Cell Division and Differentiation

Define Chromosome

A mass of coiled threads of DNA and proteins. Chromosome is made of 2 sister chromatids connected by a centromere.

Why do chromosomes only become visible when the cell goes into mitosis?

Chromosomes are condensed by positively charged histones, which wrap around the DNA and produce dense clusters called nucleosomes.

What is the sequence of events that form the Cell cycle?

Interphase, Prophase, Metaphase, Anaphase, Telophase and cytokenesis.

What are the characteristics of Mitosis?

Mitosis consists of one nuclear division, to create 2 genetically identical daughter cells, each with 46 chromosomes and produces every cell in our body aside from the gametes.

When does Mitosis occur?

Mitosis has a role in growth and repair, asexual reproduction (produces identical daughter cells for genetically identical individuals) and sexual reproduction (after gametes have fused, mitosis to produce new cells and build up individual).

What are the benefits of super coiled DNA?

Some genes will not have genes available to be copied, and this will produce different types of cells.

Define Cell Cycle

The sequence of events by which a cell divides. Controlled by chemicals called Cyclins. The importance of cyclins, which regulate cyclin dependant kinases -checkpoints to ensure cells do not divide before DNA replication is finished (avoiding mutations and tumours).