Answer:
D. A nucleus
Carbon contains four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules. The simplest organic carbon molecule is methane (CH4), in which four hydrogen atoms bind to a carbon atom
D all of the above is the answer
Answer:
D. physiological mechanisms are the basis of behaviors.
Explanation:
The example of the development of electric fields as part of the communication between some fish, shows the interrelation that exists between physiology and behavior. This physiological factor that fish have has an impact on their behavior. However, it is necessary to recognize that physiology does not act by itself, but needs to receive a stimulus from the surrounding environment.
This way of communicating is called electrocommunication, a fish generates through its physiology an electric field and a second individual receives that electric field with its electroreceptors.
Human activities contribute to climate change by causing changes in Earth's atmosphere in the amounts of greenhouse gases, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas to the atmosphere.
Answer
Elastin fibers are glycoproteins found in the lungs and are usually in large quantities. The abundant elastin fibers are helpful in the recoil process of the lungs after being expanded by the muscles of the respiratory system.
During inhalation,the diaphragm and intercostal muscles expand the chest. This forms a negative pressure and draws the air in.The Lungs recoil to expel used up air during exhalation.
