The earliest known frog appeared on Earth about 200 million years ago. Since they are still around today, you have to say they are doing a good job of surviving! Frogs have certain adaptations that have allowed them to be around for such a long time. Adaptations are behaviors or characteristics a plant or animal has that makes it better able to live in a certain place or situation.
Over time, frogs have adapted their eyes, legs, and skin to be able to survive in their environment. Not all frogs have the same adaptations though; there are over 6,000 different types of frogs that live in many different environments. Some frogs spend more time in water, while others have adapted to living on land better.
Because there's a higher concentration of oxygen molecules outside the cell compared to the cell's cytoplasm, you'll see that oxygen diffuses into the cell along this concentration gradient. ... Because the molecules are moving at random, some will move out of the cell, but most will be moving in in this case.
