Since there isn't much prey during winter, the bears have to eat a lot of the remaining prey and then go into sleeping, so that they will not go through the whole winter without food.
Nucleotides is the answer: they have a phosphate group, a deoxyribose sugar, and a nitrogenous base.
Growth factors are hormones, proteins, or steroid molecules that regulate many cellular functions. They can stimulate the cell division by giving the signal to the cell to progress in the cell cycle.
<u>Explanation</u>:
Growth factors are naturally produced within the body and travels through the body to bind to their receptors present on their target cells. These growth factors are capable of signalling the cell to divide, proliferate, or heel. Their main aim is to signal or tell other cell when to do and what to do. Due to the binding with the receptors the growth factors activates specific genes.
