Why is there a natural limit to human population growth?
a. humans cannot impact limiting factors, so population growth must be limited.
b. human population growth is limited solely by human activity, such as war.
c. humans can reduce the effect of certain limiting factors in the short term, but in the long term resource limitations will impact human population growth.
d. there is a natural limit to population growth, because human reproduction occurs at a very slow rate.

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.

the organisms are not adapted to live in some communities or habitats.