1.   Before the adult cell is used to start cloning, scientists could alter it.

2.   Cloning is a prerequisite for genetic engineering, the process by which scientists alter or add genes to an embryo.

3.   Infectious disease scientists might alter the bacteria during research to find more potent antibiotics or during research to determine why certain medicines are losing their effectiveness.

4.   Scientists have been altering the genes of mice for years.

5.   Scientists altered his genes before he was born.

6.   The other, identical image, can be altered by scientists on the ground, for clarity or color, whatever they want.

7.   The scientists have genetically altered a bacterium that resides inside the bug to produce a protein that fatally punches holes in the parasite.