The most correct answer is C
This relationship would be called parasitism. Its when one individual lives on or in and feeds on a host organism.
For the first one, electrons travel around the nucleus in fixed energy levels with varying energies.
Second one, protons, neutrons, and electrons have a mass, but electrons have far less mass
Third one, cations and protons
Fourth, not sure.
Animal behavior researchers often refer to an activity associated with punishment or reward as an operant. The basis for training animals is the operant conditioning. It is a learning process where the animal would learn base from its behavior as it responds to its environment. In this type of learning, the behavior is either increased or decreased by the results that follows the action. It uses rewards and punishments in order to associate with the behavior. For instance, you are trying to teach your dog to fetch an object, if he succeeds in fetching the object, then you give your dog a treat. The dog would think that what it is doing is good and that it would get a reward from it so it would start learning the behavior.
The secretion of human growth hormones (HGH) is regulated at the genome level by genetic and epigenetic factors (environment and diet among others). And the expression of the gene of this hormone differs from one individual to another, so the quantity produced differs between individuals, which explains why we observe individuals of different sizes in a population.
Growth hormone acts by interaction with cellular receptors, it affects carbohydrate, lipid and protein metabolism.
A key component of growth is the growth hormone releasing factor or the growth regulating factor (GH-RF or GRF). This chemical messenger is produced in a part of the brain called the hypothalamus. GH-RF allows the pituitary gland (the "master gland" involved in the growth process) to secrete growth hormone, the main hormone responsible for a person's growth.
GH is not only involved in growth phenomena, it also plays a role in the fine regulation of reproductive phenomena in both male and female mammals.
