Tornadoes only form under certain weather conditions. There are three types of airs for a tornado to form, warm humid air close to the ground, cold air in the upper atmosphere, and hot dry air on top that form a cap.(na, 2010) Hurricanes can form tornadoes adding to their destructive power.
Genetically modified crops. Genetically modified crops (GM crops, or biotech crops) are plants used in agriculture, the DNA of which has been modified using genetic engineering techniques. In most cases the aim is to introduce a new trait to the plant which does not occur naturally in the species.
We say that the organism has been genetically modified. Genetic modification works in animals, plants and microorganisms. For example, new genes can be transferred to crop plants to make GM crops. Some GM crops are resistant to certain herbicides (weed killers) while others are resistant to insect pests.enetic modification, or GM for short, is not the same as cloning. Although cloning techniques are used in genetic engineering, the two things should not be confused.