• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

CLONING - Discusion

Extracts from this document...

Introduction

CLONING The possibility of human cloning, raised when Scottish scientists at Roslin Institute created the much-celebrated sheep "Dolly", created worldwide interest and concern because of its scientific and ethical implications. The feat, cited by Science magazine as the breakthrough of 1997, also generated uncertainty over the meaning of "cloning" a term traditionally used by scientists to describe different processes for duplicating biological material. When the media report on cloning in the news, they are usually talking about only one type called reproductive cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism. A basic understanding of the different types of cloning is important to taking an informed stance on current public policy issues and making the best possible personal decisions. The following three types of cloning technologies will be discussed: a) recombinant DNA technology or DNA cloning, b) ...read more.

Middle

coli cells. BACs utilize the naturally occurring F-factor plasmid found in E. coli to carry 100 to 300 kb DNA inserts. A YAC is a functional chromosome derived from yeast that can carry up to 1 MB of foreign DNA. Bacteria are most often used as the host cells for recombinant DNA molecules, but yeast and mammalian cells also are used. Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Dolly was created by reproductive cloning technology. In a process called "somatic cell nuclear transfer" (SCNT), scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth. ...read more.

Conclusion

Stem cells are extracted from the egg after it has divided for 5 days. The egg at this stage of development is called a blastocyst. The extraction process destroys the embryo, which raises a variety of ethical concerns. Many researchers hope that one day stem cells can be used to serve as replacement cells to treat heart disease, Alzheimer's, cancer, and other diseases. In November 2001, scientists from Advanced Cell Technologies (ACT), a biotechnology company in Massachusetts, announced that they had cloned the first human embryos for the purpose of advancing therapeutic research. To do this, they collected eggs from women's ovaries and then removed the genetic material from these eggs with a needle less than 2/10,000th of an inch wide. A skin cell was inserted inside the enucleated egg to serve as a new nucleus. The egg began to divide after it was stimulated with a chemical called ionomycin. The results were limited in success. Although this process was carried out with eight eggs, only three began dividing, and only one was able to divide into six cells before stopping. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Genetics, Evolution & Biodiversity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Genetics, Evolution & Biodiversity essays

  1. Marked by a teacher

    An Investigation into the Mitotic Nuclear Division of Allium Sativum Root Tip Cells, and ...

    5 star(s)

    background research collected on the mitotic phase lengths in the embryonic grasshopper cells. The last stage of this process of nuclear cell division, Telophase, also follows the predictions made concerning the observed cellular counts, exhibiting a calculated average of 15 cells, compared to the 21 of prophase, and the 7 of both metaphase and anaphase.

  2. Marked by a teacher

    Human Cloning Assignment

    4 star(s)

    Cloning is not that far from procedures that are being done all the time, such as in vitro fertilization, where egg fertilization takes place in a lab and is then transferred to the uterus. In vitro fertilization usually requires the retrieval of many cells and can take several times to work if it does at all.

  1. Peer reviewed

    The cloning of Dolly.

    4 star(s)

    Arguments for and Against Cloning For There has been a breakthrough with human stem cells. Embryonic stem cells can be grown to produce organs or tissues to repair or replace damaged ones. For example skin for burn victims, brain cells for the brain damaged, spinal cord cells for quadriplegics and paraplegics (the paralyzed)

  2. Recombinant DNA, genetically engineered DNA prepared in vitro by cutting up DNA molecules and ...

    In fact, however, Ab and aB gametes were also formed--the frequency varying for different linked nonalleles. It was therefore surmised that an exchange, or crossing over, took place. Sex Linkage Linked genes occur on the sex chromosomes as well as on the nonsex chromosomes, or autosomes.

  1. Edexcel Level 3 Extended Project - Should Embyonic Stem Cell Research be applied to ...

    it hold great hope and high expectations for this new found research. Like in Cerebral palsy, the new cells could be transplanted into the brain to repair destroyed neurons. The British Heart Foundation (BHF) is very eager about stem cell research, and is very hopeful about its affect on heart tissue damage.

  2. Oncogenes are genes that cause cancer.

    Apparently genetic material from the c-src gene was recombined with the viral genome while the virus was growing in the birds. The virus bearing the reconstituted gene was again fully capable of causing tumors, even though as much as three-fourths of its oncogene had just been acquired from a cellular gene.

  1. DNA cloning or gene cloning

    This has raised concern over GM crops all over the world. GM crops can also have a very bad impact on farmland wildlife due to the harmful chemicals that they produce. Should humans be cloned? Many people are very opposed to cloning humans.

  2. Chromosomes and DNA

    Animal reproduction Animals can reproduce asexually or sexually. It is the simpler animals, such as hydra, that reproduce asexually. Scientists have cloned animals such as tadpoles, and recently a sheep (called 'Dolly'). Humans reproduce sexually. This involves a male sex cell, called a gamete, joining with a female sex cell. Animal reproduction Animals can reproduce asexually or sexually.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work