Dogs and pigs are members of different species because:

A. of prezygotic barriers to their ability to breed.
B. hybrids between them are infertile.
C. one is a predator, and the other is prey.
D. they are at the far end of the ring in a ring species.

C. One is a predator, and the other is prey.

Explanation:

They are not the same animal and they may not like each other, one may be friendly and the next one is not.

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.