CELLS alive!-Meiosis Phase Worksheet
The correct answer and explanation is:
The CELLS alive!-Meiosis Phase Worksheet requires identification of the phases of meiosis and a detailed understanding of the process. Let’s analyze and answer:
Answers to Phases of Meiosis:
- Prophase I
Homologous chromosomes pair up and exchange genetic material through crossing over. - Metaphase I
Homologous chromosome pairs align at the metaphase plate. - Anaphase I
Homologous chromosomes are pulled apart to opposite poles. - Telophase I and Cytokinesis
Two haploid cells form, each with one chromosome from each homologous pair. - Prophase II
Chromosomes condense again in the two haploid cells formed earlier. - Metaphase II
Chromosomes align individually along the metaphase plate in each haploid cell. - Anaphase II
Sister chromatids are pulled apart to opposite poles. - Telophase II and Cytokinesis
Four genetically distinct haploid cells are produced.
Explanation :
Meiosis is a type of cell division that reduces the chromosome number by half, producing four haploid gametes. It ensures genetic diversity through processes like crossing over and independent assortment.
Meiosis I is the reductional division where homologous chromosomes separate. In Prophase I, homologous chromosomes undergo synapsis, forming tetrads. This phase also allows crossing over, which exchanges DNA segments between homologous chromosomes, creating genetic variation. During Metaphase I, homologous pairs line up at the cell’s equator. Anaphase I separates homologs, reducing the chromosome number. Finally, in Telophase I and Cytokinesis, two haploid cells form.
Meiosis II resembles mitosis but starts with haploid cells. Prophase II sees chromatin condense into chromosomes. In Metaphase II, chromosomes align individually at the metaphase plate. Anaphase II separates sister chromatids, ensuring each daughter cell gets an identical chromatid. Telophase II and Cytokinesis finalize meiosis, creating four haploid cells, each with unique genetic combinations.
This process is critical for sexual reproduction. The genetic variability introduced during meiosis increases evolutionary adaptability, contributing to species survival.