Some sorts of reptiles are alligators, crocodiles, turtles, and snakes. And some amphibians are salamanders, toads, frogs etc. One difference is between the structures of their skin. Reptiles are covered with scales, shields, or plates and their toes have claws.mphibians are animals that can live on land or in water. They spend part of their lives under water breathing through gills and part of their lives on land breathing with lungs. Amphibians are characterized by glandular skin and no scales.
Humans need oxygen to live, but not as much as you might think. The minimum oxygen concentration in the air required for human breathing is 19.5 percent. The human body takes the oxygen breathed in from the lungs and transports it to the other parts of the body via the body's red blood cells. Each cell uses and requires oxygen to thrive. Most of the time, the air in the atmosphere contains the proper amount of oxygen for safe breathing.
Understanding your blood oxygen levels when you are at rest is something that you need to do if you want to make the most of the oxygen that's entering your body. Normal blood oxygen levels for the average American is about 90 to 100 percent oxygen saturation.This means that your body is getting enough oxygen if your levels fall somewhere in this range.nderstanding your blood oxygen levels when you are at rest is something that you need to do if you want to make the most of the oxygen that's entering your body. Normal blood oxygen levels for the average American is about 90 to 100 percent oxygen saturation.