When doing medical research and human subjects which four limitations are unavoidable

What must be done to breed dogs for a partical trait

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

What happens as electrons move along the chain of molecules known as the electron transport chain? they gain energy, which causes atp molecules to lose phosphate groups. they gain energy, which causes h *ions to join with oxygen to produce water. they lose energy, which is then used by the cell to make atp. they lose energy, which is then used to break down atp.