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Programme examines the mechanism for movement of chromosomes during mitosis.
Metadata describing this Open University video programme
Module code and title: S321, Physiology of cells and organisms
Item code: S321; 07
First transmission date: 12-05-1974
Published: 1974
Rights Statement:
Restrictions on use:
Duration: 00:23:20
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Producer: John Groom
Contributor: Norman Cohen
Publisher: BBC Open University
Keyword(s): Cell division; Chromosome movement; Polarised light microscopy
Footage description: Film shots of a chromosome being stretched with a very fine microneedle. (Film shots by Dr.R.B. Nicklas). Norman Cohen discusses the probability of chromosomes being attached to the cell structure in some way during mitosis and miosis (Above film suggests that this is so) Film sequence shows mitosis in the cells of an African blood lily. Commentary by Cohen. Commentary by Cohen continues during short break in the film. The Film showing mitosis in the blood lily continues. Film shots of the mitosis process shown again from beginning. Cohen continues his discussion on the probability of the existence of cell structures (spindles) to which chromosomes are attached during mitosis and miosis. Shots of a series of drawings by the early microscopist Theodore Boveri showing mitosi The drawings date frorm 1887 and show spindles present in the cells. Cohen lists some of the questions researchers will have to answer to determine the full role of spindles on the cell during mitosis and miosis. Cohen explains how spindles can be isolated. for study. He discusses the experiment on sea urchin eggs by Mazia and Dan in the 1950s. Shot of spindles and attached chromosomes in isolation. Egg material has been dissolved to expose the spindles. Cohen discusses again the film by Nicklas on chromosome stretching. He explains the experimental techniques and describes the lab. apparatus required. Shots of a micromanipulator. Shots of the Nicklas film again. Commentary by Cohen. The chromosome is stretched and then released. It springs back to its original position. Cohen asks questions which the researcher would need to examine in a study of chromosome movement in the cell during mitosis. Cohen begins a discussion on methods of gathering evidence to answer these questions. He lists some the hypotheses for chromosome movement put forward in the past. Shots of diagrams accompany each. Cohen examines chromosome attachment to spindle He explains the techniques of polarised light microscopy which allows the researcher to see spindles in the living cell. This process was developed by Prof. Shinya Inoue. Polarised light shots of cells showing spindles Further film shots of cells during mitosis using polarised light microscopy. Commentary by Cohen. Cohen examines the roles of the two types of birefringence material in the mitosis process. He uses a large mag. board diagram of a cell as an aid. Cohen discusses mainly Inoue's work in this field. Film shots of Inoue and Bajer show the birefringence and chromosomal tufts during anaphase. Cohen continues his discussion. He speculates now on the nature of the actual mechanism for chromosomal movement. Cohen uses a hypothetical model of birefringence and tufts as aids.
Master spool number: 6HT/71272
Production number: 00525_1111
Videofinder number: 1824
Available to public: no