Skip to 0 minutes and 5 seconds SPEAKER 1: We use cauliflower because it’s comprised mostly of actively dividing cells and it’s readily available. It’s also quite a tough vegetable and can withstand some rough handling. The process itself is quite straightforward. You take a floret, break off a smaller bit, and then using a scalpel we’re going to cut off a microfloret or an explant.
Skip to 0 minutes and 46 seconds So that’s my explant, and it’s ready to clone. The next step is to disinfect it. And for that, I use a sterilising solution. It’s why I’m wearing the gloves, so I don’t splash any.
Skip to 1 minute and 1 second And it’s very simple. I just drop my explant into the solution and give it a good swirl for about five seconds.
Skip to 1 minute and 13 seconds And I’m going to leave that there for 15 minutes, giving it another swirl every two or three minutes. At the same time, I need to put these forceps into a beaker of the same sterilising solution. The key to the success of this technique is this stuff. It’s an agar growth medium that was developed for use in conservation work. It’s already being used to save endangered species. Once the 15 minutes are up, you take the explant and put it into this medium.
Skip to 2 minutes and 6 seconds So that’s now ready. Your students can put their name and the date on it. And just leave it by a sunny window for about three weeks. And after that, they’ll have their very own cauliflower clone.
Skip to 2 minutes and 32 seconds SPEAKER 2: It surprised me how precise you’ve got to be with some of this stuff, how important it is to sterilise things and not to contaminate them for then how that could affect your end result.
Skip to 2 minutes and 46 seconds SPEAKER 3: It looks really basic, but it’s really interesting.
Skip to 2 minutes and 49 seconds SPEAKER 4: I think it’s really interesting, mainly because it’s what professionals do.
Skip to 2 minutes and 58 seconds SPEAKER 1: With this practical, you can bring current techniques from the world of research and conservation into your school. Your students can use the techniques for themselves, and they’ll find a real sense of ownership of the cauliflower they’ve cloned.
Skip to 3 minutes and 11 seconds SPEAKER 5: The agar jelly was more solid than I’d expected, so I found it a little bit difficult to push in the microfloret. But other than that, it was fine.
Skip to 3 minutes and 28 seconds SPEAKER 1: The practical itself doesn’t take very long to do. But it’s a powerful way to complement the teaching of the theory around cloning. It can be used to demonstrate asexual reproduction and mitotic cell division. It’s also a compelling demonstration of totipotency– that is that almost any cell in a plant can be used to produce a new plant.
This practical provides first-hand experience of plant tissue culture, a technique that is widely used in conservation biology, in horticulture for the inexpensive propagation of many clones of a particular plant and in gene technology for the cultivation of genetically modified cells into complete plants.
This can also be used to bring ethical, legal, and social dimensions into this section of the curriculum.
Micropropagation is the regeneration of whole plants from small pieces of plant material. These small pieces (known as ‘explants’) are grown on sterile media and the plants produced can be potted up in soil and transferred to the glasshouse/field. Various parts of a plant can be cultured; plants have been regenerated from leaves, stems, roots, meristems, flowers and even pollen or ovules. In this case, students use a tiny piece of a cauliflower. Since all the explants come from the same cauliflower, the new plants will be clones of each other.
Add in these new concepts to your map and consider how you will integrate ethical, legal and social dimensions.
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