The Earth is the third planet from the Sun and it is the only planet known to have life on it. The Earth formed around 4.5 billion years ago.[5] It is one of four rocky planets on the inside of the Solar System. The other three are Mercury, Venus, and Mars.
The large mass of the Sun makes the Earth move around it, just as the mass of the Earth makes the Moon move around it. The Earth also turns round in space, so different parts face the Sun at different times. The Earth goes around the Sun once (one "year") for every 365¼ times it turns all the way around (one "day").
The Moon goes around the Earth about every 27⅓ days, and reflects light from the Sun. As the Earth goes round the Sun at the same time, the changing light of the Moon takes about 29½ days to go from dark to bright to dark again. That is where the idea of "month" came from. However, now most months have 30 or 31 days so they fit into one year.
The Earth is the only planet in our Solar System that has a large amount of liquid water.[6] About 71% of the surface of the Earth is covered by oceans. Because of this, it is sometimes called the "Blue Planet".[7]
Because of its water, the Earth is home to millions of species of plants and animals.[8][9] The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of the Earth's surface is called the "biosphere".[10]
The large mass of the Sun makes the Earth move around it, just as the mass of the Earth makes the Moon move around it. The Earth also turns round in space, so different parts face the Sun at different times. The Earth goes around the Sun once (one "year") for every 365¼ times it turns all the way around (one "day").
The Moon goes around the Earth about every 27⅓ days, and reflects light from the Sun. As the Earth goes round the Sun at the same time, the changing light of the Moon takes about 29½ days to go from dark to bright to dark again. That is where the idea of "month" came from. However, now most months have 30 or 31 days so they fit into one year.
The Earth is the only planet in our Solar System that has a large amount of liquid water.[6] About 71% of the surface of the Earth is covered by oceans. Because of this, it is sometimes called the "Blue Planet".[7]
Because of its water, the Earth is home to millions of species of plants and animals.[8][9] The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of the Earth's surface is called the "biosphere".[10]
طيب اعطيني عنوان لهاذا الموضوع وبالله رد اليوم لانه علي اختبار وحيجيب ذي القطعه تكفى بسرررعه وحط اسئله لنفس القطعه ومنشني لما ترد
ردحذفEarth planet of life
حذفEarth planet of life
حذفEarth planet of life
حذفI will talk about الموضوع
حذفطيب اعطيني عنوان لهاذا الموضوع وبالله رد اليوم لانه علي اختبار وحيجيب ذي القطعه تكفى بسرررعه وحط اسئله لنفس القطعه ومنشني لما ترد
ردحذفبالله بسرعة والله سهرانه لحد الحين عشان اشوف انك رديتي
ردحذفأزال المؤلف هذا التعليق.
ردحذفمني حنين مجالي شكرا
ردحذفشكرا كتير كتير
ردحذفارجو الرد باسرع وقت اعطوني اسئلة عليها
ردحذفاذلف
ردحذفبرجراف عن الهندسة الوراسية
ردحذفبرجراف عن الهندسة الوراسية
ردحذفيا معرس
حذف....
حذفGenetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism's genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.
ردحذفAn organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is a genetically modified organism (GMO). The first GMO was a bacterium generated by Herbert Boyer and Stanley Cohen in 1973. Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, Genentech, was founded in 1976 and started the production of human proteins. Genetically engineered human insulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold since 1994, with the release of the Flavr Savr tomato. The Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet, was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.
Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of function, tracking and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines and other drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry detergent, cheeses and other products.
The rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has also been the source of most of the controversy surrounding the technology. This has been present since its early use; the first field trials were destroyed by anti-GM activists. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues. These concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed their own regulatory systems regarding GMOs, with the most marked differences occurring between the US and Europe.
شنو عنوان هااي القطعه
حذفما فيه امترجم
حذفه
ردحذف