Match the following description with the correct phase of meiosis: line up in the center Metaphase homologous pairs of chromosomes opposite = ends Anaphase spindle fibers pull homologous pairs to Telophase haploid (N) daughter cells form Interphase_ D. cells undergo round of DNA replication Anaphase E; sister chromatids separate from each other Telophase F.2 haploid (N) daughter cells form pairs G, spindle fibers attach to the homologous chromosome Prophase
The Correct Answer and Explanation is:
Here’s the correct matching for each phase of meiosis:
- Line up in the center: Metaphase
- In metaphase I, homologous chromosome pairs align at the metaphase plate. This is a key step in ensuring that each daughter cell will receive one chromosome from each homologous pair.
- Homologous pairs of chromosomes opposite ends: Anaphase
- During anaphase I, the homologous chromosomes are pulled toward opposite poles of the cell by spindle fibers. This is when the homologous chromosomes separate, but the sister chromatids remain attached.
- Spindle fibers pull homologous pairs to: Telophase
- In telophase I, the homologous chromosomes have been pulled to opposite poles, and nuclear membranes begin to reform around each set of chromosomes. The cytoplasm divides (cytokinesis), forming two haploid daughter cells.
- Haploid (N) daughter cells form: Telophase
- By the end of telophase I and cytokinesis, two haploid daughter cells are formed. These cells have half the number of chromosomes as the original cell.
- Cells undergo round of DNA replication: Interphase
- Interphase occurs before meiosis starts and consists of G1, S, and G2 phases. During the S phase, DNA replication happens, ensuring that each chromosome has two sister chromatids at the start of meiosis.
- Sister chromatids separate from each other: Anaphase
- In anaphase II, the sister chromatids of each chromosome are pulled apart toward opposite poles of the cell, ensuring each daughter cell will receive a single chromatid from each chromosome.
- 2 haploid (N) daughter cells form pairs: Prophase
- During prophase I, homologous chromosomes pair up and undergo crossing over, where genetic material is exchanged between chromatids. This is important for genetic diversity. The pairing of homologous chromosomes forms structures called tetrads.
- Spindle fibers attach to the homologous chromosomes: Prophase
- In prophase I, the spindle fibers begin to form and attach to the centromeres of homologous chromosomes, preparing them for alignment during metaphase I.
Explanation:
Meiosis is a two-part cell division process that results in four non-identical haploid cells (gametes), each with half the chromosome number of the original diploid cell.
- Interphase is the preparatory stage before meiosis starts, where DNA replication occurs in the S phase. After replication, chromosomes consist of two identical sister chromatids.
- Prophase I is where homologous chromosomes come together, forming tetrads and undergoing genetic recombination or crossing over. The spindle fibers begin to form and attach to chromosomes.
- Metaphase I is where homologous chromosomes align at the center of the cell.
- Anaphase I is when the homologous chromosomes are pulled apart to opposite poles, but the sister chromatids stay connected.
- Telophase I marks the formation of two haploid daughter cells, each with one copy of each homologous chromosome.
- Anaphase II is when the sister chromatids finally separate, moving to opposite poles in each of the two haploid cells, preparing for the formation of four distinct gametes.
