2.3 Cell Division Flashcards
An important activity of all kinds of cells
Cell division
The division of cells in animals body
Allows animals ( and us) to grow
Replaced old cells that die
Mitosis
Produce two diploid (2n) somatic cells that are genetically identical to each other and the original parent cell
Mitosis
Before a dividing cell enters mitosis, it undergoes a period of growth called interphase. About 90 percent of a cell’s time in the normal cellcycle may be spent in interphase.
This is the non-mitotic stage.
Interphase
The period prior to the synthesis ofDNA. In this phase, the cell increases in mass in preparation for cell division.
The first gap phase
G1 phase
The period during whichDNA is synthesized.
S phase
The period after DNA synthesis has occurred but prior to the start of prophase
G2 phase
During this period structural changes of chromosomes are visible.
M phase
M phase may be subdivided into four stages,
Prophase, Metaphase, Anaphase and Telophase
This stage is characterized by the appearance of coiled, contracted threads – the chromosomes. The chromosomes are longitudinally double, each half is a chromatid. The chromatin condenses into discrete chromosomes.
Prophase
the spindlereaches maturity and the chromosomes align at the metaphase plate
Metaphase
the paired chromosomes (sister chromatids) separate and begin moving to opposite ends (poles) of the cell.
Anaphase
is accomplished by the formation of a cell plate, as the chromosomes separate during anaphase, the cytoplasm divides and the cytoplasmic contents are distributed.
Cytokinesis
In sexually reproducing organisms, the special kind of cell division whereby the chromosomes number of the cells is reduced to half its usual number.
Meiosis
This process, in which homologous chromosomes trade parts is called
Crossing over
