Polymerase Chain Reaction (PCR) & Gene Editing

Another technology involves creating _____ copies _____ of DNA. This process is called Polymerase Chain Reaction (PCR) and it can be used to copy an entire copy of DNA or just individual segments.

This process can produce an unlimited _____ quantity _____ of DNA and can make it easier for scientists to _____ study _____ the DNA.

The process involves a device called a _____ thermalcycler _____. This device repeatedly _____ heats _____ and then cools the DNA.

The heating part causes the DNA to _____ unzip or separate _____ and the cooling process enables it to reform. Specific DNA primers and a special type of DNA Polymerase are also added to the sample.

Regular DNA Polymerase cannot be used as the heating process would destroy it. Instead, something called _____ taq polymerase _____ is used. This enzyme was found in _____ thermophillic _____ bacteria that can withstand the high temperatures.

Another category of DNA technology is _____ gene editing _____. This involves either modifying an existing _____ gene _____ or removing a gene and then replacing it with a different gene.

The genes are removed using a special type of _____ restriction _____ enzyme. These special restriction enzymes are created using a process known as _____ CRISPR _____, which stands for Clustered Regularly Interspaced Short Palindromic Repeats.

When _____ genes _____ are removed from one organism and added to the DNA of another organism, the second organism will express the traits of the first. This is called _____ recombinant _____ DNA Technology.

The organisms result from this are called genetically modified organisms or simply _____ transgenic _____ organisms. Some examples include: bacteria that produce mammalian _____ hormones _____, rice that produce _____ vitamin A _____, and crops that are _____ herbicide _____ resistant.

The last bit of technology deals with cloning. A clone is a member of a population of genetically identical cells produced from a single _____ cell _____. This process is easy to perform with _____ unicellular _____ organisms, but has not been perfected with _____ multicellular _____ organisms.

The first mammal produced by cloning was created in 1997 by Ian Wilmut. He took a cell from the _____ udder _____ of a sheep and an egg cell from another sheep. The _____ nucleus _____ was removed from the egg. The cell taken from the udder was then _____ fused _____ with the hollow egg.

After applying an _____ electric shock _____, the cell began to divide. This dividing _____ cell _____ was then placed into a foster mother where it developed into a lamb which they called _____ Dolly _____. She was the only one out of _____ 277 _____ trials to survive.

Cloning may be used to preserve _____ endangered species _____, to improve _____ agriculture _____ and to advance medical technology.

Some scientists are even looking at cloning _____ organs _____. The major concerns center around the possibility of _____ human _____ cloning.