Chromosomes and cell division

To describe the structure of chromosomes and their location within the cell.
To outline the main stages of the cell cycle, including DNA replication and mitosis.
To explain the importance of mitosis for growth, development, repair, and asexual reproduction.

The nucleus of a cell contains chromosomes.
Chromosomes are made up of tightly wound DNA molecules.
Each chromosome carries many genes, which are small sections of DNA containing instructions for making specific proteins.
In most body cells, chromosomes are found in pairs.

How DNA is wound up up into chromosomes

The process of cell divison by mitosis

There are two forms of cell division: mitosis and meiosis.
- Mitosis is essential for the growth and development of multicellular organisms, as well as for tissue repair and asexual reproduction.
- Meiosis is the form of cell division used to produce gametes for sexual reproduction. Meiosis is discussed in deteil in Topic 6.

Nucleus: The organelle in eukaryotic cells containing chromosomes.
Chromosomes: Structures made of tightly wound DNA found in the nucleus, carrying genes.
Genes: Small sections of DNA that contain instructions for making specific proteins.
Cell cycle: The series of stages a cell goes through as it grows and divides.
DNA Replication: The process where the cell makes an identical copy of its DNA before division.
Mitosis: A type of cell division that produces two genetically identical daughter cells.
Cytoplasm: The material or protoplasm within a living cell, excluding the nucleus.
Cell membrane: The partially permeable boundary surrounding the cytoplasm of a cell.

Cell Cycle Diagram: Draw and label the stages of the cell cycle (Growth, DNA Replication, Mitosis) using simple diagrams to show what happens to the chromosomes at each stage.
Mitosis Model: Use different coloured string or pipe cleaners to represent chromosomes and model the process of mitosis step-by-step on a table or floor.