Why do some scientists believe that RNA, rather than DNA, was the first genetic material? RNA can replicate more accurately than DNA.
RNA contains uracil in place of thymine.
All of the protocells on early Earth contained RNA.
RNA has both information storage and catalytic properties.

When a cell is in a solution that has the same concentration of water and solutes as its cytoplasm, the cell is said to be in a(n) solution. a. isotonic b. hypotonic c. hypertonic b. facilitated

Which environmental change would most likely result in bullfrog offspring that are able to store more water than bullfrogs in previous generations?

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.