Description: Segment 1 Opening credits. Dr Austin Crathorn gives a general introduction of cell replication, narrating over films of cells growing and dividing, and discussing the cells' developments in detail. He also talks about the cells' DNA, displayed in diagrams, and about cell survival after doses of radiation. He shows a Petri dish of cell colonies made by cells that survived a dose of x-rays. He then introduces Dr Revell. Time start: 00:00:00:00 Time end: 00:07:31:19 Length: 00:07:31:19 Segment 2 Dr Revell talks about the effects of radiation on cells at the cellular and chromosomal level, showing photomicrographs of hamster cells one received no radiation dose and the other has been damaged by radiation. Revell discusses the chromosome damage then goes on to talk about how radiation affects cell division. He also talks about the affect of x-rays on cell colony growth, using photomicrographs to illustrate his points. Time start: 00:07:31:19 Time end: 00:15:53:02 Length: 00:08:21:08 Segment 3 Dr Roberts begins his section of the lecture on how the damaged call overcomes damage to its DNA. He refers to diagrams and photographs throughout his talk. He discusses excision repair and post-replication repair. Time start: 00:15:53:02 Time end: 00:23:38:19 Length: 00:07:45:17 Segment 4 Dr Steel introduces his part of the lecture on cell population kinetics and tumour growth. He considers the proliferation of cells in vivo and its relationship to therapeutic response. First he summarises information about the kinetic state of cells in tumours and in normal tissues. Time start: 00:23:38:19 Time end: 00:28:50:18 Length: 00:05:11:24 Segment 6 Steel continues his section and talks about using assays for tumour stem cells to test the behaviour of cancer cells. He discusses two charts showing the affects of radiation on cells. He concludes the lecture. End credtis. Time start: 00:35:57:10 Time end: 00:41:10:06 Length: 00:05:12:21