The kinetochore breaks down and the sister chromatids separate. Sister chromatids line up at the metaphase plate. The kinetochore becomes attached to the cohesin proteins.The nucleus reforms and the cell divides. Cohesin proteins break down and the sister chromatids separate. The kinetochore becomes attached to the mitotic spindle.The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate.Which of the following is the correct order of events in mitosis? (credit âmitosis drawingsâ: modification of work by Mariana Ruiz Villareal credit âmicrographsâ: modification of work by Roy van Heesbeen credit âcytokinesis micrographâ: Wadsworth Center/New York State Department of Health scale-bar data from Matt Russell) The pictures at the bottom were taken by fluorescence microscopy (hence, the black background) of cells artificially stained by fluorescent dyes: blue fluorescence indicates DNA (chromosomes) and green fluorescence indicates microtubules (spindle apparatus). Karyokinesis (or mitosis) is divided into five stagesâprophase, prometaphase, metaphase, anaphase, and telophase.
#Prophase prometaphase metaphase anaphase telophase series
Karyokinesis, also known as mitosis, is divided into a series of phasesâprophase, prometaphase, metaphase, anaphase, and telophaseâthat result in the division of the cell nucleus ( Figure). Revisit the stages of mitosis at this site. The second portion of the mitotic phase, called cytokinesis, is the physical separation of the cytoplasmic components into the two daughter cells. The first portion of the mitotic phase is called karyokinesis, or nuclear division. The mitotic phase is a multistep process during which the duplicated chromosomes are aligned, separated, and move into two new, identical daughter cells. The final preparations for the mitotic phase must be completed before the cell is able to enter the first stage of mitosis. There may be additional cell growth during G 2. Some cell organelles are duplicated, and the cytoskeleton is dismantled to provide resources for the mitotic phase. In the G 2 phase, the cell replenishes its energy stores and synthesizes proteins necessary for chromosome manipulation. Centrioles are not present in the centrosomes of other eukaryotic species, such as plants and most fungi. At the center of each animal cell, the centrosomes of animal cells are associated with a pair of rod-like objects, the centrioles, which are at right angles to each other. The two centrosomes will give rise to the mitotic spindle, the apparatus that orchestrates the movement of chromosomes during mitosis. The centrosome is duplicated during the S phase. In the S phase, DNA replication can proceed through the mechanisms that result in the formation of identical pairs of DNA moleculesâsister chromatidsâthat are firmly attached to the centromeric region. Throughout interphase, nuclear DNA remains in a semi-condensed chromatin configuration. The cell is accumulating the building blocks of chromosomal DNA and the associated proteins as well as accumulating sufficient energy reserves to complete the task of replicating each chromosome in the nucleus.
However, during the G 1 stage, the cell is quite active at the biochemical level. The first stage of interphase is called the G 1 phase (first gap) because, from a microscopic aspect, little change is visible.
The three stages of interphase are called G 1, S, and G 2. In order for a cell to move from interphase into the mitotic phase, many internal and external conditions must be met. During interphase, the cell undergoes normal growth processes while also preparing for cell division.
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