Reptile scales! Or, more specifically, reptiles descended from dinosaurs.
Answer:
Are you referring to symbiotic relationships between organism? If so, the answer would be parasitism.
One organism, a parasite, takes advantage of another organism at the expense of the host organism.
Ex. A tick bites a dog for blood to use as food. The dog gets an uncomfortable bug bite and the dog might catch a tick borne disease.
Answer:
c. because arteries carry high pressure blood from the heart
Explanation:
Arteries carry the oxygenated blood that is pumped directly from the left ventricle of the heart. Since they receive blood from the heart, the blood pressure is higher in arteries than veins. To withstand the higher pressure of blood pumped by heart, arteries have thicker walls than the walls of veins.
