Josh notices that the frog he is dissecting has many different types of tissues and cells. the cells are different due to
a) different gene expression.
b) different environmental factors.
c) different dna in the cells of the frog.
d) different rna in the cells of the frog.

The cells are different due to genetic expression. Each type of cells are built from a small DNA template within the entire DNA itself. Each coding region of the DNA will code for a different structure.

Cell division is important to single celled organisms because it allows the cells to reproduce. through cell division, cells make exact copies of themselves. when single celled organisms go through cell division, they make exact copies of themselves which is how they reproduce.