What is happening during prophase 2?
Concept 10: Meiosis II: Prophase II. Meiosis II begins without any further replication of the chromosomes. In prophase II, the nuclear envelope breaks down and the spindle apparatus forms. To replay the prophase II animation, click the Replay button.
2. What is the difference between prophase of mitosis and prophase 1 of meiosis? Meiosis= homologous chromosomes each composed of 2 sister chromosomes come together as pairs. The resulting structure, consisting of four chromatids, is called a tetrad.
- Meiosis II begins without any further replication of the chromosomes. In prophase II, the nuclear envelope breaks down and the spindle apparatus forms. While chromosome duplication took place prior to meiosis I, no new chromosome replication occurs before meiosis II. The centrioles duplicate.
- This can happen either during meiosis I or meiosis II. If nondisjunction occurs during anaphase I of meiosis I, this means that at least one pair of homologous chromosomes did not separate. The end result is two cells that have an extra copy of one chromosome and two cells that are missing that chromosome.
- Concept 4: Meiosis I: Prophase I. Chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears. To see prophase I animated, click the Play button. At the start of prophase I, the chromosomes have already duplicated.
-Prophase--nuclear envelope breakdown, chromosome condensation, spindle formation. -Metaphase--chromosomes are lined up precisely on the metaphase plate, or middle of the cell. -Telophase--chromatids begin to decondense and become chromatin. Spindle disappears.
- During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles (sides) of the cell. The spindle starts to form during prophase of mitosis.
- Mitosis takes place in four stages: prophase (sometimes divided into early prophase and prometaphase), metaphase, anaphase, and telophase. You can learn more about these stages in the video on mitosis. In cytokinesis, the cytoplasm of the cell is split in two, making two new cells.
- There three stages in interphase occur in a particular order as part of the cell cycle; cells spend a majority of this cycle in interphase.
- The Purpose of Interphase. While prokaryotic cells, like bacteria, replicate through binary fission, eukaryotic cells divide through mitosis or meiosis.
- G1 Stage.
- S Phase.
- G2 Stage.
Updated: 18th November 2019