For example, what are the advantages and disadvantages of using genetic engineering?

Viewpoint: Look at the pros and cons of genetic engineering dialectically.

Genetic engineering can be used to screen and treat genetic diseases.

Genetic diseases are caused by the wrong genes of the father or mother. Gene screening method can quickly diagnose the error of gene coding; The rule of gene therapy is to use genetic engineering technology to treat such diseases. Prenatal genetic screening can diagnose whether the fetus is hereditary.

Disease, this screening method can even diagnose embryos fertilized in vitro, which are as early as two days old and are still in the eight-cell stage.

In vitro embryo. The method is to take out one of the cells, extract DNA, test whether its gene is normal, and then decide whether to implant the embryo into the mother's uterus for development. Fetal sex can also be measured.

But extensive genetic screening will cause a series of social problems. If someone receives genetic screening and finds that he will die of a certain disease at a certain age, it will definitely change his outlook on life. Although genetic screening can help doctors treat patients earlier and more effectively, it may hinder their future life and employment. For example, life insurance companies will require customers to provide family health data, such as heart disease, diabetes and breast cancer, and set higher premiums for family members of high-risk groups. Insurance companies can predict the life expectancy of customers from genetic screening data. These people may not be taken care of by insurance, or they may be dismissed early by the company boss.

2. The combination of genetic engineering and reproductive technology-the shock of all mankind

Gene screening will not change people's genetic makeup, but gene therapy will. Scientists are trying to change the wrong genes of genetic patients and send good genes into them to correct the mistakes. Because this is the basic problem of operating life, you must be extra careful. First of all, we should distinguish between medical behavior and non-medical behavior. The purpose of medical behavior is to cure diseases, and non-medical personnel want to improve the height and wisdom of children. Choosing the sex of the fetus is also a non-medical behavior and unacceptable, but it is an acceptable medical behavior to choose the sex of the fetus in the face of some sexually transmitted diseases. Another thing to be distinguished is the genetic manipulation of somatic cells or germline cells. The gene manipulation of somatic cells only affects somatic cells of the body, not offspring. However, the genetic manipulation of germ cells such as eggs and sperm will directly affect future generations. At present, it is forbidden to use genetic engineering directly on germ cells.

Three. Gene therapy-the gospel of genetic patients

At present, the medical community is conducting clinical trials of gene therapy for various genetic diseases. The earliest gene therapy is a congenital immunodeficiency, also known as bubble boy disease. Due to the defect of adenosine deaminase gene, the bone marrow of sick infants can't produce normal white blood cells to play their immune function, so they have to live in an air hood completely isolated from the outside world. The latest treatment method is to isolate the stem cells of white blood cells from patients' bone marrow, and connect the normal enzyme gene with the modified nontoxic retrovirus, so that the virus can be sent to the stem cells of white blood cells, and then the stem cells can be sent back to patients, so that patients can produce healthy white blood cells and obtain immune function. This clinical trial has proved to be very successful for female sick children in the United States.

Another more convenient treatment is also in the experiment. In Britain, one in every two thousand people suffers from fibrocyst. Patients cannot make protein that forms chloride ion channels in cell membranes. This protein is distributed on the membrane of secretory cells, which controls the transport of chloride ions and makes mucus smooth. Due to the lack of this protein in patients, viscous mucus in the body accumulates and blocks lung passages, and even dies due to inflammation. In order to treat this disease, a new method is being developed, in which normal genes are added to mist spray, and patients can inhale the spray to make genes enter lung cells to produce protein, thus achieving the therapeutic purpose.

4. Application of agriculture, forestry, fishery and animal husbandry-paying attention to ecological environment protection.

At present, the whole world is paying attention to the development of sustainable agriculture, hoping that agriculture will not only have economic benefits, but also be endless and will not destroy the ecological environment. Genetic engineering can help solve this kind of problem. Genetic engineering can improve the nutritional composition of crops or enhance the resistance to pests and diseases. It can improve the growth rate of livestock and poultry, the milk yield of cattle and sheep, and improve the meat quality and fat content.

Scientists in Edinburgh, England, have been able to make sheep secrete goat milk containing human antitrypsin (α- 1- antitrypsin). Antipancreatic protein can treat hereditary emphysema, which is very expensive. If you can make a lot of goat milk in the future, it will become very cheap. However, at present, the process of developing transgenic sheep through genetic engineering is still very time-consuming and expensive.

Transgenic bacteria are also very useful. For example, modified bacteria can digest garbage and waste paper, and these bacteria can become a kind of

Nutrient sources in protein. Transgenic bacteria can carry human genes and produce medical insulin and growth hormone.

In fact, the application of genetic engineering in agriculture is not uncommon in some aspects. Since ancient times, people have tried to carry out breeding in a planned way. For example, a new kind of wheat has been bred through repeated hybridization for thousands of generations. At present, Mai Hanxu.

Most of them are derived from wild rye genes. Long before the invention of genetic engineering technology, farmers knew how to transfer genes from one organism to another. Traditional breeding can also greatly increase the yield. However, the traditional breeding process is slow and the results are often unpredictable. Genetic engineering can select specific genes and send them into organisms, which greatly improves the efficiency of breeding, and can also send genes into organisms with far different classifications, which is impossible for traditional breeding. Soon, tomatoes cultivated by genetic engineering will be listed in the United States. This kind of tomato contains antisense gene, which can prevent tomato from softening and rotting after ripening.

Genetic engineering also produces disease-resistant and insect-resistant crops, so that the crops themselves produce "pesticides", so that farmers don't have to bother spraying pesticides, so that we have a healthy living environment. It is also possible to cultivate drought-resistant and salt-tolerant crops and make them grow in harsh environments, thus overcoming the food shortage in the third world. However, crops that produce pesticides may also be harmful to the environment. They may kill unexpected beneficial insects and affect the ecological balance of insects. Planting genetically modified crops in high-salt marshes may interfere with the ecosystem. If tropical crops are transformed to grow in temperate regions, it may seriously damage the economy of developing countries, because the output of crops and fruits is their main income. Recently, it has been gradually discovered that pests that harm crops have gradually evolved and become resistant to "pesticides" produced by genetically modified crops. Genetically modified fish also caused a series of problems. At present, two genes have been sent to carp, one is growth hormone and the other is antifreeze protein. If someone accidentally or intentionally puts these fish into rivers and lakes in the natural environment, it will seriously affect the fish ecology in nature.

Five, genetically modified animals-animal lovers' concerns

Transgenic animals are a great gift for biomedical research. Scientists can now send genes to mice in the laboratory to study the function of gene expression regulation. It is also possible to deliberately destroy a gene of experimental animals and cultivate animals with genetic diseases similar to humans, so as to facilitate the discussion of treatment methods. An American company has developed a transgenic mouse, which will develop cancer when it is a few months old. The invention is being patented. However, animal lovers express serious concern that genetic engineering technology should be restricted and experimental animals should not be tortured and abused.

(Note: The application of genetic engineering is not limited to the above parts. I only express my personal views in the above part. )

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In the near future, genetic engineering technology will still be limited to the transfer of a few genes, and the organisms cultivated from it will still be familiar to us. However, many diseases and biological characteristics are determined by most genes, and genes often do not play an independent role and will be affected by the environment. For example, a set of genes can cause someone to suffer from asthma, but the symptoms are greatly affected by the living environment. The probability of a person suffering from diabetes is also closely related to environmental factors (diet). A talented pianist's musical talent includes the ingenious coordination of listening and sensitive hands, which is related to his genetics, the inspiration of childhood music and the living environment. Therefore, before we know the interaction between genes and environmental factors, we can't expect to create people with super-high IQ or screen children with special talents through genetic screening.

2 1 century is the era of vigorous development of genetic engineering technology, and the rise of genetic engineering is the inevitable result of biological revolution. Although there are different opinions about the hidden dangers and debates of genetic engineering, its benefits are obvious. I hope that with the continuous development of biology, the safety of genetic engineering can be guaranteed, and people can feel the benefits of genetic engineering in all aspects of life.