Question

Match the statement to interphase or the phase of mitosis in the key. a. metaphase b. interphase c. telophase d. prophase e. anaphase. Cytokinesis occurs during this phase.

Short answer

Cytokinesis occurs during telophase (c).

Step-by-step solution

Understand Cytokinesis

Cytokinesis is the physical division of a cell into two daughter cells following nuclear division (mitosis). It occurs after mitosis has been completed and the cell has two nuclei.

Understand Interphase

Interphase is the period in the cell cycle when the cell is preparing for mitosis. During interphase, the cell grows, replicates its DNA, and prepares for cell division. Interphase is not part of mitosis.

Analyze the Phases of Mitosis

Mitosis is divided into the following phases: a. Prophase: Chromosomes become visible, and the nuclear envelope disappears. b. Metaphase: Chromosomes align at the center (equator) of the cell. c. Anaphase: Chromosomes separate and move towards the poles of the cell. d. Telophase: Chromosomes reach the poles, and the nuclear envelope reforms.

Identify the Phase of Mitosis Where Cytokinesis Occurs

Cytokinesis occurs during late anaphase and continues throughout telophase. It is the final stage of mitosis, and it ensures that the two daughter cells receive equal amounts of cytoplasm and genetic material.

Match the Statement to the Relevant Phase of Mitosis or Interphase

The given statement "Cytokinesis occurs during this phase" matches with "telophase", as cytokinesis starts in late anaphase and continues throughout telophase. Therefore, the correct answer is: c. Telophase

Key concepts

Cytokinesis

Cytokinesis is an essential process in cell division where the cell splits into two daughter cells. It is different from mitosis, which involves the division of the cell's nucleus. Cytokinesis follows nuclear division and ensures that each daughter cell receives the necessary cellular components and genetic material.
After mitosis completes with the formation of two nuclei, cytokinesis begins. This process is particularly crucial because it provides each daughter cell with equal parts of the cell's organelles and cytoplasm.

• In animal cells, cytokinesis occurs through a process known as cleavage. This involves the pinching of the cell membrane to create two separate cells.
• In plant cells, a structure called the cell plate forms along the equator of the cell to divide it into two new daughter cells.

Without cytokinesis, cells would contain multiple nuclei and could not function properly.

Interphase

Interphase is a vital part of the cell cycle that occurs before mitosis. It is the phase where the cell prepares for division by growing and replicating its DNA. This phase is not part of mitosis itself but is crucial for successful cell division.
During interphase, several key events take place:

• G1 Phase: The cell grows and performs its normal functions. It also synthesizes proteins and organelles in preparation for DNA replication.
• S Phase: The cell replicates its DNA, ensuring that each daughter cell will have a complete set of chromosomes.
• G2 Phase: The cell continues to grow and prepares all necessary components to enter mitosis.

Interphase ensures that the cell is ready to successfully divide into two daughter cells during mitosis.

Cell Cycle

The cell cycle is the series of stages that a cell goes through to grow and divide. It consists of interphase and mitosis along with cytokinesis.
Understanding the cell cycle is essential to comprehend how cells reproduce and maintain life. The main components of the cell cycle are as follows:

• Interphase: The longest phase, where the cell grows and prepares for division through G1, S, and G2 phases.
• Mitosis: The process where the cell's nucleus divides into two, followed by cytokinesis.
• Cytokinesis: The final step, where the cell's cytoplasm divides, creating two daughter cells.

The proper progression through these phases ensures that cells divide accurately and maintain the correct chromosome number.

Chromosome Alignment

Chromosome alignment is a critical step in mitosis, specifically occurring during metaphase. During this phase, chromosomes line up at the cell's equator, preparing them for separation.
Here’s what happens during chromosome alignment:

• Chromosomes condense and become visible as distinct entities.
• The nuclear envelope dissolves, allowing the spindle fibers to attach to the chromosomes’ centromeres.
• Spindle fibers pull aligned chromosomes to the center of the cell, ensuring they are evenly distributed for the upcoming separation.

This alignment is vital for ensuring that when chromosomes are separated, each new cell will receive an accurate copy of the genetic material. Errors in alignment can lead to uneven distribution of chromosomes and genetic disorders.