Juan has collected a cricket. Which question can a dichotomous key help him answer?
A. Are crickets attracted to porch lights?
B. Which species of cricket is this?
O C. Which species of cricket is the most popular?
O D. How many times do crickets chirp per minute?

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.