Explain what was happening to Usain's respiratory and circulatory systems whilst training?

carbohydrates are the body's preferred source of energy.

interphase   is the cell cycle stage in which the cell acquires nutrients, creates and uses proteins and other molecules and starts the process of cell division by replicating the dna. it is the longest stage in the eukaryote cell cycle.

the following   can go wrong during interphase:   a base pair could be mismatched during the duplication process causing a mutation.   correct answer: c

explanation:

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.