Available online
Description
This programme examines the way in which the reproductive mechanisms of different species adopt different forms, or breeding systems, according to their way of life and the environment. Most of the... examples shown are from an English woodland in early spring.
This programme examines the way in which the reproductive mechanisms of different species adopt different forms, or breeding systems, according to their way of life and the environment. Most of the... examples shown are from an English woodland in early spring.
| Module code and title: | S364, Evolution |
|---|---|
| Item code: | S364; 12 |
| First transmission date: | 09-01-1981 |
| Published: | 1981 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:28 |
| + Show more... | |
| Producer: | P. L Firstbrook |
| Contributor: | Jonathan W. Silvertown |
| Publisher: | BBC Open University |
| Keyword(s): | Breeding systems; Evolution; Pollination; Reproductive mechanism; Wytham Wood |
| Footage description: | Shots of salmon breeding, of dandelion seeds, of hummingbird, of birds eating berries, of butterflies and of a bird feeding its chicks. Commentary introduces the programme. Commentary briefly describes sexual reproduction and its most important consequence from a genetic point of view. Shots of wolves and ostrich copulating, of paramecium mating and of bees pollinating flowers. Over shots of great tits and their young in Wytham Wood, Oxford and of worms mating, commentary introduces the concept of outcrossing. Jonathan Silvertown, in Wytham Wood, examines the reproductive organs of several plant species, some hermaphrodite and others dioecious. He looks at bluebell, arum and dogs mercury. Silvertown then looks at some examples of monoecy in which flowers of both sexes are found on the same plant. Shots of birch catkins and of an ash. The programme, over shots of bluebells, briefly explains what is meant by 'selfing' and goes on to examine how some plants prevent their own ovules from being self-fertilised. Shots of wild flowers and an animated diagram. Silvertown explains why such complex systems to prevent inbreeding have evolved. Shots of brussel sprout plants, of great tits and of a forsythia plant. He goes on to look at a primrose, a plant which has evolved a system used by a wide variety of hermaphrodite plants to ensure outcrossing. Silvertown goes on to point out the advantages of hermaphrodite individuals who self fertilise under certain conditions. Using shots of primrose, an animated map showing primrose distribution and cross sections of a primrose flower, he explains that the environment plays a large part in determining which system of reproduction a plant adopts. Finally the programme examines some plants which normally outcross but which will self fertilise in certain concitions. Shots of groundsel, orchid, stitchwort, bluebells and thistle. Shots of a moorhen and her chicks end the programme. |
| Master spool number: | HOU3822 |
| Production number: | FOUS205Y |
| Videofinder number: | 2063 |
| Available to public: | no |
