All cells in an embryo have the same dna. however, the embryonic cells form organs, such as the brain and the kidneys, which have very different structures and functions. these differences are the result of: ) having two types of cells, one type from each parent(2) rapid mitosis causing mutations in embryo cells(3) new combinations of cells resulting from meiosis(4) certain genes being expressed in some cells and not in others

Explanation:

The DNA is present in every cell of the multicellular organism but that does not mean that every cell will perform the same function.

The function of the cell is decided during the cell differentiation phase the function of the cell is determined by the expression of specific genes. Expression of these genes controls the functions of the cell.

In the given question the differences in the structure and function of the brain and kidney arise due to different expression of genes in different cells.

Thus, the selected option is the correct answer.

a. the production of carbon dioxide through the process of photosynthesis