Four substances are involved in both photosynthesis and cellular respiration. They are sugars, water, oxygen, and carbon dioxide. Energy is also transformed from one type to another. Describe what happens to these four substances, light energy, and chemical energy during photosynthesis. Then write a simple equation for the substances and another for energy, using words and arrows to illustrate these changes.

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.