Biotechnology

Biotechnology is the use of technology to change the genetic makeup of living things for human purposes. Generally, the purpose of biotechnology is to create organisms that are useful to humans or to cure genetic disorders. For example, biotechnology may be used to create crops that resist insect pests or yield more food, or to create new treatments for human diseases.


GENE CLONING
Gene cloning is the process of isolating and making copies of a gene. This is useful for many purposes. For example, gene cloning might be used to isolate and make copies of a normal gene for gene therapy. Gene cloning involves four steps: isolation, ligation, transformation, and selection. You can watch an interactive animation about gene cloning at this link:


  1. In isolation, an enzyme (called a restriction enzyme) is used to break DNA at a specific base sequence. This is done to isolate a gene.
  2. During ligation, the enzyme DNA ligase combines the isolated gene with plasmid DNA from bacteria. (A plasmid is circular DNA that is not part of a chromosome and can replicate independently.) Ligation is illustrated in Figure below. The DNA that results is called recombinant DNA.
  3. In transformation, the recombinant DNA is inserted into a living cell, usually a bacterial cell. Changing an organism in this way is also called genetic engineering.
  4. Selection involves growing transformed bacteria to make sure they have the recombinant DNA. This is a necessary step because transformation is not always successful. Only bacteria that contain the recombinant DNA are selected for further use.

Cloning

Cloning is the process of creating an exact replica of an organism. The clone’s DNA is exactly the same as the parent’s DNA. Bacteria and plants have long been able to clone themselves through asexual reproduction. In animals, however, cloning does not happen naturally. In 1997, that all changed when a sheep named Dolly was the first mammal ever to be successfully cloned. Other animals can now also be cloned in a laboratory.

The process of producing an animal like Dolly starts with a single cell from the animal that is going to be cloned. Below are the steps involved in the process of cloning:

  1. In the case of Dolly, cells from the mammary glands were taken from the adult that was to be cloned. But other somatic cells can be used. Somatic cells come from the body and are not gametes like sperm or egg.
  2. The nucleus is removed from this cell.
  3. The nucleus is placed in a donor egg that has had its nucleus removed.
  4. The new cell is stimulated with an electric shock and embryo development begins, as if it were a normal zygote.
  5. The resulting embryo is implanted into a mother sheep, where it continue its development


IS CLONING EASY?
Cloning is not always successful. Most of the time, this cloning process does not result in a healthy adult animal. The process has to be repeated many times until it works. In fact, 277 tries were needed to produce Dolly. This high failure rate is one reason that human cloning is banned in the United States. In order to produce a cloned human, many attempts would result in the surrogate mothers experiencing miscarriages, stillbirths, or deformities in the infant. There are also many additional ethical considerations related to human cloning.

Biotechnology

Files:

Biotech Cheat Sheet
File Size: 218 kb
File Type: pdf
Download File
Genetics review
File Size: 510 kb
File Type: pdf
Download File
practice files will be updated shortly 

Helpful links

Vocabulary

  • cloning: Process of creating an exact replica of an organism.
  • somatic cell: Cell that comes from the body and is not a gamete cell like a sperm or egg.
  • zygote: Cell that forms when a sperm and egg unite; the first cell of a new organism.

Gel Electrophoresis