Studying fossils allowed researchers to learn about organisms that lived long ago. The fossils provide as evolutionary evidence that shows how organisms in our present time have evolved over time and which common ancestors they are tied to. Fossils also provide information about climate change depending on the region and location they are found in. Fossils also date back to millenias ago, so fossils dated very far back in the past can help researchers infer that life had existed even farther than what they might have discovered. And finally, by studying fossils, you can determine how the organism may have died.
A.some of the genetic material is altered
One reason is that they die and new cells are needed to replace them. If you're cells didn't divide you would die with them. After a while, all cells in you're body are replaced and you are physically not the same man you were before because the set of cells is not the same one.
Maintaining life on earth<span />
Trisomy 21, as illustrated by the karyotype, is caused by nondisjunction. This occurs when chromosomes do not separate properly during meiosis.
Answer is D) nondisjunction