Question 1

What happens during prophase II of meiosis?

Accepted Answer

During prophase II, chromosomes thicken and shorten as centrioles move to opposite poles to form the meiotic spindle. The nuclear membrane dissolves, preparing the cell for chromosome alignment. These events mirror mitosis but occur in haploid cells rather than diploid cells.

Question 2

How do sister chromatids separate during anaphase II?

Accepted Answer

The cohesin protein complex holding sister chromatids together breaks down during anaphase II, allowing individual chromatids to move toward opposite poles. These chromatids undergo independent assortment, contributing to genetically unique gamete production and increasing genetic diversity in offspring throughout sexual reproduction.

Question 3

Why are sister chromatids in meiosis II non-identical?

Accepted Answer

Sister chromatids are non-identical because they underwent recombination during meiosis I, exchanging genetic material between homologous chromosomes. This genetic exchange, known as crossing over, ensures that each chromatid carries a unique combination of alleles before they separate in meiosis II.

Question 4

What is the difference between male and female meiosis II?

Accepted Answer

In male meiosis, all four daughter cells receive equal cytoplasm, while female meiosis produces asymmetric cytokinesis, creating one egg cell and a polar body. Additionally, in female oocytes, the meiotic spindle forms without centrosomes, and cyclin A2 stabilizes spindle formation and sister chromatid separation.

Question 5

When does meiosis II begin after meiosis I?

Accepted Answer

Meiosis II can begin immediately after meiosis I without DNA synthesis, or after a brief interval called interkinesis. This timing variation allows the cell to prepare for the second division while maintaining the haploid chromosome number established during meiosis I.

Question 6

What is the final outcome of meiosis II?

Accepted Answer

Meiosis II produces four genetically unique haploid cells through cytokinesis. In animals, these cells function as gametes; in plants, they become spores. Their unique genetic makeup, resulting from recombination and independent assortment, increases genetic diversity in sexual reproduction and organism variation.

Question 7

How does telophase II complete the meiotic cycle?

Accepted Answer

During telophase II, the nuclear envelope reforms and chromatids decondense back into chromatin. Cytokinesis then divides each cell into two haploid daughter cells, completing meiosis with four total haploid gametes ready for sexual reproduction, spore formation, and genetic contribution to offspring.

מיוזה II

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