Mitosis

What phase becomes before mitosis?

Interphase, which is divided into stages called gap phase 1, synthesis and gap phase 2.

What is interphase?

A period of cell growth and DNA replication, gap phase 1 is where cell grows and new organelles/proteins are made. Synthesis is where cell replicates its DNA, ready to divide by mitosis. Gap phase 2 is where cell keeps growing and proteins needed for cell division are made.

What are the division stages of mitosis?

Prophase, metaphase, anaphase and telophase.

What is prophase?

Chromosomes condense, they get shorter and fatter. Tiny bundles of proteins called centrioles start moving to opposite ends of the cell, forming a network of protein fibres across it called the spindle. Nuclear envelope breaks down and chromosomes lie free in cytoplasm.

What is metaphase?

The chromosomes line up along the middle of the cell and become attached to the spindle by their centromere.

What is anaphase?

The centromeres divide which separates each pair or sister chromatids. The spindles contract, pulling chromatids to opposite poles of the spindle, centromere first. This makes the chromatids appear v-shaped.

What is telophase?

Chromatids reach the opposite poles on spindle. They uncoil and become long and thin again, now called chromosomes. Nuclear envelope forms around each group of chromosomes, so now 2 nuclei. Division of the cytoplasm(cytokinesis, starts in anaphase) finishes in telophase. Now there are 2 daughter cells that are genetically identical to the original. The cycle is then repeated starting with interphase again.

What is cytokinesis?

The physical process of cell division, divides cytoplasm.

When does cell division usually stop?

It usually stops when there’s enough new cells.

What happens if cells keep dividing?

It makes more and more cells, which forms a tumour - cancer.

Root tip practical.