Plant vs Animal Cytokinesis
Cell cycle involves events that occur from one cell division to the next cell division. This mainly involves in cell growth and cell division. Prokaryotic cell cycle involves 3 stages. Cell growth is the first step, where the cell doubles in its size. Nuclear division is the next step, where the nuclear material divides in to two by simple division. The final step is cell division, where the cytoplasm divides and two daughter cells are formed. The eukaryotic cell cycle has 5 phases. G1, S, G2, M and C. The first three phases G1, S, and G2 are called interphases. Cell growth and synthesis of cellular materials take place during interphase. M involves nuclear division and C involves cell cytokinensis. Cytokinesisis is the process by which the cytoplasm of a single eukaryotic cell is divided into two in order to form two daughter cells. Usually, during the late stages of mitosis, it is being initiated. A dividing structure known as the cell plate is formed in plant cells. This is formed across the centre of the cytoplasm. Finally, a new cell wall is formed between the two daughter cells.
What is Animal Cell Cytokinesis?
Sister chromatid separation takes place in the anaphase of mitosis. In the animal cell, cytokinensis begins shortly after that. A contractile ring and actin filaments assembles in the equator of the cell. The contractile ring is made up of non-muscle myosin II. Myosin II move along these actin filaments using the free energy released when ATP is hydrolyzed. Then the cell membrane constricts and forms a cleavage furrow. Due to continuous hydrolysis, this cleavage moves inwards. This is a striking process, which is even visible through a light microscope. Ingression continues until the cell physically divides into two. Abscission provides a structural basis to ensure the completion of cytokinesis.
What is Plant Cell Cytokinesis?
Cytokinesis in plant cells is different from that in animal cells. This is due to the presence of the cell wall. In the plant cells, a cell plate is formed in the middle of the cell. They do not form a contractile ring. Several stages are involved in cell plate formation. Those are creating a phragmoplast, which is an array of microtubules, trafficking of vesicles to the division plane, fusing those to generate a tubular-vesicular network, continuing fusion of membrane tubules and their transformation into membrane sheets and deposition of cellulose, recycling of excess membrane and other material from the cell plate, and finally fusing it with the parental cell wall.
What is the difference between Plant and Animal Cell Cytokinesis?
• In plant cells, a contractile ring is not formed and instead a cell plate is formed at the centre of the cell. This is because the plant cell has a cell wall. In plant cells, cell plate begins to grow and elongate at the centre of the cell. During this, each end grows toward the opposite cell walls. This linear wall continues to grow to the inside of the cell. This is continued until it reaches the actual cell walls.
• In Animal cells, cell membranes on the opposite sides of the cell are pinched. It allows the cell to divide. Furrowing continues until the two sides are touching. When touched two new cells are separated. Cell wall is the structure which makes it impossible for the plant cell to pinch in.