Anaphase

Definition

Anaphase is a crucial stage in the cell division process where the sister chromatids of each chromosome are pulled apart towards opposite poles of the cell. This separation ensures that each new daughter cell receives an identical set of chromosomes. Anaphase is part of mitosis and meiosis, playing a critical role in maintaining genetic stability and diversity in cellular reproduction.

5 Must Know Facts For Your Next Test

1. Anaphase occurs after metaphase when all chromosomes are aligned at the cell's equator.
2. During anaphase, each sister chromatid is pulled towards opposite ends of the cell by the action of spindle fibers.
3. In mitosis, anaphase results in two genetically identical daughter cells, while in meiosis, it contributes to genetic variation by separating homologous chromosomes.
4. The duration of anaphase is relatively short compared to other phases of cell division, often lasting just a few minutes.
5. Failure in proper separation during anaphase can lead to conditions such as aneuploidy, where daughter cells have an abnormal number of chromosomes.

Review Questions

• How does anaphase ensure genetic stability during cell division?
  • Anaphase ensures genetic stability by accurately separating sister chromatids and pulling them towards opposite poles of the cell. This process guarantees that each daughter cell receives an identical set of chromosomes, which is crucial for maintaining the correct chromosome number. Any errors in this separation can lead to genetic disorders or diseases such as cancer.
• Compare and contrast the role of anaphase in mitosis and meiosis.
  • In mitosis, anaphase results in the separation of sister chromatids to produce two genetically identical daughter cells. In contrast, during meiosis, specifically in meiosis II, anaphase separates sister chromatids like mitosis, but it follows a previous stage (meiosis I) where homologous chromosomes were separated. This difference contributes to genetic diversity in gametes produced by meiosis, while mitosis primarily focuses on producing identical cells for growth or repair.
• Evaluate the consequences of errors during anaphase on organismal health and development.
  • Errors during anaphase can lead to serious consequences such as aneuploidy, where cells end up with too many or too few chromosomes. This condition can result in developmental disorders like Down syndrome or lead to various types of cancer due to uncontrolled cell division. The implications extend beyond individual health, as these errors can impact overall population genetics and evolution if they occur consistently within a species.

Related terms

Chromatid: A chromatid is one half of a duplicated chromosome, which is connected to its sister chromatid by a centromere until they are separated during anaphase.

Spindle Fibers: Spindle fibers are structures that emerge from the centrosomes during cell division and attach to the centromeres of chromosomes, aiding in their movement during anaphase.

Telophase:

Telophase is the final stage of mitosis and meiosis where separated chromosomes reach the poles of the cell and begin to de-condense, leading to the reformation of nuclear membranes.