GENETICS. Definition, uses, disadvantages, advantages of selective breeding, genetic engineering, cloning and artificial insemination.

Essay by 0High School, 11th gradeA+, June 2004

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A) SELECTIVE (ARTIFICIAL BREEDING)

Definition: Selective breeding is when the plants/animals from the existing stock that have the characteristics they want are selected and are allowed to breed. The offspring will hopefully display the characteristics which are required. The best offspring are then bred from, until all offspring display the characteristics that are wanted. This leads to new breeds of animal being produced.

Uses:

* High yielding crops, such as wheat are produced by collecting the seeds from only the plants that have a good yield of wheat.

* Disease resistant crops can be developed.

* Animals on farms are bred so that they produce more food, e.g. cows with better meat, hens that lay more eggs.

* Animals such as dogs and cats are bred for fashion. They may also be bred to do a particular job (e.g. sheepdogs).

Advantage: Humans will get the breed of a plant or animal that has all the characteristics that they want when they can manipulate it to their liking.

This could be used for several purposes, and could assist humans greatly.

Disadvantage: There are many ethical concerns where people claim that we are 'acting as God' and it is somehow immoral. There is also the risk of mutation which could lead to unwanted consequences.

Impact on society: The impact on society will depend on to the extent of where the manipulation of plants and animals is taken. If it is generally mild, the majority of society may accept it, however there are also ethical issues involved and religious groups could be strongly against it.

B) GENETIC ENGINEERING

Definition: Genetic Engineering is the alteration of an organism's genetic, or hereditary, material to eliminate undesirable characteristics or to produce desirable new ones.

Uses: Genetic engineering is used to increase plant and animal food production; to help dispose of industrial wastes; and to diagnose disease, improve medical treatment, and produce vaccines and other useful drugs.

Advantage: Whatever is altered, it may look more appealing. It could also reduce the amount of mutation that is found in animals. This could assist humans.

Disadvantage: Animal rights groups have argued that the production of transgenic animals is harmful to other animals. Genetically engineered fish raise problems if they interbreed with other fish that have not been genetically altered.

Transgenic plants also present controversial issues. Allergens can be transferred from one food crop to another through genetic engineering.

Impact on society: Once again, Genetic engineering will advantage society however there are always disadvantages. If this is done on animals, and if something goes wrong, the humans who ate it could possibly get sick, but this is only one example.

C) CLONING

Definition: Cloning is the production of one or more individual plants or animals (whole or in part) that are genetically identical to an original plant or animal.

Use: Children who are in desperate need of organs such as a kidney, or bone marrow transplant if cloning were an option. The parents could choose to clone the child in order to produce another human being to donate whatever is needed.

Advantage: Cloning could offer a way for infertile couples a way to reproduce, when otherwise could not. It could offer the gift of life to those who might not be able to obtain it by other means.

Disadvantage: There is the risk of abuse of the technology. What would Hitler have done with cloning technology if it was available in the 1940's? There are powerful leaders in every generation who will seek to abuse this technology for their purposes. Going head with cloning technology makes this far more likely.

Impact on society: Cloning is probably the most controversial. It would impact society greatly and cause confusion, that is, if it is legalized. It could lead to all types of consequences, and if someone took advantage of this, clones may not be treated equally and perhaps put into slavery.

D) ARTIFICIAL INSEMINATION

Definition: The placement of a sperm sample inside the female reproductive tract to improve the female's chances of getting pregnant.

Uses: The main use of artificial insemination is too assist a female in getting pregnant.

Advantage: Artificial insemination is less invasive and less expensive than assisted reproductive technology treatments such IVF.

Also, couples with male factor fertility problems have an easier time conceiving through artificial insemination than through just timing intercourse. And couples with unexplained fertility problems see better results with artificial insemination than with the help of fertility drugs alone. The procedure also allows for fertilization to occur naturally inside your body.

Disadvantage: Because timing of the insemination is so crucial, your partner must be able to quickly produce a sperm sample by masturbating into a cup at your doctor's office or clinic. You'll both also have to be available and ready to go to your doctor's office at the exact moment of ovulation.

Impact on society: If artificial insemination was more readily available to couples there could be more successful birth rates because it is much cheaper than IVF.

E) IN VITRO FERTILIZATION

Definition: The mother's eggs and the father's sperm are collected by doctors who fertilize the eggs in a laboratory (which led to the term "test tube baby") and then implant them into the mother's uterus. Usually several eggs are implanted at once, as this method has a low success rate. Most couples do not become pregnant on the first attempt, though with repeated (though expensive) attempts, many parents have had success with this method.

Uses: In Vitro Fertilization is a method to help infertile couples to have a child that is biologically related to both parents.

Advantage: The major advantage of day 5 transfer is embryo selection. The implantation rate per day 5 blastocyst transfer is greater than for transfer of day 2 or 3 embryos. But only 20 percent to 50 percent of day 2 embryos can develop in vitro to day five no matter how perfect the in vitro culture system. There is a potential loss therefore of what could have been viable embryos. So selection is the only advantage of blastocyst culture, and this selection has nothing to do with the "quality" of the baby, but rather just whether the embryo "makes it" or not to becoming a baby.

Disadvantage: For some patients with poor quality embryo development, even with the best culture media, the embryos may be better off going directly into the fallopian tube immediately. For the average patient, day two or day three transfer either to the fallopian tube or to the uterus may be best. For some patients, day 5 transfer to the uterus may be a good option. The problem with extended culture to day 5 is that there may be a loss of some embryos that might have "made it" if they had been transferred earlier. No "in vitro" culture system is as good as the fallopian tube itself.

Impact on society: Couples who cannot have children for their own reasons could have the joy of having they're own baby; however there are still ethics involved regarding religion. Such as; it is not the 'normal' way of conceiving a child and we are acting as God.