What major explanation did Charles Darwin provide? A) The idea of speciation was first proposed by him.

B) He explained how ​DNA​ is passed on but did not have evidence of it occurring.

C) He was the first to provide an explanation of evolution supported by evidence.

D) He explained how turtles adapted to their environment.

Which of the following is an advantage of using embryonic stem cells in medical research? a. the use of embryonic stem cells is much less expensive than the use of adult stem cells. o b. no living tissue is damaged when scientists use embryonic stem cells. o c. embryonic stem cells are able to differentiate into a wider range of cells than adult stem cells. d. there is no controversy surrounding the use of embryonic stem cells.