Although all of the cells of a human develop from one fertilized egg, the human is born with many different types of cells. Which statement best explains this observation?

a. Developing cells may express different parts of their identical genetic instructions.

b. Mutations occur during development as a result of envirnmental conditions.

C. All cells have different genetic material.

d. Some cells develop before other cells.

a. Developing cells may express different parts of their identical genetic instructions.

Explanation:

Humans are multicellular organisms i.e. we possess many cells in our body. These cells increase as a result of division. Although all of the cells of humans develop from one fertilized egg (zygote), the human is born with many different types of cells because of a process called CELL DIFFERENTIATION.

Cell differentiation is a process in multicellular organisms where a cell becomes more specialized in function as it divides. The set of genes contained in each cell are not expressed simultaneously i.e. some genes are expressed while others are repressed. This is how cells with the same gene possess different functions. Therefore, according to this question, developing cells may express different parts of their identical genetic instructions to be of different types.

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.

enzyme speed up the reactions