What happens when electrons are passed down the electron transport chain? a. hydrogen ions are pumped across the mitochondria’s inner membrane producing a concentration gradient. b. the proteins that make up the electron transport chain attach the electrons to adp molecules to form atp. c. the electrons gain more and more energy until they are released from the mitochondrion. d. the concentrations of hydrogen ions on either side of the membrane become more balanced.

Which description provides the best objective summary of the article in the passage?

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.

How and why organisms are hierarchically classifies