G1, S, G2 phase
Q. list the name of Mitotic phase steps
prophase, prometaphase, metaphase, anaphase and telophase
Q. why do cells divide?
the cells need to reproduct, grow and repair
Five facts
1. during all three subphases,(interphase) the cell grows by producing proteins and cytoplasmic organelles such as mitochondria and endoplasmic reticulum.
2. during interphase, cell is in a resting phase, and performing DNA replicates; organelles double in number and prepare for division
3. during prophase, the spindle forms, centrioloes move to opposite poles and chromosomes become visible
4. during metaphase, chromosomes line up along the equator and anaphase, centromeres divide, chromatids separate and move to opposite poles.
5. during telophase, nuclear membrane forms around the chromosomes, two nuclei form in the cell and cytokinesis begins.
10 key terms
1.
cell division
the reproduction of cells
2.
genome
a cells' endowment of DNA, its genetic information
3.
sister chromatid
each duplicated chromosomes has two of them, the two chromatid, each containing an identical DNA molecule, are initially attached all along their lengths by adhesive protein complexes called cohesion.
4.
chromatin
a complex of DNA and associated protien molecules
5.
interphase
mitotic cell division alternates with a much longer stage
6.
cytokinesis
the division of the cytoplasm
7.
mitosis
the division of the nucleus
8.
aster
a radial array of short microtubules
9.
centrosome
a subcellular region containing material that functions throughout the cell cycle to organize the cell's microtubules
10.
kinetochore
a structure of proteins associated with specific sections of chromosomal DNA at the centromere
diagram
The beginning of mitosis is called prophase. In early prophase, the centrosomes move toward opposite poles of the cell, organizing the spindle microtubules between them. The sister chromatids become visible in the nucleus as they condense.
The chromatids remain lined up between the poles of the cell during metaphase
Anaphase begins when the pairs of sister chromatids separate
The separated chromatids are now called chromosomes, and move toward the poles of the cell. The chromosomes arrive at the poles in telophase, and new nuclear membranes form around them.
video
http://www.youtube.com/watch?v=lf9rcqifx34
summary
Interphase is made up of three distinct phases: G1, S phase, and G2. The G1 and G2 phases serve as checkpoints for the cell to make sure that it is ready to proceed in the cell cycle. If it is not, the cell will use this time to make proper adjustments that can include cell growth, correction or completion of DNA synthesis, and duplication of intracellular components. S phase involves the replication of chromosomes. All three stages of interphase involve continued cell growth and an increase in the concentration of proteins found in the cell.
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