Main Difference – Telophase 1 vs 2
Telophase 1 and 2 are two events in the meiotic cell division. Meiosis is a special type of cell division that only occurs during the production of sex cells. Meiosis produces four, non-identical sex cells. Meiosis occurs in two stages; meiosis 1 and meiosis 2. Each stage is composed of four steps: prophase, metaphase, anaphase, and telophase. Cytokinesis occurs at the end of each meiotic stage. Telophase 1 is the final step of meiosis 1 while telophase 2 is the final step of the meiosis 2. The main difference between telophase 1 and 2 is that homologous chromosomes are separated from each other during telophase 1 while sister chromatids are separated at the centromere during telophase 2.
Key Areas Covered
1. What is Telophase 1
– Definition, Features, Significance
2. What is Telophase 2
– Definition, Features, Significance
3. What are the Similarities Between Telophase 1 and 2
– Outline of Common Features
4. What is the Difference Between Telophase 1 and 2
– Comparison of Key Differences
Key Terms: Anaphase 1, Anaphase 2, Cell Equator, Homologous Chromosomes, Meiosis 1, Meiosis 2, Sister Chromatids, Spindle Apparatus, Telophase 1, Telophase 2
What is Telophase 1
Telophase 1 is the final stage of the meiosis 1. Telophase 1 follows anaphase 1. During anaphase 1, homologous chromosomes, which are aligned at the cell equator, are separated from each other due to the pull of spindle fibers. A single spindle fiber is attached to the centromere of each chromosome in the homologous pair from one side. Therefore, the contraction of the spindle fiber pulls the chromosome towards the pole of the cell. Each chromosome of the homologous pair moves towards the opposite poles of the cell at the end of anaphase 1. The movement of chromosomes to the each pole is completed during telophase 1.
Figure 1: Telophase 1 and Cytokinesis
At the end of telophase 1, the nuclear membranes reform, the nucleoli reappears, and chromosomes unwind to chromatids. Therefore, two daughter nuclei appear at each opposite pole of the cell. Cytokinesis follows telophase 1, producing two daughter cells. Each daughter cell consists of one chromosome set of the species. These daughter cells then enter the second stage of the meiosis, meiosis 2.
What is Telophase 2
Telophase 2 is the final stage of meiosis 2. Telophase 2 follows anaphase 2. During anaphase 2, sister chromatids are separated from their centromeres and move towards the opposite ends of the cell. Here, two spindle fibers are attached to the same centromere from both sides. Therefore, the contraction of the spindle fibers pulls each sister chromatid to the opposite poles of the cell. The movement of each sister chromatid to the pole is completed during telophase 2. At the end of telophase 2, the nuclear membranes and the nucleoli are reformed, and chromosomes unwind to chromatids. Finally, two daughter nuclei appear at each pole.
Figure 2: Telophase 2 and Cytokinesis
Cytokinesis follows telophase 2, producing two daughter cells. Each daughter cell consists of a sister chromatid from each chromosome of the species. These daughter cells start to specialize into gametes.
Figure 3: Meiosis Overview
Similarities Between Telophase 1 and 2
- Both telophase 1 and 2 are two steps of the meiotic cell division.
- During telophase 1 and 2, the movement of the divided genetic material to the opposite poles of the cell is completed.
- During telophase 1 and 2, the nuclear membranes reform, nucleoli reappears, and chromosomes unwind to chromatids.
- At the end of telophase 1 and 2, two daughter nuclei appear at each opposite pole of the cell.
- The daughter nuclei formed in both telophase 1 and 2 are genetically non-identical.
- The daughter nuclei formed in each telophase are haploid in humans.
- Both telophase 1 and 2 follow cytokinesis, producing two daughter cells.
Difference Between Telophase 1 and 2
Definition
Telophase 1: Telophase 1 is a stage of the first meiotic division in which the complete movement of separated homologous chromosomes to the opposite poles of the cell occurs.
Telophase 2: Telophase 2 is a stage of meiosis 2 in which the complete movement of separated sister chromatids to the opposite poles of the cell occurs.
Occurrence
Telophase 1: Telophase 1 occurs during the meiosis 1.
Telophase 2: Telophase 2 occurs during the meiosis 2.
Movement
Telophase 1: The movement of separated homologous chromosomes to the opposite poles of the cell is completed during telophase 1.
Telophase 2: The movement of separated sister chromatids to the opposite poles of the cell is completed during telophase 2.
Daughter Nuclei
Telophase 1: Each daughter nuclei formed during the telophase 1 consists of a single set of chromosomes of the species.
Telophase 2: Each daughter nuclei formed during the telophase 2 consists of a single set of sister chromatids from each chromosome of the species.
Correspondence to Telophase in Mitosis
Telophase 1: Telophase 1 is not similar to telophase of mitosis.
Telophase 2: Telophase 2 is similar to telophase of mitosis.
Conclusion
Telophase 1 and telophase 2 are two steps of the mitotic division of cells, which occur during the production of gametes. During telophase 1, the movement of separated homologous chromosomes is completed to the opposite poles of the cell. During telophase 2, the movement of sister chromatids is completed to the opposite pole of the cell. At the end of the telophase 1, two daughter nuclei are formed at each opposite pole of the cell, and each daughter nuclei consist of a single set of chromosomes of the species. At the end of the telophase 2, the formed two daughter nuclei consist of a single set of sister chromatids of the species. Therefore, the main difference between telophase 1 and 2 is the events occurring in each step.
Reference:
1. “MEIOSIS TELOPHASE 1.” Course Pics. N.p., n.d. Web. Available here. 31 July 2017.
2. “Telophase I.” Biology-Online Dictionary. N.p., n.d. Web. Available here. 31 July 2017.
3. “Telophase II.” Stages of Meiosis – Online Biology Dictionary. N.p., n.d. Web. Available here. 31 July 2017.
Image Courtesy:
1. “Meiosis Stages” By Ali Zifan – Own work; Used information from Campbell Biology (10th Edition) by Jane B. Reece & Steven A. Wasserman. (CC BY-SA 4.0) via Commons Wikimedia [Cropped] 2. “Meiosis Overview new” By Rdbickel – Own work (CC BY-SA 4.0) via Commons Wikimedia
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