Skim coating weak concrete is only a temporary fix. Another option is to lay a thicker overlay and slow-dry the new surface. To slow-dry, cover the driveway with moist, breathable material. Keep the material wet to provide additional moisture for the concrete to absorb.
The two main sources of genetic variation are gene shuffling and  mutations. A mutation is a process wherein the structure of a gene  is altered.Edit. Share to: Blobbert. 37,033 Contributions. Answered.In Genetic Engineering.he 4 types of genetic variation are 1) mutation-is the mutation of a gene. this is really rare, most mutations are in the recessive trait so they are hidden by a dominant t â¦ rait. Most mutations have no effect but some can be harmful and very few have positive effects.
The second main cause of genetic variation is due to the high degree of neutrality of most mutations. Most mutations do not appear to have any selective effect one way or the other on the organism. The main cause is genetic drift, this is the effect of random changes in the gene pool.