Cell division
The process by which a cell divides into two "daughter" cells. (Mitosis)
Mitosis
The first stage of division in the cell nucleus.
Cytokinesis
The second stage of division, involves division of the cytoplasm.
Chromatid
One of two identical 'sister' parts of a duplicated chromosome.
Centromere
Area where the chromatids are attached.
Interphase
period of the cell cycle between cell divisions, made of G1, S and G2 phases.
Cell cycle
series of events that cells go through as they grow and divide.
Prophase
The first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions at opposite sides of the nucleus.
Centriole
One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
Spindle fibers
Structure that helps separate the chromosomes during mitosis.
Metaphase
second phase of mitosis during which the chromosomes line up across the middle of the cell
Anaphase
the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles.
Telophase
fourth and final phase of mitosis, during which the nuclear membrane reforms and chromosomes begin to disperse into a tangle of dense material.
Chromosomes
Units that carry genetic information.
Cell plate
This forms only in plant cells during division.
Cancer
Uncontrolled cell growth
cyclins
a family of closely related proteins that regulate the cell cycle.
Meiosis
Cell division that produces reproductive cells in sexually reproducing organisms
Gametes
Sex cells
Haploid cell
A cell containing only one set of chromosomes (n).
Diploid cell
A cell containing two sets of chromosomes (2n), one set inherited from each parent.
Crossing-over
An exchange of genetic material between homologous chromosomes during anaphase I of meiosis; contributes to the genetic variability in gametes and ultimately in offspring.
Independent assortment
Independent segregation of genes during the formation of gametes
tetrads
the paired chromosomes made of four chromatids
Prophase II
The first phase of meiosis II. Prophase II is identical to mitotic prophase, except that the number of chromosomes was reduced by half during meiosis I.
Metaphase II
The second phase of meiosis II. Metaphase II is identical to mitotic metaphase, except that the number of chromosomes was reduced by half during meiosis I.
Anaphase II
The third phase of meiosis II. During anaphase II the sister chromatids are finally spearated at their centromeres and puled to opposite sides of the cell. Note that anaphase II is identical to mitotic anaphase, except the number of chromosmes was reduced
Telophase II
The fourth and final phase of meiosis II. Telophase II is identical to mitotic telophase, except that the number of chromosomes was reduced by half during meiosis. I.
Prophase I
The first phase of meiosis I. During prophase I the replicated chromosomes condense, homologous chromsomes pair up, crossing over occurs between homologous chromosomes, the spindle is formed, and the nuclear envelope breaks apart into vesicles. Prophase I
Metphase I
same stuff happens as in mitosis but it's with tetrads!
Anaphase I
The third phase of meiosis I. the replicated homologous chromosomes are separated (the tetrad is split) and pulled to opposite sides of the cell.
Telophase I
The fourth of meiosis I. Telophase I is identical to mitotic telophase, except that the number of chromosomes is now reduced by half. After this phase the cell is considered to be haploid.