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Description
This programme illustrates sections of the text of Unit 7 and is mainly concerned with experimentation in plants. The speakers are Dr. Heather Adamson and Dr. Don Adamson, Visiting Lecturers in bi...ology at the Open University. Some of the classical plant growth experiments on coleoptiles described in the unit are illustrated with time lapse film. These include the growth of shoots towards the light, and the collection of auxin in agar blocks and the use of the collected auxin to promote growth. A sensitive method for recording changes in the length of coleoptiles over intervals of a few minutes is demonstrated and some of the limitations of the method discussed. In the remaining part of the programme the results of some extremely simple experiments on plant growth are analysed in order to make important points about conducting experiments. The nature of the variability of the growth response of coleoptile segments to auxin is discussed and the sequential response of the cells of pea seedling segments to different growth substances is analysed.
This programme illustrates sections of the text of Unit 7 and is mainly concerned with experimentation in plants. The speakers are Dr. Heather Adamson and Dr. Don Adamson, Visiting Lecturers in bi...ology at the Open University. Some of the classical plant growth experiments on coleoptiles described in the unit are illustrated with time lapse film. These include the growth of shoots towards the light, and the collection of auxin in agar blocks and the use of the collected auxin to promote growth. A sensitive method for recording changes in the length of coleoptiles over intervals of a few minutes is demonstrated and some of the limitations of the method discussed. In the remaining part of the programme the results of some extremely simple experiments on plant growth are analysed in order to make important points about conducting experiments. The nature of the variability of the growth response of coleoptile segments to auxin is discussed and the sequential response of the cells of pea seedling segments to different growth substances is analysed.
| Item code: | S22-; 07 |
|---|---|
| Series: | Comparative physiology |
| Episode | 7 |
| First transmission date: | 22-04-1972 |
| Published: | 1972 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:22:15 |
| + Show more... | |
| Producer: | Tony Laryea |
| Contributors: | Don Adamson; Heather Adamson |
| Publisher: | BBC Open University |
| Keyword(s): | Agar blocks; Auxin; Coleoptiles; Experiments; Growth of shoots; Plants; Recording changes |
| Footage description: | Heather Adamson introduces the programme. She provides the commentary for the time lapse film of experiments showing the growth response of coleoptiles to auxins. Growth of coleoptiles is shown when illuminated from above and from the side to illustrate phototropism. Several classical experiments based on phototropism are shown. The collection of auxin in agar blocks and its use to promote growth is demonstrated. Don Adamson explains the need for measuring plant growth over short periods of time (minutes rather than days as in time lapse photography). He demonstrates a sensitive method of measuring growth in coleoptiles within 10 to 15 minutes of treatment with auxin. Heather shows several samples of coleoptiles to illustrate the problem of variability in experiments dealing with growth and discusses ways of dealing with it. Time lapse shots of coleoptiles show some of the variability in growth. Heather Adamson continues Don Adamson examines the need for careful selection, particularly in more complex organs, for growth experiments. He illustrates this point by examining the growth of segments cut from the stem of pea seedlings grown in the dark. The growth of these segments in gibberellin and auxin solutions illustrates the sequential response of cells to different growth substances. Don Adamson discusses the possible reasons for the two distinct responses shown by the plant segments in the experiment above. He asks students to think about the experimental techniques used as a possible cause of the variation. Adamson suggests that the unresponsive segments failed to grow because of an oxygen shortage due to damage to the segments during the experiment. |
| Master spool number: | 6LT/70458 |
| Production number: | 00521_2125 |
| Videofinder number: | 3581 |
| Available to public: | no |
