What are the similarities and differences between the reactions that lead to the activation of trimeric g proteins (g protein-coupled receptor signaling pathway) and those that lead to the activation of ras (enzyme-coupled receptor signaling pathway)?

24. how are vaccines used to keep people healthy?

Cells control gene expression at which steps

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.