Cloning

Cuttings and Tissue Culture

Plants can be cloned in 2 ways:

1. Cuttings from parent plants can be used to make genetically identical copies of the parent plant. This method is quick and simple and has been used by gardeners for many years.

2. Tissue culture (micropropagation) is slightly more complex as whole genetically identical plants are grown from a small sections of plants called explants. Explants are extracted from a plant, put in agar growth medium with plant hormones to make them grow before being transferred into soil to fully develop. This process produces lots of plants quickly and it enables plants to be grown all year round but the process is a lot more complicated. Tissue culture is often used to preserve rare plant species or grow lots of plants in nurseries. 

Embryo Transplants and Adult Cell Cloning

Animals can be cloned in 2 ways:

1. Embryo cloning produces cloned offspring and is often used by farmers. They will artificially fertilise an egg from their best female animal with a sperm cell from their best male animal.  Before the cells start to specialise, the embryo is split into several clones. The cloned embryos continue developing and get implanted into host mothers. Lots of genetically identical animals with desired characteristics from the original parents will be formed. 

2. Adult cell cloning creates a genetically identical clone of an existing animal, the most famous example being Dolly the sheep. First, the nucleus of an unfertilised egg cell is removed. Then the nucleus of a adult body cell (from the animal you want to clone) is removed and inserted into the empty egg cell. The cell then receives an electric shock which stimulates it to divide into an embryo. The embryo is implanted into a host mother to continue its development into a clone of the original adult. 

Issues with Cloning

Cloning is very useful for preserving endangered species, understanding the mechanisms of ageing and the rapid production of high quality food. However, it has many issues:

• It reduces the gene pool in populations making them more likely to be wiped out by a new disease. 
• Clones may not be as healthy as the original organism. 
• There is potential for human cloning but attempts will likely be unsuccessful and there are several laws in place to prevent it from happening.
• Some people believe cloning is interfering too much into the creation of new life.