MARIO LUNA

Mitosis

INTERPHASE : In G1 the cell growsS Phase : The period during which DNA is synthesized. In most cells, there is a narrow window of time during which DNA is synthesized. In the latter part of interphase, the cell still has nucleoli present.

ProphaseEach duplicated chromosome is seen as a pair of sister chromatids joined by the duplicated but unseparated centromere.

The nucleolus disappears during prophase.

In the cytoplasm, the mitotic spindle, consisting of microtubules and other proteins, forms between the two pairs of centrioles as they migrate to opposite poles of the cell.

Metaphase

The centrosomes are at opposite poles of the cell.

For each chromosome, the kinetochores of the sister chromatins face the opposite poles, and each is attached to a kinetochore microtubule coming from that pole.

ANAPHASEAnaphase begins when the duplicated centromeres of each pair of sister chromatids separate, and the now-daughter chromosomes begin moving toward opposite poles of the cell due to the action of the spindle.

Spindle fiber pull daughter chromosomes towards the poles

TELOPHASE

Chromosomes become less visible.

The nuclear envelopes of these nuclei are formed from remnant pieces of the parent cell's nuclear envelope and from pieces of the endomembrane system.

Chromatin fibers of chromosomes uncoil.

CYTOKINESIS

Cytoplasm divides.

Two new daughter cells.

MEIOSIS

Interphase: genetic material is duplicated.

Meiosis involves a reduction in the amount of genetic material.

Prophase1

Duplicated chromatin condenses. Each chromosome consists of two, closely associated sister chromatids. Crossing over can occur during the later part of this stage.

The nucleolus disappears.

Prophase I is the longest phase of meiosis consuming 90% of the time for the two divisions.

Metaphase 1

Homologous chromosomes align at the equatorial plate.

The centrioles are at opposite poles of the cell.

Spindle fibers from one pole of the cell attach to one chromosome of each pair, and spindle fibers from the opposite pole attach to the homologous chromosome.

ANAPHASE 1

Homologous pairs separate with sister chromatids remaining together.

Sister chromatids remain attached at their centromeres and move together toward the poles.

Telophase 1

Two daughter cells are formed with each daughter containing only one chromosome of the homologous pair.

CYTOKINESIS

Two cells that are 2 N