The correct answer is C. Short tandem repeats are mostly different in unrelated peoples' DNA. Therefore, it is used to match the DNA of the people of the related family for identification of bodies, during a mass disaster like World Trade Centre. DNA from the nucleus is extracted in the process, and the STR containing regions are amplified and studied and can be matched with that of the relatives.
<span>Scientists first developed the geologic time scale by studying rock layers and index fossils through out the whole world. With this information, scientists placed Earth's rock layers in order by relative age. Later, radioactive dating helped determine the absolute age of the divisions in the geologic time scale.</span>
When this happens gasses dissolved in the magma are able to come out of solution, forming gas bubbles (the cavities) inside it. When the magma finally reaches the surface as lava and cools, the rock solidifies around the gas bubbles and traps them inside, preserving them as holes filled with gas called vesicles.
