metaphase, Anaphase ,& Telophase.
Cytokinesis means cell movement.
The discovery of cells
How do new cells form?
• So, they form from existing cells.
• 2 new cells (daughter cells) are made from a parent cell.
• They are identical to the original or parent cell.
The Cell cycle
There are 4 main stages in the cell cycle:
1. The growth of the cell and the production of 2 new daughter cells form
2. Replication of DNA and duplication of chromosomes.
3. Final growth and preparation for division
4. Karyokinesis and cytokinesis.
Karyokinesis: The division of the nucleus.
Cytokinesis: The division of the cytoplasm.
, Interphase: Preparing for Mitosis
• During the cell cycle, a cell spends most of its time growing and preparing for cell
division. This phase is called interphase.
• Interphase consists of the following stages of the cell cycle:
1. Growth and production of new materials
2. Replication of DNA and duplication of chromosomes
3. Final growth and preparation for division
Chromosomes
• When a cell is not dividing, the chromosome
Forms long strands called the chromatin network.
• During interphase, the chromosome appears as a
A group of thin, tangled threads in the chromatin network.
• As the cell gets ready to divide during interphase, each chromosome
copies itself.
• This is to ensure that the new cells formed each have the same number of
chromosomes as the parent cell.
• Each chromosome then consists of two identical strands called chromatids.
• The chromatids are joined together by a structure called a centromere.
• The chromatin network untangles, and individual chromosomes can be seen.
• The long chromatids slowly begin to coil up so that by the time mitosis starts,
they are short and thick.
