The agent of erosion that makes a rock fall from high places is a) water b) wind c) ice d) gravity

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

When fossil fuels are burned, carbon dioxide is released. how does this gas impact the environment?

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.