During prophase II of meiosis II, four important steps occur. These are the condensing of chromatin into chromosomes, disintegration of the nuclear envelope, migration of centrosomes to either pole, and the reconstruction of the spindle apparatus.
What are the 2 very important things that happen during prophase 1?
During prophase I, the homologous chromosomes condense and become visible as the x shape we know, pair up to form a tetrad, and exchange genetic material by crossing over. During prometaphase I, microtubules attach at the chromosomes’ kinetochores and the nuclear envelope breaks down.
What does prophase II mean?
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. … prophase.
What happens in prophase 1 and not 2?
Prophase 1 is the initial phase of meiosis 1 and prophase 2 is the initial phase of meiosis 2. … The main difference between prophase 1 and 2 is that genetic recombination occurs through crossing overs and the “Chiasmata” formation during prophase 1 whereas no genetic recombination is noticed at the prophase 2.
Is there crossing over in prophase 2?
Crossing over does not occur during prophase II; it only occurs during prophase I. In prophase II, there are still two copies of each gene, but they are on sister chromatids within a single chromosome (rather than homologous chromosomes as in prophase I).
Which event occurs during meiosis II but not during meiosis?
In meiosis II, these chromosomes are further separated into sister chromatids. Meiosis I includes crossing over or recombination of genetic material between chromosome pairs, while meiosis II does not.
What important event occurs in prophase 1?
During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. Chromosomal condensation allows these to be viewed in the microscope.
What is telophase II?
Telophase II is the stage in meiosis II that follows after anaphase II. In anaphase II, the sister chromatids that were formerly joined at the centromere are separated from each other and moved away to opposite poles. … The complete movement and separation of sister chromosomes mark the telophase II.
How many chromosomes will be in a cell in prophase II?
From Prophase-II to Telophase-II cells are in haploid (n) state. Cells in metaphase-II phase is haploid (n). So, the number of chromosomes in the cell at this phase is 10 .
Which events occur twice during meiosis?
Answer: Since cell division occurs twice during meiosis, one starting cell can produce four gametes (eggs or sperm). In each round of division, cells go through four stages: prophase, metaphase, anaphase, and telophase.
Which characteristic seen in prophase 1 does not occur in prophase 2?
C) During prophase I the chromosomes coil up; the chromosomes are not coiled up during prophase II.
Why is there no real need for interphase II between telophase I and prophase II?
Once meiosis starts, the purpose is to produce a haploid gamete. So there is no further need of replication or growth. Hence between meiosis I and meiosis II , there is no interphase.
Why is metaphase 2 important?
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.
Which event takes place during anaphase II of meiosis?
What happens during anaphase II of meiosis? Sister chromatids separate from each other and migrate to opposite ends of the cell.
What does a centrosome look like?
Centrosomes are made up of two, barrel-shaped clusters of microtubules called “centrioles” and a complex of proteins that help additional microtubules to form. This complex is also known as the microtubule-organizing center (MTOC), since it helps organize the spindle fibers during mitosis.
What would happen if crossing over occurred between sister chromatids?
Terms in this set (27) What would happen if crossing over occurred between sister chromatids? Nothing would happen because sister chromatids are genetically identical or nearly identical.