What do cells spend their time doing? Why do they do this? N-6 Cell Division What do cells spend their time doing? Why do they do this?

Cell Cycle: The regular sequence of growth and division that happens in cells

Stage 1: Interphase During interphase, the cell grows to its mature size, makes a copy of its DNA, and prepares to divide into two cells Growth – during the first part of interphase, the cell doubles in size DNA Replication – the cell makes a copy of its DNA in the nucleus. This means that there are TWO copies of the DNA (instructions) in each nucleus Cells spend 90% of their lives in this stage

Stage 2: Mitosis During mitosis, one copy of the DNA is distributed into each of the two ‘daughter’ cells. This is divided into four parts: Prophase Metaphase Anaphase Telophase

Chromosomes: (humans have 23 pairs) DNA Centromere Two Chromatids

Mitosis - Prophase Chromosomes are visible

Mitosis - Metaphase Chromosomes line up in center of the cell

Mitosis - Anaphase Chromatids are pulled to opposite ends of the cell

Mitosis - Telophase New nuclear membranes form around each new set of chromosomes

Stage 3: Cytokinesis The cell membrane ‘pinches’ together in the middle of the cell forming two ‘daughter’ cells. Cytoplasm divides, distributing the organelles into each of the new cells.

Can we identify the following? Prophase Metaphase Cytokinesis Telophase Anaphase Ana or Telo? Interphase 10

DNA Replication DNA Replication ensures that each daughter cell will have all of the genetic information it needs to carry out its activities. There are four pieces of the puzzle: Adenine and Thymine Cytosine and Guanine The order that these ‘pieces’ fit together determine our genetics! Animation