Answer: As each cell differentiates, the <em>DNA </em>changes so that each type of cell has different <em>DNA</em> once it reaches maturity. Mutations in the cells’ nuclei lead to new combinations of <em>DNA</em>, resulting in different shapes and functions in the different types of cells.
Hope this helps!
Do you have a picture or something?
Answer:
1. hydrogen; 2
2. it means two strands of DNA twisted around each other like a winding staircase
