include: producing vaccines in cow's milk, or in food crops that can be easily administered to people by simply eating the food! Insulin and growth hormone can be easily produced by genetically modifying bacteria which go on to reproduce rapidly making a large supply of these drugs available to the public. In the past, insulin was obtained from other mammals' pancreas--a costly and inefficient process. Sometimes plants are genetically modified to allow them to grow in climates they might not normally grow in, or to enhance their nutritional value. In medical research, by isolating a mutated gene that causes a disease in humans, in lab animals, they can shut it down and study the progeny to find treatments or cures in the offspring. Gene therapies are used in people to treat diseases that have a genetic cause. These therapies attempt to change or replace genes that are causing a disease. Some negatives that relate to genetic engineering include: some religious scholars feel that people don't have the right to modify other living things from a religious standpoint, that people shouldn't be able to patent their biological ideas regarding a life form, that perhaps someday this will be used to enhance traits unrelated to health, that the native crops will diminish and the genetically modified crops will replace them, that strains of animals will created solely for the purpose of research, that we don't know the effect of eating genetically modified food--it is too new to know everything. There is a large list of pros and cons for genetic engineering and only time will tell whether the benefits outweigh the risks.

Genetically engineered crops have both pros and cons.

For example, scientists can insert a gene into plants for drought tolerance. If these plants are planted in an area that has a drought, they will be more likely to survive and produce healthy crops. Another pro of genetically engineered crops is pest resistance. Using crops that are genetically modified to resist pests means that less chemical pesticides will be used on them. These kinds of crops can also be modified so that they are resistant to cold weather and disease.

Some cons regarding genetically modified crops are related to the environment. Some people fear that these crops may be harmful to other organisms. In addition, it is feared that pests, such as mosquitoes, will become resistant to these kinds of crops. There are also concerns related to human health such as allergies and other unknown effects.

One of the cons has been the incredible ability of a small group of companies to take over the rights to so much of the world's seeds.  If you look at the news, there are currently those who would like to bring anti-trust suits against companies like Monsanto, but they are so powerful and so large, that it will be difficult to do any great harm.  If you watch Food Inc. you can see some of the problems with genetically modified crops growing next to those that haven't been.  If the new seeds or plants spread into the field that had regular seed, the company that owns the seeds can actually claim the crop on the land which was originally planted with normal seeds as their own.

These crops also tend to encourage the growth of all kinds of resistant pests requiring further modification and further use of different pesticides, etc., driving up prices for farmers and putting them further in debt to their suppliers, a dangerous situation for them and our food supply.

Genetically-modified foods are part of a larger category of "genetically-modified organisms" and frequently abbreviated "GMOs." While the short-term advantages of GMOs are easy to quantify, the long term disadvantages may not be discoverable until they have been in use for many decades, and thus many people are concerned about the long-term effects of their use.

The main advantages of GMOs are that they can be tailored to solve specific problems. For example, GMO crops can be tailored to be resistant to specific pests or diseases. This has an obvious benefit of increasing agricultural productivity. The problem is that pests and diseases evolve quickly, and this year's pesticide or GMO may no longer be effective in a few decades, leading to a constant race between genetic engineers and natural evolution. 

GMOs can also be tailored to adapt to specific environments. For example, plants can be designed to be drought- or heat- or cold-resistant. Again, this can have obvious benefits, especially in light of global climate change. 

A major question concerning GMOs is that they increase the tendency towards monocultures, which are highly vulnerable to both climate change and new strains of diseases and pests. Also, GMO seeds are often more expensive than regular ones and tailored to create plants that do not produce viable seeds, making them especially problematic for farmers in developing countries.