Christopher is learning about the cell theory in science class, and he applies it to a fern that is growing in his bedroom. The cell theory states that which of the following characteristics of the fern must be true?The ferns cells came into existence spontaneously. The fern is made up of a collection of cells. The cells that make up the fern are nonliving. The fern is made up of compounds that are not cells.

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.