Modern Cloning Techniques | Genetics | Biology | AddyESchool

CREDITS Animation & Design: Jean-Pierre Louw (www.behacne.net/Appel718) Narration: Dale Bennett Script: Gemma Young When we talk about clones in science we mean organisms that are identical copies - they have the same DNA as each other. Identical twins are examples of naturally occurring clones. Both plants and animals can be cloned. Let’s start with plants. A gardener, farmer or plant breeder might want to make many copies of a particular plant quickly. The easiest, and cheapest, way to do this is to take cuttings. Shoots are cut from the parent plant. Then the end of each shoot is dipped in hormone rooting powder and placed into a pot of soil. The hormone rooting powder will encourage the cutting to start growing roots, and soon a whole new plant will have grown which is identical to the original plant. This method works because the shoots of plants contain stem cells , which are able to differentiate to form different cells and tissues. You can find out more about this process by watching this video... However, you might want to produce hundreds of plants from only a small piece of plant tissue. To do this another method called tissue culture, also known as micropropagation, is used. Here, a few cells are taken from the parent plant and placed onto a nutrient jelly using aseptic technique (this means making sure no microorganisms contaminate the jelly). The cells will start to differentiate and form new plants. Animals can also be cloned but different techniques need to be used. In animals only embryo stem cells have the ability to differentiate into all the different types of cells found in an adult. There are two methods you can use. The first is called embryo cloning. A farmer might have a cow that gives a lot of milk and wants to use her to create many calves. The cow is artificially inseminated using the sperm of a bull. The embryos grow until they form a ball of embryonic stem cells. Before they become specialised, the embryos are removed from the uterus, divided up into separate embryos, which will all have the same DNA, and then each is placed into the womb of a different cow. These cows are surrogate cows . They are just being used to grow the embryos until they are born. The calves born will be clones of each other, but not a clone of the mother due to the bull’s sperm. Hopefully, the calves will have the characteristics that the farmer desires... But as sexual reproduction is involved, and the genes from both parents are randomly mixed, there is always the chance that they won’t There is a way to get around that problem... and that is to use another technique called adult cell cloning . This is used to form a clone of an adult animal. You might have heard of Dolly the sheep - she was the first mammal to be cloned back in 1996. There are several steps to this process: ■ An unfertilised egg cell is taken from an adult female, and the nucleus is removed. ■ A body cell, such as a skin cell, is taken from a different adult. ■ The nucleus is removed from this adult body cell and is inserted into the egg cell. ■ An electric shock stimulates the egg cell to divide to form an embryo. ■ These embryo cells contain the same genetic information as the adult body cell. ■ When the embryo has developed into a ball of cells, it is inserted into the womb of an adult female surrogate to continue its development. ■ So 3 different adults are used! --------------------------------------- Video Credit https://youtu.be/FjBgLIE7514