Both dolphins and whales still have their hip (pelvic) bones present. These bones connect and transfer the weight of the trunk to the lower limbs.
Thus, <em>the presence of the pelvic bone may indicate that whales had ancestors that walked on land</em>.
The correct answer is: Protons are pumped out of the mitochondrial matrix into the intermembrane space
Chemiosmosis can be described as movement of ions across a selectively permeable membrane, down their electrochemical gradient. It occurs during the cellular respiration within mitochondria and it is involved in ATP synthesis (oxidative phosphorylation via ATP synthase).
Electrons from electron carriers (NADH and FADH) donate electrons to the electron transport chain and that causes changes in protein complexes of electron transport chain. As a consequence, protein complexes pump H+ across a selectively permeable cell membrane from the mitochondrial matrix into the intermembrane space of mitochondria.
H+ can only get back and pass through the inner mitochondrial membrane with the help of ATP synthase (down their electrochemical gradient). ATP synthase turned by the force of the H+ diffusing through it forms ATP by adding a phosphate to ADP.
Tons of rain can cause an ecosystem to flood, killing species that are not meant to withstand lots of water. Ocean temperature can slow down or speed up evaporation, affecting precipitation rates.
Hope I helped!
~ Zoe