A climber at altitude has potential energy due to efforts to lift him higher in gravity's grip. His elevation gives him the potential to create kinetic energy if he had the misfortune to fall off
The more you observe, the more you catch on
Vertebrates developed about 550 million years ago. The oldest vertebrate fossils are those of FISH with no jaws. These e<span>arly jawless fish did not have paired fins and their bodies were covered with heavy, bony scaled, but their skeletons were made of cartilage. For the next 50 million years, they were the only vertebrates.</span>
<span>Having more lung capacity is advantageous because the lungs can expand more. More air in the lungs will fill all the alveoli (air sacs in the lungs) and allow more oxygen to enter the bloodstream via the capillaries that surround the air sacs. Excess waste (such as carbon dioxide) is also transferred from the blood to the air to be exhaled. As lungs fill, more gas exchange can occur.</span>
Plant cells have all of these, but only a plant cell has a chloroplast.
