Chapter 12: Mitosis
The Key Roles of Cell Division
Cell Division
The continuity of life based on the reproduction of cells
o Prokaryotic and Unicellular Eukaryotes
When they divide, they are reproducing
o Multicellular Organisms
Develop from a single cell (fertilized) to a two-celled embryo
Function in renewal and repair in fully grown multicellular eukaryotes
Replace cells that die from normal wear and tear or accidents
Cell Cycle
The life of a cell from the time its first formed during cell division until its own division
into two daughter cells
Concept 12.1: Cell Division Results in Genetically Identical Daughter Cells
Both prokaryotes and eukaryotes most cell division involves the distribution of identical
genetic material (DNA) to two daughter cells
Cellular Organization of the Genetic Material
Genome
o A cells endowment of DNA, it’s genetic information
o Before the cell can divide the genome must be copied or replicated and then the
two copies must be separated to form 2 daughter cells
Chromosomes
o One DNA molecule and associated protein molecules
o Replication and distribution of a lot of DNA is possible because DNA is packaged
in chromosomes
o Eukaryotic Cell
Has multiple, linear chromosomes which are located in the nucleus
o Prokaryotic Cell
Has a single, circular chromosome found in the nucleoid (a region not
enclosed by a membrane)
Chromatin
o The entire complex of DNA and proteins that is the building material of
chromosomes
Somatic Cells
o All body cells except for the reproductive cells
o Ex) humans: 46 chromosomes, made up of two sets of 23
Gametes
o Reproductive cells (sperm and eggs)
o Have one set, half as many chromosomes as somatic cells
o Ex) humans: one set of 23 chromosomes
The Key Roles of Cell Division
Cell Division
The continuity of life based on the reproduction of cells
o Prokaryotic and Unicellular Eukaryotes
When they divide, they are reproducing
o Multicellular Organisms
Develop from a single cell (fertilized) to a two-celled embryo
Function in renewal and repair in fully grown multicellular eukaryotes
Replace cells that die from normal wear and tear or accidents
Cell Cycle
The life of a cell from the time its first formed during cell division until its own division
into two daughter cells
Concept 12.1: Cell Division Results in Genetically Identical Daughter Cells
Both prokaryotes and eukaryotes most cell division involves the distribution of identical
genetic material (DNA) to two daughter cells
Cellular Organization of the Genetic Material
Genome
o A cells endowment of DNA, it’s genetic information
o Before the cell can divide the genome must be copied or replicated and then the
two copies must be separated to form 2 daughter cells
Chromosomes
o One DNA molecule and associated protein molecules
o Replication and distribution of a lot of DNA is possible because DNA is packaged
in chromosomes
o Eukaryotic Cell
Has multiple, linear chromosomes which are located in the nucleus
o Prokaryotic Cell
Has a single, circular chromosome found in the nucleoid (a region not
enclosed by a membrane)
Chromatin
o The entire complex of DNA and proteins that is the building material of
chromosomes
Somatic Cells
o All body cells except for the reproductive cells
o Ex) humans: 46 chromosomes, made up of two sets of 23
Gametes
o Reproductive cells (sperm and eggs)
o Have one set, half as many chromosomes as somatic cells
o Ex) humans: one set of 23 chromosomes
