Usually is only because of blood vessels breaking in the skin.
Answer:
Food must be broken down into nutrients for the body to use for energy, development, and cell repair. Before the blood absorbs and transports nutrients to cells in the body, food and drink must be broken down into smaller nutrient molecules.
Answer:
The correct answer will be option-D
Explanation:
Stem cells are the cells which have the ability to form different types of cells. They differentiate and specializes to perform different functions in the body and thus forms the different cells.
The differentiation and specialization are controlled at the gene level by different patterns of gene expression. The pattern of gene expression is not fully understood during development but research have shown that the gene expression is influenced by the different environmental signals and internal regulators.
Thus, option-D is the correct answer.