This practical involves a very simple cloning technique which is commonplace in greenhouses and gardens across the world. The process involves taking a small cutting from a plant and letting it grow into a plant itself. After a period of growth, both plants are observed to be genetically identical.
Equipment typically required (per set):
- Small geranium plant in pot
- Small pot
- Rooting powder
- Tile or chopping board
- Plastic food bag
Geraniums work very well for this practical as they are quite hardy. They also are of a manageable size and are fairly fast growers. They also grow well in a science preproom!
A small stem without flowers should be carefully cut from the plant. The stem needs to be between 5 and 10cm long ideally. All the leaves should be removed from the stem apart from the top few. The stem should be cut at an angle so that the end of the stem resembles a sharp wedge. This end should be dipped into the rooting powder (make sure you follow the instructions on the packet carefully).
The small pot should be filled with compost and packed down slightly. The powdered end of the stem should be inserted into the compost and water added so that the compost is moist (not wet). The whole thing should be put inside a transparent plastic bag.
The cutting should be kept moist and the bag can usually be removed after a few days.
After a few weeks, the cutting should have developed into a small plant. Students may want to observe the similarities and differences between the cutting and the original plant. It should be noted that some of the features of plants are genetically controlled and some are influenced by the environment in which the plant is located. The size and shape of leaf, the colour and the shape of the flower are genetic characteristics whereas the size of the plant and the amount of flowers and leaves are environmental characteristics. Students should see that the genetic features of the two plants are very similar or identical.