Question

The main difference between dividing an animal and plant cell lies in (a) Cell plate formation (b) Chromosome movement (c) Coiling of chromosome (d) Chromosome division

Short answer

The main difference lies in (a) Cell plate formation.

Step-by-step solution

Review the basics

First, it is necessary to be aware that both animal and plant cells undergo a process called 'mitosis' for cell division. This involves stages like prophase, metaphase, anaphase, telophase, and cytokinesis. In all these stages, characteristics (b), (c), and (d) i.e., Chromosome movement, Coiling of chromosome, and Chromosome division take place in both types of cells.

Identify the unique process

Then, you have to zero in on the process that is unique or different in one type of cell. The formation of the cell plate is a process exclusive to plant cells. This is due to the presence of a rigid cell wall. During cytokinesis in plant cells, a cell plate is formed along the centre of the cell which gradually develops into a cell wall, eventually dividing the cell into two.

Key concepts

Cytokinesis in Plant Cells

Cytokinesis is the final step of cell division where the cytoplasm of a parental cell is divided between two daughter cells. In plant cells, cytokinesis is a unique process compared to how it occurs in animal cells. This difference stems from the presence of a rigid cell wall in plants, which animal cells do not have.
During cytokinesis in plant cells, the formation of a structure called the "cell plate" occurs at the cell's midline. This is unlike animal cells, where a cleavage furrow forms to separate the cells.
Moreover, the cell plate grows outward until it fuses with the cell membrane, effectively partitioning the cytoplasm of the two new cells. The involvement of vesicles originating from the Golgi apparatus is crucial in this process, as they supply the necessary materials for forming the new cell wall.

• The cell wall in plants provides structural support and a defined shape.
• The rigidity of the cell wall presents a mechanical challenge compared to flexible animal cell membranes, necessitating the unique cytokinesis process.

This cytokinesis mechanism is pivotal for the correct separation and development of plant cells.

Mitosis Stages

Mitosis is a type of cell division crucial for growth, repair, and sometimes reproduction in living organisms. It consists of several stages to ensure each daughter cell receives an identical set of chromosomes. Understanding these stages helps comprehend how cells duplicate and function.
The mitosis process consists of several key stages:

• Prophase: Chromosomes condense and become visible under a microscope. The nuclear envelope begins to break down, and spindle fibers form.
• Metaphase: Chromosomes align in the middle of the cell, known as the equatorial plate, and spindle fibers attach to the centromeres.
• Anaphase: The sister chromatids are pulled apart toward the opposite poles of the cell by the shortening of spindle fibers.
• Telophase: The cell starts to return to interphase-like conditions, with the nuclear envelopes re-forming around each set of chromosomes at the poles. Chromosomes begin to de-condense.
• Cytokinesis: Although technically not a stage of mitosis, it often begins during telophase, leading to the complete separation of the two new cells.

Each stage ensures that the genetic material is accurately and efficiently divided between the daughter cells, maintaining genetic stability across cell generations.

Cell Plate Formation

Cell plate formation is a crucial part of cytokinesis in plant cells. The formation of the cell plate is distinctive due to plant cells' rigid and solid cell walls. This structure forms at the center line of the dividing cell, serving as a scaffold for building a new dividing wall between the daughter cells.
The process begins in the late stages of mitosis, typically during telophase. Vesicles derived from the Golgi apparatus are essential contributors, as they transport cell wall materials to the expanding cell plate. As these vesicles coalesce at the center of the cell, they form a growing disk of new cell wall material.
Once the cell plate is fully formed, it connects with the cell's existing plasma membrane, and the cell becomes split into two distinct, entirely new plant cells. This new wall is crucial for sustaining the plant’s internal structural integrity and segregating two living environments within the plant.

• The cell plate is the precursor to a new cell wall, providing a robust structural division.
• Through cell plate formation, plant cells protect themselves against environmental stressors that might damage more fragile structures.

This mechanism ensures that each daughter cell maintains the essential structures and functions, supporting the growth and development of the plant.