Problem 12 - Biology of Humans: Concepts, Applications, and Issues

Question

The stage of mitosis during which sister chromatids separate is _____________.

Step-by-Step Solution

Answer

Anaphase

Step 1: Understand the Stages of Mitosis

Mitosis consists of several stages: prophase, metaphase, anaphase, and telophase. Each has distinct characteristics and functions.

Step 2: Identify the Key Action

The action of sister chromatids separating is a specific event. Identify in which stage this separation explicitly happens.

Step 3: Match the Stage with the Action

During anaphase, the sister chromatids are pulled apart to opposite ends of the cell. This is the only stage where this specific action occurs.

Step 4: Conclusion

Since the separation of sister chromatids is the key event in anaphase, the stage of mitosis during which sister chromatids separate is anaphase.

Key Concepts

Mitosis Stages

Mitosis is the process where a single cell divides into two identical daughter cells. Each daughter cell receives the same number of chromosomes as the parent cell. Mitosis is divided into several stages:

• Prophase: This is the first stage of mitosis. Chromosomes condense, becoming visible under a microscope. The nuclear membrane dissolves, and spindle fibers begin to form.


• Metaphase: Chromosomes line up in the middle of the cell. Spindle fibers attach to the centromeres of the chromosomes, ensuring they will be pulled apart correctly.


• Anaphase: This stage is crucial due to the separation of sister chromatids. The spindle fibers shorten, pulling the sister chromatids to opposite sides of the cell.


• Telophase: Chromatids reach the opposite poles of the cell. A nuclear membrane forms around each set of chromosomes, and the cell begins to split.

Understanding each stage is vital for comprehending how cells replicate accurately, ensuring genetic consistency.

Sister Chromatids

Sister chromatids are identical copies of a single chromosome. They are created during the DNA replication phase, which occurs before mitosis begins.

Sister chromatids are joined together by a centromere, ensuring they stay connected until they are ready to be separated. During mitosis, specifically in anaphase, these chromatids are pulled apart by the spindle fibers.

Key points about sister chromatids:

• They are exact genetic copies of one another.
• They remain attached at the centromere until anaphase.
• Separation of sister chromatids ensures each daughter cell gets an identical set of chromosomes.

This accurate distribution is crucial for maintaining the genetic integrity of cells.

Cell Division

Cell division is a fundamental process in all living organisms. It allows for growth, tissue repair, and reproduction. Mitosis is one type of cell division that involves somatic cells (non-reproductive cells).

During cell division, one cell divides to produce two new cells. This process includes multiple stages where the chromosomes are duplicated and evenly distributed between the two daughter cells, ensuring they contain the same genetic material as the original cell.

Significant aspects of cell division include:

• Chromosome Replication: DNA is duplicated so that each new cell will have an exact copy of the genetic material.
• Chromosome Segregation: Chromosomes are carefully divided between the two new cells, involving processes like the separation of sister chromatids.
• Cytokinesis: The final step where the cell's cytoplasm divides, creating two distinct cells.

Understanding cell division is essential for insights into growth, development, and the repair of organisms. It helps explain how genetic information is consistently passed on, ensuring the proper function of cells.