Mitosis And Meiosis Flashcards
What is mitosis?
Mitosis is a part of the cell cycle in which chromosomes in a cell nucleus (parent cell) are separated into two identical sets of chromosomes, and each set ends up in its own nucleus, (creating two daughter cells).
What are the stages of mitosis? Hint: IPMAT
The stages are interphase, prophase, prometaphase, metaphase, anaphase and telophase.
What occurs during the interphase stage of mitosis?
Interphase is the time during which preparations for mitosis are made. Interphase itself is made up of three phases (G1 phase, S phase, and G2 phase along with a special phase called G0).
What occurs during the stage prophase in mitosis?
During prophase, the nuclear envelope starts to dissociate into small vesicles, and the membranous organelles (such as the Golgi apparatus, and endoplasmic reticulum), fragment and disperse toward the periphery of the cell. The nucleolus disappears. The centrosomes begin to move to opposite poles of the cell.
Microtubules that will form the mitotic spindle extend between the centrosomes, pushing them farther apart as the microtubule fibers lengthen. The sister chromatids begin to coil more tightly with the aid of condensin proteins and become visible under a light microscope.
What occurs during the stage prometaphase during mitosis?
During prometaphase, many processes that were begun in prophase continue to advance. The remnants of the nuclear envelope fragment. The mitotic spindle continues to develop as more microtubules assemble and stretch across the length of the former nuclear area.
What occurs during the stage metaphase during mitosis?
During metaphase, all the chromosomes are aligned in a plane called the metaphase plate, or the equatorial plane, midway between the two poles of the cell. The sister chromatids are still tightly attached to each other by cohesin proteins. At this time, the chromosomes are maximally condensed.
What occurs during the stage anaphase during mitosis?
During anaphase, the cohesin proteins degrade, and the sister chromatids separate at the centromere. Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached. The cell becomes visibly elongated (oval-shaped) as the polar microtubules slide past each other in the region where they overlap, at the midline of the cell.
What occurs doing the stage telophase in mitosis?
During telophase, the chromosomes reach the opposite poles and begin to unravel, relaxing into a decondensed chromatin configuration. The mitotic spindles are depolymerized into tubulin monomers that will be used to assemble cytoskeletal components for each daughter cell. Nuclear envelopes form around the chromosomes, and nucleoli appear within the nuclear area.
