07/12 07 Cell Reproduction and Meiosis Free Online FlashCards

What is the cell cycle?

The cell cycle is the ordered sequence of cell growth, DNA replication, chromosome segregation, and cell division.

What happens during S phase?

DNA is replicated during S phase. Each chromosome then consists of two identical sister chromatids joined at the centromere.

What does mitosis usually produce?

Mitosis usually produces two genetically similar daughter cells with the same chromosome number as the parent cell.

What occurs during mitotic metaphase?

During metaphase of mitosis, chromosomes align at the cell’s equator, with each sister chromatid attached to spindle fibers from opposite poles.

What separates during mitotic anaphase?

In anaphase of mitosis, cohesin is released and sister chromatids separate; each separated chromatid is then an individual chromosome.

How does cytokinesis differ in animals and plants?

Cytokinesis divides the cytoplasm. Animal cells form a cleavage furrow, while plant cells form a cell plate that develops into a new cell wall.

What is the purpose of meiosis I?

Meiosis I separates homologous chromosomes and reduces chromosome number from diploid to haploid.

What happens during prophase I?

During prophase I, homologous chromosomes pair by synapsis to form tetrads. Non-sister chromatids may exchange DNA at chiasmata.

What is crossing over?

Crossing over is the exchange of corresponding DNA segments between non-sister chromatids of homologous chromosomes during prophase I.

Why does independent assortment create variation?

Independent assortment occurs because each homologous pair aligns independently at metaphase I, producing different maternal and paternal chromosome combinations.

What happens to DNA replication between meiosis I and II?

There is no second round of DNA replication between meiosis I and meiosis II.

What is the outcome of meiosis II?

Meiosis II separates sister chromatids in haploid cells, producing four haploid cells by the end of telophase II and cytokinesis.