Is a knife a biotic factors

No

Explanation:

A knife is not a biotic factor because a biotic factor is a living organism that  shapes its enviroment.

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.

cell division is not regulated in tumor cells.