Jealousy is one of the main reasons for conflict in families and societies. It is normal for parents to care for the younger sibling or the one who needs more supervision. Parents love cannot be measured in any way so therefore we should understand the situation instead of being jealous or insecure about it.
As an energy source, To heal and build and repair tissue, To sustain growth, To help transport oxygen to the cells, To regulate body functions. hope this helped :)