Learn: Mitosis & The Cell Cycle

Welcome!You've already learned about chromosomes and cell differentiation, which are key to understanding how cells divide and specialise. Today, we'll focus on mitosis and the cell cycle, building on your knowledge of cell structure and function.

What is Mitosis?Mitosis is a type of cell division that produces two identical daughter cells. It is essential for growth, repair, and asexual reproduction in organisms. This process ensures that each new cell has the same genetic material as the original cell.

The Cell CycleThe cell cycle is the sequence of events that cells go through to grow and divide. It consists of three main stages: interphase (growth and DNA replication), mitosis (division of the nucleus), and cytokinesis (division of the cytoplasm).

Stages of MitosisMitosis has four main stages: prophase, metaphase, anaphase, and telophase. These stages occur after DNA replication in interphase.

ProphaseIn prophase, chromosomes condense and become visible. The nuclear envelope breaks down, and spindle fibres start to form. This prepares the cell for dividing its genetic material.

MetaphaseDuring metaphase, chromosomes line up along the centre of the cell (the equator). Spindle fibres attach to the centromeres of the chromosomes to ensure they are pulled apart accurately.

AnaphaseIn anaphase, the chromatids (copies of chromosomes) are pulled apart by spindle fibres and move to opposite ends of the cell. This ensures each new cell will have an identical set of chromosomes.

TelophaseDuring telophase, nuclear envelopes reform around each set of chromosomes at opposite ends of the cell. The chromosomes start to uncoil, and the cell is nearly ready to divide completely.

CytokinesisCytokinesis is the final stage of the cell cycle, where the cytoplasm divides to form two separate cells. In animal cells, a cleavage furrow forms, while in plant cells, a cell plate develops to separate the daughter cells.

Review Time!Great work! You've learned about mitosis, the cell cycle, and its importance for growth and repair. Now let's test your understanding with a few questions.