<span>A. Mammals use a closed, double-loop circulatory system aided by a four-chambered hearts.
The four chambered heart of a mammal is divided into two atria and two ventricles. Double-loop circulatory system is used. One loop for oxygenated blood, the other loop for deoxygenated blood.</span>
Answer:
Plants are not an example of an abiotic factor
Explanation:
Mountain that forms in the Earths crust when molten material, or magma, reaches the surface.
Answer:
Biological evolution is supported by the fossil record. When you start to dig you find dead animals we have today, but if you dig a little deeper, you start to find animals that are similar to animals we have today, but slightly different(mastodons, wooly mammoths, sabertooth tigers). If you keep digging the animals keep getting more and more different. After you go back 200 million years you stop finding mammal fossils and start finding all reptile fossils. These reptile fossils keep getting smaller and smaller, and then become aquatic creatures, and then soon only small water organisms are found. Hopefully this helps.
Explanation:
The answer is phototrophism
