Y8 2.3 Mitosis

The Process of Mitosis

Also known as cell division

Theory

Practice

What is Mitosis?

• Mitosis is the process where a single cell divides into two identical daughter cells.
• It ensures that each new cell receives a complete set of chromosomes.

Why do you think it's important for the daughter cells to be identical?

The Cell Cycle

• The cell cycle is a series of events that take place in a cell leading to its division and duplication.
• Mitosis is the part of the cell cycle when the cell divides.

Interphase

Inbetween two mitosis is the INTERPHASE. That phase allows the cell to grow, produce molecules for the body, such as proteins, and prepare for division by making a copy of their DNA.

The Phases of Mitosis

Mitosis is divided into four main phases:Prophase Metaphase Anaphase Telophase

• Chromosomes become visible and the nuclear envelope breaks down.
• Spindle fibers begin to form.

• Chromosomes line up in the middle of the cell.
• Each chromosome is connected to spindle fibers.

• Sister chromatids (= 1 copy of each chromosome) are pulled apart to opposite ends of the cell.
• This ensures each new cell will have the same number of chromosomes.

• Chromatids reach the opposite poles of the cell.
• New nuclear membranes start to form around each set of chromosomes.
• A cleavage furrow starts to pinch the cell.

Cytokinesis: The Final Split

The cell membrane pinches in and eventually divides into two daughter cells.

That's what it looks like under a microscope:

Practice!

Practice!

Practice!

Let's check what you remember

Mitosis in Action: Growth and Repair

• Mitosis allows organisms to grow, replace damaged cells, and reproduce asexually.

• Can you think of an example where mitosis is used for repair in the body?

Let's observe mitosis under a microscope!