Prophase II

(Redirected from Prophase ii)

Definition

noun

The first stage in meiosis II highlighted by the disintegration of nucleolus and nuclear envelope, the shortening and thickening of the chromatids, and the replication and movement of centrosomes to polar regions


Supplement

Meiosis is a reproductive cell division since it gives rise to gametes. The resulting cells following meiosis contain half of the number of the chromosomes in the parent cell. That is because the parent cell undergoes two meiotic divisions called first meiotic division (meiosis I) and second meiotic division (meiosis II). Each of them has four major phases. These are prophase, metaphase, anaphase and telophase. Each of these phases is designated as I or II depending where it occurs, i.e. in meiosis I or in meiosis II.

Prophase II is the phase that follows after meiosis I, or after interkinesis if present. If interkinesis takes place, the nuclear envelope and the nucleolus disintegrate during prophase II. The chromosomes are condensed. The centrosomes replicate and move towards the opposite poles. Spindle fibers grow outward from the centrosomes. Prophase II ends where metaphase II begins.

The difference between prophase I and prophase II is that crossing over between chromosomes takes place only in prophase I, not on prophase II.


See also:

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