Answer:
Letter C
Explanation:
Salmon have a physiological adaptation that allows osmoregulation to occur in two different environments (seawater and freshwater). There are specific molecules in the salmon gills that "pump" and "remove" Na and Cl ions. When at sea these molecules pump the ions out of the salmon's body and into freshwater, the same molecules remove Na and Cl from the water bringing it into the animal's blood.
Answer:
Scientists once thought the most fundamental building block of matter was a particle called the atom. Now we know that the atom is made of many smaller pieces, known as subatomic particles. Every atom contains a central core called the nucleus, made of particles called protons and neutrons.
Flagella and cilia are both used for movement
Human encroachment that has greatly reduced the prairie dog populations.