I think the hydra lacks the specialized cells for touch and chemical detection. On the other hand earthworms have touch, light, vibration and chemical receptors along the entire body surface. Both of them are invertebrates (those animals without a backbone), they include insects, worms, jelly fish, spiders among other animals.
Answer:
gas moves more freely because it has loosely arranged molecules
Explanation:
Desert because they are always dry, but in the colder months they can get cold
American prairie, bison and badgers don't live in any of the other options naturally.
Answer:
Not that often
Explanation:
Exponential growth can only occur if there are unlimited resources, no competition or no predators.
