Chapter 10

Which processes lead to most genetic variation in sexually reproducing organisms?

Crossing over Independent assortment of chromosomes in meiosis random fertilization

Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis I and meiosis II?

DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

Meiosis II typically produces _____ cells, each of which is _____.

Four... Haploid

Synapsis occurs during _____.

Synapsis, the pairing of homologous chromosomes, occurs during prophase I.

Meiosis I produces _____ cells, each of which is _____.

Two... Haploid

Homologous chromosomes migrate to opposite poles during _____.

anaphase I

During _____ sister chromatids separate.

anaphase II

During _____ chromosomes align single file along the equator of a haploid cell.

metaphase II Metaphase II is essentially the same as mitotic metaphase except that the cell is haploid.

During _____ a spindle forms in a haploid cell.

prophase II Prophase II is essentially the same as mitotic prophase except that the cells are haploid.

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.

telophase I

At the end of _____ and cytokinesis there are four haploid cells.

telophase II