Question

Match the statement to interphase or the phase of mitosis in the key. a. metaphase b. interphase c. telophase d. prophase e. anaphase. Centromere splits and sister chromosomes move to opposite poles.

Short answer

The correct match for the statement "Centromere splits and sister chromosomes move to opposite poles" is anaphase (Option e).

Step-by-step solution

Understand the cell cycle and its phases

The cell cycle consists of interphase and mitosis. Interphase is the period when the cell grows and prepares for cell division by replicating its DNA. Mitosis is the actual process of dividing chromosomes and splitting the cell into two new cells. Mitosis is further divided into four phases: prophase, metaphase, anaphase, and telophase.

Analyze the statement

The given statement mentions that the centromere splits and sister chromosomes move to opposite poles. This event takes place during a specific phase of mitosis.

Identify the correct phase

The event described in the statement occurs during anaphase. In this phase, the sister chromatids are pulled apart by the spindle fibers and move towards the opposite poles of the cell.

Match the statement with the correct option

We have identified the correct phase as anaphase. Looking at the options given in the exercise: a. metaphase b. interphase c. telophase d. prophase e. anaphase We can match the statement to the appropriate phase (option 'e') as follows: Centromere splits and sister chromosomes move to opposite poles -> anaphase (Option e)

Key concepts

Interphase: The Preparation Phase

Interphase is critical yet less dramatic than the actual division stages of the cell cycle. It sets the stage for mitosis and is split into three substages: G1 (Gap 1), S (Synthesis), and G2 (Gap 2). During G1, the cell grows in size, while in the S phase, the cell’s DNA is replicated. Finally, in the G2 phase, further growth occurs and the cell prepares necessary proteins and organelles for cell division.

Imagine interphase as the 'behind-the-scenes' groundwork, where the cell meticulously doubles its DNA content, ensuring that, upon division, each new cell retains a full set of genetic instructions. Hence, in the given exercise, option 'b'—interphase—represents all these preparatory events leading up to mitosis.

Mitosis: The Division Dilemma

Mitosis is a form of cell division vital for growth and healing in multicellular organisms. It's the point at which the replicated DNA and cytoplasmic contents are separated, and the cell divides into two daughter cells. Mitosis consists of four distinct phases: prophase, metaphase, anaphase, and telophase.

In prophase, chromosomes condense and become visible while the nuclear membrane starts to disintegrate. During metaphase, chromosomes align at the cell's equator. Anaphase, which the exercise mentions, sees chromosomes split at the centromeres before moving to opposite poles. Lastly, in telophase, the cell finalizes division by re-forming nuclear membranes and beginning to return to a normal state. It's essential to visualize mitosis as an orderly sequence of steps that ensures genetic material is equally distributed, preserving the fidelity of the cell's information for future generations.

Anaphase: The Pulling Apart

Anaphase stands out in mitosis as the phase when duplicated chromosomes are pulled apart by spindle fibers. It is the answer to our exercise problem, marked as option 'e'.

In anaphase, spindle fibers attach to the kinetochores of sister chromatids, and once the centromeres split, the sister chromatids are pulled towards the opposite poles of the cell. This action guarantees that each new daughter cell will receive an identical set of chromosomes. Visualize it as a tug-of-war where each side pulls with equal force to ensure an even distribution of genetic material. This exact precision is crucial for the maintenance of chromosomal integrity across successive cell generations.